Saturday, September 16, 2017

Today's Straits Times Article On Hydration

Straits Times article 160917 page C13 under Sport section
Every morning when I pick up the newspapers, I'll usually turn to the sports section first. Today, I happened to look at the article on the training plan for those planning to run the Singapore marathon at the end of the year. "Right hydration integral to a successful race". I thought the article was well written. Fairly straight forward and simple to understand. Also mentioned that over drinking water can lead to hyponatremia.

Wrote about about sports drinks. Though you need to know that sports drinks cannot replace or even maintain your sodium levels during exercise or racing.

Just wanted to point out that the two percent loss of body weight (through sweating) during endurance exercise/ racing affecting your performance may not be totally accurate.

I wrote about it before earlier in the year that latest published research suggest that current hydration guidelines may well be wrong.

Two published studies on cyclists and elite male marathoners (including Haile Gabreselassie during 13 major city marathons) showed that weight loss up to three percent did not slow the runners down nor decreased the cyclist's power output.

In fact Gabreselassie lost 9.8 percent of his body weight during the 2009 Dubai marathon and still won the race in 2:05:29 hours! All drinking by the elite runners were ad libitm (or at their own time and pleasure).

Yes I do agree that the quoted study was done on elite runners. How does that apply to us in super humid and sunny Singapore?

My own thoughts are that the sports drink companies definitely recommend us to drink to much. I wrote before that I definitely drink less than my fellow team mates and competitors. From the time I started running cross country as a twelve year old kid to when I was racing triathlons. Even now during my weekly group bike ride. Most of the other cyclists carry two or more water bottles while I survive the three hour ride on one.

In fact I often had a side stitch after drinking while running cross country as a kid. That also deterred me from drinking too much then.

Of course this does not mean you try not to drink at all in your next long run/ ride and especially your next race. What I'm suggesting is that you at least give it a try in your next few long bike or run sessions.  Everyone is different. Try to get through those long sessions drinking as little as you can. You might be pleasantly surprised that you may not need as much fluid as you think.



References

Beis LY, Wright-Whyte M, et al (2012). Drinking Behaviours Of Elite Male Runners During Marathon Competition. Clin J Sport Med. 22(3): 254-261. DOI: 10.1097/JSM.0b013e31824a55d7.

Wall BA, Watson G et al (2015). Current Hydration Guidelines Are Erroneus: Dehydration Does Not Impair Performance In The Heat. BJSM. 49(16): 1077-1083. http://dx.doi.org/10.1136bjsports-2013-092417.

Friday, September 8, 2017

Lumbar Spondylolistheis But No Real Deficits So Far


Have a look at the MRI and you can see a very obvious spondylolisthesis in my 38 year old patient's lumbar spine at the L5-S1 area. The last time I saw one so obvious was when I was working at the Singapore Sports Institute in a young gymnast in 2001.

Spondylolisthelis is a condition in which one vertebra slides forward over the vertebra below it. In simple terms, it means that there is a forward slip of one vertebra relative to another.

From what my patient says, there wasn't any traumatic incidents. He complains of lumbar area aches in the past year.  Often there is discomfort over his L buttock and tightness down his L outer thigh at the end of the day. He is still able to exercise including running and playing football. Other than that he hardly has any other symptoms.

His surgeon has suggested surgical intervention to stabilize his spine at the end of next month. Looks like lots of rehab after surgery.


Saturday, September 2, 2017

How Singapore Can Solve Our Diabetes Problem


In our National Day Rally, Prime Minister Lee Hsien Loong highlighted that 1 in 9 Singaporeans has diabetes. And of these, an average of 1200 undergo amputations every year!

I was quite shocked at the sobering figures that he cited. Three in 10 Singaporeans above the age of 60 have diabetes. If you break in down by race, 2.5 in 10 Chinese over 60 have diabetes, half of Malays over 60 years old and six in 10 Indians over 60 are affected.

PM Lee then urged Singaporeans to get regular medical check ups to know if they are diabetic or are at risk and suggested solutions to counter it. He then recommended that Singaporeans exercise more, suggesting that the easiest way to do so is "just walk  a little bit more every day".

If possible, I would definitely suggest including weight training (also known as strength training or resistance training).

In case you think weight training is only for bodybuilders pumping iron for beefy biceps and bulging pecs, current evidence shows that weight training - whether with a light dumbbell or your own body weight may be the best exercise for lifelong overall function and fitness.

Here's what most important. Research has shown that weight training helps with improved insulin sensitivity among people with diabetes and pre diabetes. Twice weekly weight training sessions helped control insulin swings (and body weight) among older men with type-2 diabetes.

During weight training, our muscles are rapidly using glucose (or blood sugar). This energy consumption continues even after you finish your strength training session. This is especially beneficial for anyone at risk for metabolic conditions like Type-2 diabetes, high blood pressure, and unhealthy cholesterol levels making weight training the most effective remedy.

In addition, weight training can strengthen our bones and improve our posture through bone remodeling. Weight training stimulates the osteoblasts (bone building cells) to build more bone. Weight training is also superior to aerobic exercise for enhancing and maintaining total body bone strength. And that's probably another post.

That's why I bought a Olympic bar, squat rack and got some free weights earlier this year as I realize I was losing muscle mass. Here you see Ting Jun trying out the Olympic bar with Rachel's help.




Reference

Ibanez J, Izquierdo M et al (2005). Twice-Weekly Progressive Resistance Training Decreases Abdominal Fat And Improves Insulin Sensitivity In Older Men With Type 2 Diabetes. Diabetes Care. 28(3): 662-667. DOI: 10.2337/diacare.28.3.662.

Thursday, August 24, 2017

Kinesio Taping At Raffles Institution


A few weeks ago I received a call from the Physical Education Head at Raffles Junior College (or known as Raffles Institution now) to teach their PE teachers Kinesio Taping. They had seen an increase of self taping by their students in school especially during PE classes and/ or training sessions. They needed to know if the students were doing it correctly as most were just following instructions looking at youtube.

Just so you know, participants who have attended the Kinesio Level 1-2 courses must sign a disclaimer that they cannot post any videos of what they've learnt online. Hence, whatever videos you can find online are not the real Kinesio Taping techniques but are from other copycat or imitation tapes.

So there I was showing the PE teachers there from year 1 to 6 some pointers on how to tape. The emphasis was on understanding concepts rather then simply giving them "recipes" on how to tape.

We've had lots of people asking when Sports Solutions will be hosting the next Level 1-2 Kinesio Taping course where they even learn about what the homunculus has to do with Kinesio Taping.

Well, I was informed by Kinesio Taping International that they were tweaking the Level 1-2 course from June 2017 onward. They were making some changes to the course world wide. As of now, the Kinesio Taping Instructors recertification courses are slated to take place between October 2017 to January 2018 in USA, South America, Europe and Asia.

I need to clarify some of the content changes at the next Kinesio Taping Instructor Recertification course that I will only attend in early January 2018. I want to ensure that I'm not shortchanging the future participants that I teach. Hence, I've decided I'll only teach the next Level 1-2 course after I've attended the next Instructors Re-certification early next year.

Yes, Kinesio Taping Instructors have to re-certify themselves every three years to be able to keep teaching.

We will definitely inform those who keen to attend the next Kinesio Level 1-2 taping course on our website and Facebook page when dates are finalized.

Saturday, August 19, 2017

Can Sports Injuries Lead to Osteoarthritis In Your Joints?


Picture by Liji Jinaraj from Flickr
The first question I get always get asked when an injured athlete sees me in our clinic is "How quickly can I get back to training?"

Actually it's not just the athletes, every single weekend warrior or physically active patient that I see will ask when they can get back to their usual activity or exercise.

I'm guilty of doing the same. That's exactly what I asked my doctor after my bicycle accident.

There is now evidence to show that if you rush to get back to playing, whether as part of a team or elite sport or simply just your usual weekly recreational tennis game or jogging you may not allow the injured joint to heal fully.

Adequate recovery includes strengthening the structures the support the injured joint. This will allow joint stability to reduce risk of re-injury and stave off irreparable joint damage. If you're not careful, irreparable joint damage can eventually lead to post traumatic osteoarthritis (OA).

OA is a degenerative joint disease. It happens when the protective articular cartilage lining the surfaces of bones wear out. This causes pain, stiffness, swelling and often disability that diminishes one's quality of life.

Post traumatic OA don't just happen to older patients. It can affect adolescents or young adults too.

Researchers suggest that acute joint damage can lead to a deterioration of the surface of the bone itself and structures that cushion and stabilize bones of a joint like the knee (Anderson et al, 2012).

That same study found that OA can develop in more than 40 percent of people who seriously injure their ligaments, the meniscus in the knee or articular surface of a joint.

They also found that people with a history of knee trauma are three to six times more likely to develop knee OA.

In order to better manage post traumatic OA, a group of Athletic Trainers (ATC) has suggested a more aggressive approach to both preventing and managing post traumatic OA. Especially in younger patients who get injured playing sports.

They suggested that having less deficits (between both legs) in muscle strength, endurance, balance movement quality and stability will reduce a person's risk of getting injured. After the initial injury, it should be properly managed to prevent additional injuries to the same joint or other joints to minimize OA developing. Ideally a structured rehab program should be maintained for six to nine months.

So don't be too impatient to return to your usual physical activity especially after a joint injury. You may have to modify the activities you do in order not to place unnecessary repetitive stress on the injured joint. Remember our articular cartilage likes and needs weight bearing forces for nutrition. Inactivity will cause the articular cartilage to deteriorate.


References

Anderson DD, Chubinskaya S, Guilak F et al (2012). Post-traumatic Osteoarthritis: Improved Understanding And Opportunities For Early Intervention. J Ortho Res. 29(6): 802-809. DOI: 10.1002/jor.21359

Palmeri-Smith RM, Cameron KL, DiStefano LJ et al (2017). The Role Of Athletic Trainers In Preventing And Managing Post Traumatic Osteoarthritis In Physically Active Populations: A Consensus Statement Of The Athletic Trainers' Osteoarthritis Consortium. J Athl Train. 52(6): 610-623. DOI: 10.4085/1062-6050-52.2.04.

Friday, August 11, 2017

Don't Drink The Pool Water!


During the last couple of days over National Day, we took a family staycation at the Goodwoodpark Hotel. I ended up spending lots of time in the pool with my two boys as you can see in the picture above. Probably ended up drinking some too.

Not the greatest thing to do if you read what Canadian researchers found when they tracked two public pools for three weeks. Olympic swimmers have admitted doing it and now evidence shows that the rest of the general public are doing it too.

Doing what? Peeing in the swimming pool that's what!

The researchers tracked the concentration of an artificial sweetener, acesulfame potassium (ACE), which is found commonly in processed food and passes through our bodies unaltered. Great for the researchers if you happen to eat processed food and pee in public pools.

By tracking ACE levels, the researchers calculated that swimmers released 75 litres of urine (enough to fill a medium sized dustbin) in the first public pool (830,000 litres, about one-third the size of an Olympic pool).

There was 30 litres of urine in the second public pool, which was around half the size of the first pool over this two week period.

The research team sampled a total 31 different swimming pools and eight hotel jacuzzi hot tubs in two Canadian cities. ACE was present in 100% of the pools and hot tubs!

Number of pool visitors were not monitored, but the results also suggested that urine content in the pool was added several times each day.

If you thought that the pool readings were bad, measurement in the eight jacuzzi hot tubs were much higher. One particular hotel jacuzzi had more than three times ACE levels than the worst swimming pool.

Just so you know, urine is sterile, but the compounds in urine (urea, ammonia and creatinine) can react with pool disinfectants cause eye and respiratory irritation. Long term exposure to these compounds has been linked to asthma.

The results were not surprising as another anonymous survey showed that 19% of adults polled admitted to having urinated in a swimming pool at least once. Professional swimmers have confessed to being among the worst offenders.

Have you ever peed in a swimming pool? Hmmm, let me ask Jo Schooling when he next comes and sees me in the clinic.


References

Blackstock LKJ, Wang W et al (2017). Sweetened Swimming Pools And Hot Tubs. Environ Sci Technol. 4(4): 149-153. DOI: 10.1021/acs.estlett.7b0043.

Wiant C (2012). New Public Survey Reveals Swimmer Hygiene Attitudes And Practices. Int J Aquatic Research Edu. 6(3): Article 4. http://scholarworks.bgsu.edu/ijare/vol6/iss3/4.

Researchers Lindsay Blackstock and Xing Fang Li testing for ACE

Saturday, August 5, 2017

Joseph Schooling At Sports Solutions

Jo at Sports Solutions
For the past few days, our staff were already talking about taking pictures with him when they saw his name booked in for an appointment in our clinic today.

I was treating another patient when Jo arrived, so Jo went to see Aized for his appointment. My next patient was running late so I went to say hello to Jo. Aized said the first question he asked was "Where's Uncle Gino?"

Yes "Uncle Gino" is what Jo still calls me. We used to swim together from 2004 until early 2008 when we were both swimming at the Center of Excellence (COE) under coaches John Dempsey,  Au Yong Kim Moon and Herbert Yu. I used to treat all the swimmers there including Jo.

That was my agreement with head coach John Dempsey. He would allow me to swim with the COE swimmers (while I was still training for triathlons) on the condition that I treat all the swimmers who needed help.

In fact I first treated him at a swim meet in Kuala Lumpur, Malaysia in 2004. Jo used to kick my behind in the pool even when he was nine years young!

Great seeing you today Jo! As Aized said, our pleasure and honor to be treating you when you're home.

Saturday, July 29, 2017

Rhabdomyolysis - The Scary Side Effects Of Exercise


My patient just attended her first spin class with her colleagues. Prior to this, she's been running and wakeboarding for exercise.

The doors to the studio were shut, while the air conditioning was turned off. Other than that, she didn't find pedaling fast on the stationary bike to rhythms of popular music while an instructor shouted motivation too difficult. Neither did she feel she pushed herself too hard. Her legs at the end of the hour long class weren't too sore or wobbly afterwards.

Over the next two days, her legs started throbbing and she came into the clinic to see me. I noticed bruises on her thighs and asked if she knocked them against the stationary bike. She said she didn't recall that happening.

The next day she noticed blood in her urine and checked herself into a hospital where she was warded and after blood and urine tests and was told her she had rhabdomyolysis.

Rhabdomyolysis is rare but can be a life threatening condition often caused by extreme exercise. It occurs when muscles that have been overworked dies and leak their contents into the bloodstream. This strains the kidneys and can cause severe pain.

My patient ended up staying in hospital for a few days before being discharged and has since recovered.

Subsequently I saw an article that documented three unusual cases of rhabdomyolysis, each occurring after a first spin class all treated by the same doctors (Brogan et al, 2017).

The article also described 46 other cases of people developing rhabdomyolysis after a spin class (42 of them in people taking their first spin class). The authors wrote that the condition was rare and not a reason to avoid high intensity exercise.

Another published study found 29 cases admitted to the emergency department between 2010-2014 for exercise induced rhabdomyolysis. Weight lifting, running, cross fit were some of the causes, but the most common cause was spinning classes!

The patients were not unfit, they were in fact being pushed too hard. Since they were not used to the new exercise, they ended up getting really bad muscle trauma.

Remember this next time you try a new exercise. Rhabdomyolysis occurs when you do not give your muscles time to adjust to a new aggressive exercise. When you stress your muscles too much, they tend to break down, releasing contents like myoglobin into your bloodstream which causes brown or tea colored urine, a classic symptom of rhabdomyolysis.

While any intense activity can cause rhabdomyolysis, it almost always strikes the person doing something new. So when you try a new exercise, start moderately first.

Know your limits, don't be pressured by the instructor. You can stop the exercise if you're struggling. Exercise can be dangerous when your body is not prepared for really intense levels.


References

Brogan M, Ledesma R et al (2017). Freebie Rhabdomyolysis: A Public Health Concern, Spin Class-Induced Rhabdomyolysis. AJM. 130(4): 484-487. DOI: 10.106/j.amjmed.2016.11.004.

Cutler TS, DeFilippis EM et al  (2016). Increasing Incidence And Unique Clinical Characteristics Of Spinning-induced Rhabdomyolysis. Clin J Sp Med. 26(5): 429-431. DOI: 10.1097/JSM.0000000000000281.

Here's a picture of a spin class.

Picture from Soulcycle.com

Friday, July 21, 2017

Will The Real Athletes Please Stand Up?

Written by Rachel Wong.

Bella Hadid's picture from Nike 
Just last month, Nike announced that fashion model Bella Hadid would be the face of its previously popular Cortez sneaker, designed in 1972 for runners. If you're an older runner you will remember the Cortez, after all even Forrest Gump used it for his runs.

Picture from Sneaker news
The Cortez is being re-released as a fashion/ lifestyle sneaker. This follows a series fashion models being chosen to front the campaigns of other sportswear brands - Kylie Jenner (Puma), Karlie Kloss (Adidas) and Gisele Bundchen (Under Armour) just to name a few.

Naturally, some professional athletes have picked up on this and commented against this trend.


As a female football player myself, I think it is completely fair that people are upset that the big sporting companies are choosing to hire fashion models (instead of female athletes) to front the advertising campaigns.

It highlights the differences the way marketing is done in female sports. Emphasis is often placed on how good the women look rather than how well they perform, and women's sports are viewed as less prestigious.

Female athletes definitely do not get the same recognition and endorsement opportunities compared to their male counterparts. Not featuring female athletes in major advertising campaigns also perpetuates this problem as the wider population miss out on seeing more female athletes.

After all, most if not all sports brands instantly opt for professional male athletes in their advertising campaigns. Nike previously used Michael Jordan and now Lebron James for its basketball ads while Puma uses Usain Bolt. Why not the same for females?

However, it is not surprising that Nike (and other sporting brands) choose to use these fashion models with their massive social media presence guaranteeing a broader reach. The target audience is also different today - more people are wearing their sneakers as part of a fashion statement and not for exercise. I suppose from a business/ profit making point of view, this is justified.

Occasionally, these companies do get it right. Misty Copeland (ABT ballet dance), Simone Biles (Olympic gymnast), Ronda Rousey (UFC fighter), Annie Thorisdottir (crossfit) and even the USA women's soccer team have broken into the male-dominated world of sports endorsement deals.

Hopefully these big sporting brand names start to understand the value of real-life athletes to their consumers. I feel that the authentic stories of female athletes, rising above the pressures of their circumstances and beating the odds, are so much more powerful than looking good in whatever apparel they are marketing.

Seeing this will definitely attract my attention, and I might end up buying more clothes and shoes I don't need? :) Nike are you listening?


Friday, July 14, 2017

How Healthy Are Elite Athletes?

Taken with my iPhone off my computer from Cyclingnews.com
Compared to most people in the general population yes, elite athletes are very healthy if you read the article by Lemez et al (2015). However, this is a controversial topic that has been debated for years by athletes themselves, coaches and researchers.

I'm sure you've watched the riders at the Tour De France or the athletes competing at the Olympics. At these competitions, they usually rested and focused, look lean, powerful, slick and bursting with energy.

Can you guess how much it took for them to get there? All the grueling training and obsessive dedication required to reach those levels. Is at good for them? Will that pursuit of sustained excellence damage their health?

The answer depends on how you define health and who you compare elite athletes to.The findings from the comprehensive review on mortality and longevity in elite athletes is very clear. Elite athletes fare better than everyone else when it comes to longevity and disease if you define health as "the absence of disease and the capacity to enjoy life and withstand challenges."

That article by Lemaz et al (2015) examined more than 450, 000 athletes and found that elite athletes live four to eight years longer when compared to an equally matched control group in the general population.

Athletes who competed in running, cycling, soccer and swimming (sports with high aerobic demands) had the greatest benefits. Those athletes have lower rates of heart disease, stroke and smoke related cancers. The Tour de France cyclists for example have a 40 percent lower mortality rate than non athletes.

See how skinny he is (taken from Cyclingnews.com)
The other element of health is psychological, the question of enjoyment in life. That is difficult to quantify and answer.

Some studies show that elite athletes have better mental health after their retirement from elite sports. This may be due to the resilience they developed while competing or that exercise itself (trumps medication when treating depression).

However, other studies show comparable rates or even potentially increased risk for mental health issues. This is actually also dependent on the support the elite athletes received during their athletic career and early retirement (Rice et al, 2016).

Similar to an overworked doctor in the emergency department, corporate lawyer or investment banker, elite athletes often put into situations that require them to sacrifice a lot for their mind and body.

The best endurance athletes will push their bodies and their minds as far as humanly possible and this may not be good for them. If not controlled, that very same drive and determination that propels the elite athlete can eventually become harmful.


References

Lemez S, Baker J et al (2015). DO Elite Athletes Live Longer? A Systematic Review Of Mortality And Longevity In Elite Athletes. Sports Med Open. DOI: 10.1186/s40798-015-0024-x.

Rice SM, Purcell R et al (2016). The Mental Health Of Elite Athletes: A Narrative Systematic Review. Sports Med. 46(9): 1333-1353. DOI: 10.1007/s40279-016-0492-2.

Monday, July 10, 2017

Rise In Singapore Teenagers' Use Of Steroids?

"Muscular kids" gym bound at Holland V MRT today
I was a little annoyed with myself when I saw the Channel NewsAsia (CNA) headline on their website this morning.

I actually read about a similar report in the Journal of the American Medical Association (JAMA) just two weeks ago and was going to write about it but I got sick last week and didn't write it yet. So CNA beat me to it. 

Well, my wife told me the journalist (from CNA) does this for a living, whereas I am just a Physiotherapist. So it's already good I have the ideas (but not the time to write it). Grrrrrrr, guess I have to blame it on the fact that our whole family fell sick recently. 

Next time .....

So what does an American journal finding got to do with our local youths?

Well, ever since Holland village has sprouted three gyms, I've noticed a lot more "muscular kids" walking around. Yes, we do have three gyms right here in Holland Village. First F45 set up shop, followed by Ritual gym  and then Virgin Active opened it's doors recently.

Similar to the American article, it may be a widespread misconception that anabolic steroids is only an issue in elite sports. Both the American article and the Channel NewsAsia article suggest that there may be more anabolic steroid users among our teenagers. The Jama article suggest that "most young men using these drugs are doing it to improve their appearance."

Personally, I don't think it's a new problem. I've definitely had cases of teenage bodybuilders and young adults see me in our clinics for sports injuries (and telling me in strict confidence of course) that they've been injecting themselves with anabolic steroids. And that's all I'm gonna say.


Reference

Pope HG Jr, Khalsa JH et al (2017). Body Image Disorders And Abuse Of Anabolic-Andrrogenic Steroids Among Men. JAMA. 317(1): 23-24. DOI: 10.1001/jama.2016.17441

Friday, July 7, 2017

Finding Our Way Back To Fitness

My wife resting and still not feeling quite right after 11 days
It definitely happens to us runners at some point. We get sick, busy or injured. Well, it just happened to my family.

First my wife fell sick last Tuesday. She had a really bad sore throat, viral fever and was feeling really terrible. She thought she could self medicate and had to take two Panadol tablets thrice a day "just to barely function" in her words. I brought her to see the doctor on Thursday and she got better with the stronger medication given by the doctor.

 On Friday, my two and half year old boy woke up with a fever. Oh dear, my wife groaned, she had passed it to him. We had very little sleep that night as his temperature kept spiking during the night. Our helper had to help us throughout the night too. I ended up not going to my usual Saturday morning long bike ride.

Despite not sleeping well, I managed to see patients the whole Saturday. When I got home, my older seven year old boy was running a temperature.

We spend the whole Sunday resting and trying to keep everyone comfortable at home. Thanks to my helper who decided to forgo her off day to help us. Thanks Ami!

I was the last one standing, the "last of the Mohicans" or so I thought. I woke up with a fever at 3 am on Monday morning! Grrrrrrr. I thought I was strong/ healthy enough not to catch the bug but in the end I succumbed.

I ended up not working for the past few days. My wife still hasn't gone in to the clinic. Though she's feeling better, she just doesn't seem quite right. The older boy hasn't gone to school this whole week while the younger boy still gets a fever on and off. Now that was really strong bug that got us down.

A body at rest can and tends to remain at rest. My wife is just lamenting that her fitness is gone, poof just like that! How do we start running or exercising again?

If you've been away from running more than a week, the pool  is great for doing deep water running. If you prefer something land based, you should just try walking first. The goal is to be able feel strong going on a 30 minute walk. If that's too much try 10-15 minutes walking and build from there.

Next, add in some running. Throw in a 10-15 second run after walking  five minutes. If you feel good, you can continue with 10 seconds run / 40 seconds walk for 5-10 mins. Every other day add 3-5 minutes and you'll back on your way.

Your body will definitely tell you if you've done too much during your comeback- you just need to listen to it.

Hmmm, should I go for my long bike ride tomorrow?

Actually, my helper, Ami, is the last one standing, "the last of the Mohicans". Good on you Ami!

Friday, June 30, 2017

How Is Running Good For Your Back?


Many of us runners have heard that running is bad for your knees (although I've put that beyond reasonable doubt here).

Many more of us have been told that running "overloads" our intervertebral discs (IVD) and causes jarring on our spine. And that in turn leads to low back pain.

 I've written about how my own back feels better after running after my accident.

Well, here's more proof that people who regularly run or walk briskly tend to have healthier discs in their spines than people who do not exercise.

This findings refute the myth that running overloads your spine. In fact it shows that running makes the spine sturdier.

The IVD's are located between the vertebrae, acting as cushions to dissipate shock. They contain a thick, sticky fluid that compresses and absorbs pressure during movement to keep your spine in good shape.

Aging, disease and/ or injury can cause the IVD's to degenerate and bulge causing back pain which sometimes can be debilitating.

Check out the evidence provided in the following study. 79 adult men and women were recruited for the study, of which two-thirds of the group were runners for at least five years. The "long distance" group ran more than 30 miles (48 km) a week while the others ran between 12-25 miles a week (19-40 km). The last group rarely exercised at all.

In order to get more information out of the study, the subjects wore accelerometers. Accelerometers measure movement in terms of acceleration forces, or how much power your body is generating when you move.

All the subjects' spines were scanned using MRI, measuring size and liquidity of each disc. In general, the runners' discs were larger and contained more fluid than those who didn't exercise!

Mileage did not matter. The IVD's of the runners who ran less than 30 miles per week were almost identical to the "long distance" group. The authors suggested that compared to moderate mileage, heavy training does not increase disc health nor does it contribute to deterioration.

Here's what's more surprising. The accelerometers showed that walking briskly at about four miles (or 6.4 km) per hour generated enough physical force to bring movement into the range associated with the healthiest IVD's.

Slower walks and standing in place were outside this range. (Now you know why your backs hurt when you stand and not move). Running faster than 5.5 miles (or 8.8 km) per hour were outside the range as well.

The "sweet spot" for IVD's health seem to be between fast walks and gentle jogs.

Things to note. This is a one-time snapshot of the subject's backs. This study cannot prove that running (or exercise) caused the subjects' IVD's to become healthier. Not yet anyway. It shows that people who ran had healthier IVD's.

It also does not tell us whether running (or exercise) can help treat existing disc problems.

My thoughts? The available evidence strongly indicates that IVD's like movement. If you've always been walking and running don't listen to the naysayers. If you have never ran before and want to, perhaps it will help if you start walking briskly first, this will strengthen your IVD's. Progress to run walks (run a little, walk a little) before running to gradually ease your back into it.


Reference

Belavy DL, Quittner MJ, Ridgers N et al (2017). Running Exercise Strengthens The Intervertebral Disc. Scientific Reports. Article No: 45975. DOI: 10.1038/sreo45975.

Friday, June 23, 2017

Please Help My Swollen Knee


My patient sent me the above picture recently asking for help. Her knee became swollen after a recent run. After icing her knee, she decided to use some "imitation/ copy cat" Kinesio Tapes but that didn't resolve the swelling and worse still gave her an allergic reaction.

Knee joint effusions (or swelling) are usually caused by the knee joint producing more synovial fluid due to aggravating factors causing damage to the joint.

As little as 5 ml of fluid can increase pressure within the knee joint. This can be a source of discomfort and concern for the person affected.

It takes a very small volume of fluid in the knee (20-30 mls) to result in biomechanical changes. The quadriceps will be inhibited as a result (meaning you are less willing to use that muscle) and strength decreases rapidly.

It has also been found that swelling in the knee affects joint mechanics particularly during landing tasks. If someone has effusions in the knee, they tend to land with greater ground reaction forces (or impact) and in greater knee extension (or straightening). This results in more forces transmitted to the knee joint and its ligaments. So you can't run and jump quite as well.

When we see knee joint swelling in our clinics, we try to remove the swelling pronto. Flossing the knee joint, using correct Kinesio taping techniques with genuine Kinesio tapes definitely helps.

My favorite is of course aqua based rehabilitation/ deep water running to take advantage of hydrostatic pressure to help with the swelling. This also allows for quadriceps/ hamstrings strengthening early on without additional loading.

If the patient has more severe effusions, we may suggest altering their gait temporarily (we call this pain free walking), using non-steroidal anti inflammatory medication (NSAIDs) or even suggest they get the joint aspirated (I've tried it, it hurts like crazy).

Once the swelling settles, it will quickly and significantly reduce internal pressure in the knee as well as improve quadriceps strength.

We will quickly select rehabilitation exercises to allow specific quadriceps muscle recruitment without increasing intra articular pressure with knee extension. This is usually done in positions of partial knee flexion (20-30 degrees).

Now you know. Come see us in our clinics if your knees are swollen.


References

Hart JM, Pietrosimone B et al (2010). Quadriceps Activation Following Knee Injuries: A Systematic Review. J Athl Trg. 45(1): 87-97. DOI: 10.4085/1062-6050-45.1.87.

Palmieri-Smith RM, Kreinbrink J et al (2007). Quadriceps Inhibition By An Experimental Knee Joint Effusion Affects Knee Joint Mechanics During A Single-Legged Drop Landing. AJSM. 35(8): 1269-1275. DOI://doi.org/0.1177/0363546506296417.

Friday, June 16, 2017

Both Men And Women Equally Unhappy With Their Bodies

Picture by suez92 from Flickr
I do happen to see quite a lot of men and women who are unhappy with their bodies. And lately, some boys and girls too. Previously, I used to treat a lot more women who were unhappy about how their bodies looked so they'll exercise more and get injured in the process. They'll come and see me hoping that I'll make them pain free so they can exercise again.

Their injuries were easy to treat, their mindset much more difficult.

Well, it seems that men are just as likely to be insecure about their looks. I think we're in a cultural shift in terms of the ideal body image. In movies, advertisements and magazines etc, the ideal man is often portrayed and shown to be more muscular than men in the real world.

Don't get me started on the ideal female physique. The fantasy female has a slim hourglass figure with big boobs and a BMI which was in the normal range but close to the underweight category.

A recently published study of 12,716 respondents found that only 28% of men said that they were "extremely satisfied" with their appearance compared to 26% of women.

It is not surprising to note that weight was closely to people's body image. Only 24% of men were extremely satisfied with their weight while 20% women felt extremely satisfied with theirs.

These findings are consistent with the emphasis placed on the importance for being slender for women and appearing athletic and/ or lean for men.

Take note that the subjects had to opt in to take part in the study so this sample size may not be representative of the general population.

And it gets worse for kids. Adolescent boys who were dissatisfied with their body shape were found to be more likely than girls to self criticize and feel distress (Mitchison et al, 2016).

Don't let others tell you how you look affect you. You're stronger than that.


References

Federicks DA,Sandhu G et al (2016). Correlates Of Appearance And Weight Satisfaction In A U.S. National Sample: Personality, Attachment Style, Television Viewing, Self-esteem And Life Satisfaction. Body Image. 17:191-203. DOI: 10.1016/j.bodyim.2016.04.001.

Mitchison D, Hay P et al (2016). Disentangling Body Image: The Relative Associations of Overvaluation, Dissatisfaction, And Preoccupation With Psychological distress And Eating Disorders In Male And Female Adolescents. Int J Eating Disorders. 50(2): 118-126. DOI: 10.1002.eat.22592.

Sunday, June 11, 2017

Is Running On A Treadmill More Difficult Than Running Outside?


I've had patients travelling this past couple of weeks during their kid's school holidays. The only time they could run was on a treadmill in the hotel. A few of them have asked me why they found running on a treadmill more tiring than on the road or track. 

I thought this was strange as running on a treadmill should not be more difficult than running outside and looked it up. 

And true enough, I found an article in which runners were asked to run on a track and then asked to rate how difficult the exercise felt. They then went on a treadmill without a display unit of the speed they were running and told to set the treadmill at the same pace they thought they had just ran. Almost all the runners chose a speed that was much slower. 

Researchers have found that for most people, running biomechanics are similar whether running on a treadmill or outside (Riley et al 2008).

In fact, running on a treadmill is less jarring than running on the ground outside. A 2014 study (Kaplan et al, 2014) showed that we strike the ground with about 200 percent of our body weight while running on an outside track. This was reduced to 175 percent of our body weight when running on a treadmill. 

Evidence suggest that the hard work associated with treadmill running is psychological. Many studies show that people experience less fatigue, more vitality and greater pleasure waling outside compared to walking on a treadmill. 

Personally I feel it is definitely nicer to exercise outdoors. I don't like running on the treadmill too much. I'd much prefer running outdoors any time. I feel like a caged hamster going on and on in a wheel when I'm running on a treadmill. 

Picture from giphy
However, after my accident, I'm very happy just being able to do any exercise. A run is a run, whether outdoors or on a treadmill.


References

Kaplan Y, Barak Y et al (2014). Referent Body Weight Values In Over Ground Walking, Over Ground Jogging, Treadmill Jogging, And Ellipticall Exercise. Gait Posture. 39(1): 558-562. DOI: 10.1016./j.gaitpost.2013.09.004.

Kong PW, Koh TM et al (2012). Unmatched Perception Of Speed When Running Overground And On A Treadmill. Gait Posture. 36(1): 46-48. DOI: 10.1016./j.gaitpost.2012.01.001.

Riley PO, Dicharry J et al (2008). A Kinematics And Kinetic Comparison Of Overground And Treadmill Running. Med Sci Sports Ex. 40(6): 1093-1100. DOI: 10.1249/ MSS.0b013e3181677530.

Thompson CJ, Boddy K (2009). Does Participating In Physical Activity In Outdoor Natural Environments Have A greater Effect On Physical And Mental Wellbeing Than Physical Activity Indoors? A Systematic Review. Environ Sci Technol. $5(5): 1761-1772. DOI: 10.1021/es102947t.

Monday, June 5, 2017

Should I Be Using A Standing Desk?

Now, that's a different standing desk. By Liz Henry from Flickr
Sitting kills. That's the headline many of you would have seem or read in the last few years. You've also read or heard that sitting is the new smoking. And if you've been following our blog, I've written before that despite exercising a lot, if you sit too much at work, you can be what is known as an active couch potato. Worse still, all that sitting can negate the benefits of your exercise.

Well fortunately for me, I hardly get to sit much when I'm working in the clinic.

Many of my patients have asked about the benefits of a standing desk. I even found a picture (below) of former British Prime Minister Winston Churchill working on his slanted standing desk.
Kurt Hutton/picture post via Getty
Standing desks have been suggested as an alternative to the ills of sitting. And there's studies to show that working upright (at a standing desk) can help correct your posture and tone your stomach and legs without compromising your focus.

And in kids, standing desks seems to increase their energy levels and reduce hunger.

My take on standing desks? I've seen many of my patients go straight from sitting to a standing desk get different problems. Being unaccustomed on their feet all day long poses new risks. It can inhibit proper circulation and add additional pressure to your hips, legs and lower back. Sort of like jumping from the frying pan into the fire if you ask me.

And unfortunately, research shows that sitting once or twice throughout your work day will not offer you enough relief. So don't switch to a standing desk if you've been sitting all day straight away, make sure you gradually phase it in.

What are the alternatives? I prefer the stability ball or better still the saddle stool with adjustable height so that you can perch on it if you're not quite used to standing yet.
Our clinic's saddle stool
There's also the desk cycle, though I definitely haven't tried it yet.
Desk cycle
References

Commiassaris DA, Konemann R et al (2014). Effects Of A Standing And Three Dynamic Workstations On Computer Task Performance And Cognitive Function Tests. Appl Ergon. 45(6): 1570-1578. DOI: 10.1016/j.apergo.2014.05.003.

Garcia MG, Laubil T and Martin BJ (2015). Long-term Muscle Fatigue After Standing Work. Human Ftr and Ergo Society. 57(7): 1162-1173. DOI: 10.1177/0018720815590293.

Monday, May 29, 2017

Steroid Injection Not Better Than Placebo For Low Back Pain

Picture by Army Medicine from Flickr
It seems like another of my patients has been asked if he wanted a cortisone (or corticosteroid) injection for his low back pain after I wrote about my shoulder pain patient last week who was asked by another doctor to get a steroid injection.

Evidence that they (cortisone or corticosteroid injections) work no better than placebo is mounting though.

The article referenced below is a systematic review. A systematic review is a computer aided search for all randomized and clinical controlled trials, meaning it's top of the line in terms of quality.

Researchers pooled data together from 30 placebo controlled studies of epidural steroid injections for radiculopathy (back pain that radiates to legs) and eight studies for spinal stenosis (back/ neck pain caused by narrowing of the spinal canal).

For radiculopathy, the steroid injections provided only short term relief. Over time, they were not more effective compared to placebo injections. They also did not reduce the need for surgery later for patients with more severe conditions.

The pooled data was similar for spinal stenosis.There was only some moderate temporary pain relief after the corticosteroid injections. There were no differences between steroid injections and placebo injections in pain intensity or functional ability lasting six weeks or longer after the injections.

The authors did note that some studies did not have many subjects while others had shortcomings their methodology.

The researcher in charge also suggested that there was probably some financial motivation to carry on using steroid injections despite the lack of evidence for its effectiveness. There is also a worry among professional societies (for doctors) due to implications for insurance coverage.

Other mentioned less selfish reasons is that doctors see their patients in horrible pain and concede that they do get some pain relief after the injections.

Please come to our clinics if you need help with your low back pain. We definitely do not give steroid injections.


Reference

Chou R, Friedly J et al (2015). Epidural Corticosteroid Injections For Radiculopathy And Spinal Stenosis: A Systematic Review And Meta-analysis. Ann Intern Med. 163(5): 373-381. DOI: 10.7326/M15-0934.

Sunday, May 21, 2017

Shoulder Pain From Swimming? Treat Your Neck

Yes, your shoulder pain is coming from your neck
I had a really interesting case this past week. A patient who's an elite swimmer comes in to our clinic complaining of shoulder pain.

An ultra sound scan and MRI that was done confirms the diagnosis of shoulder subacromial impingement (usually the tendon of the supraspinatus muscle gets irritated from hand above head activities under the acromium).

The doctor my patient saw the the Singapore Sports Institute suggested a steroid (or cortisone) injection to "solve the problem".

R shoulder impingement
Well, the Physiotherapists reading this must be thinking "yeah, what's the big deal". All elite swimmers (or athletes involved with overhead sports like badminton, tennis etc) always get shoulder pain from subacromial impingement at some point of other in their sporting career.

Well, here's the thing, I got the swimmer better just be treating the swimmer's neck. This swimmer did not have any neck pain or signs of nerve root irritation.

I've seen other cases of shoulder impingement when the patient had obvious clues suggesting it was the neck and/ or nerve root irritation causing the shoulder impingement.

This swimmer did not have any neck pain or nerve root irritation signs. The patient did have a forward head posture which can contribute to a C5 nerve root involvement.

Similar to the article referenced below, the swimmer got better very quickly just by cervical retraction, as taught by Gwen Jull. Of course treatment also included other things and not just cervical retraction.

My swimmer went back to full training in three days with no recurrence of symptoms. Good thing my patient said no to the steroid or cortisone injection.

Reference

Pheasant S (2016). Cervical Contribution To Functional Shoulder Impingement: Two Case Reports. Int J Sports Phys Ther. 1196): 980-991.

Saturday, May 13, 2017

Rachel Plays Her Part Helping VJC Win 5th Straight Football Title


On Sunday night (7/5/17), my colleague Rachel asked me if she could leave work early on Tuesday 10/5/17. She wanted to watched her alma mater play in the 'A' division girls football final against Meridian Junior College.

Rachel was top scorer before in her time at Victoria Junior College (VJC) when she herself represented VJC. As I wrote previously, she scored a hat trick when VJC beat my alma mater's team 10-1 in the semi finals of the same tournament eight years ago.

When I introduced her to a physical education teacher from the losing school, he immediately remembered the trashing our school received and he was in awe of her. Still famous as ever eight years on. Well done Rachel!

Of course she could go! She had been volunteering her time (with the clinic's blessings) most Wednesday's afternoons at VJC since the beginning of the year.

On days before a match, if you come to our Holland Village clinic you might be lulled into thinking VJC was near our  clinic (and not in Marine Parade) or that our clinic was a mini VJC gathering place.

Definitely businesses near our clinic like Sunday Folks and The Daily Scoop have benefited when the students come for treatment as they go there after treatment.

So congratulations to VJC for the fifth consecutive football title and Rachel Wong for a job well done!
Rachel with the victorious team.
Note: Rachel also treats students competing in other sports and not just the girls from football. So perhaps next year we'll see more VJC students in our clinic this time of the year?

Saturday, May 6, 2017

Eccentric Exercises

Ting Jun and Rachel going down stairs outside our clinic
I was talking with a patient of mine earlier who exercised by climbing up and going down the stairs at his 40 storey flat while carrying a 16 kg backpack. He knew about my past results climbing stairs and wanted to know why walking down a flight of stairs seems to be more effective at building his muscle strength than walking up the same flight of stairs.

Going down the stairs with his 16 kg backpack meant he had to really control his step and lower himself down slowly rather than just letting himself go. This meant that he was doing an eccentric exercise.

Say you want to train your biceps (arm muscles). When you bring the dumbbell up, the muscle is shortening, that is also known as a concentric muscle action. If you lower the dumbbell slowly (which is more difficult), the muscle is lengthening or an eccentric muscle action.

Eccentric exercises are more demanding on the muscles and fatigues then far more than concentrically. It also damages (or breaks down the muscle) to a greater extent, so there is greater stimulation and subsequent growth.

Try this if you want get better leg strength in a shorter time. Bend your legs more deeply when going down stairs of hills. Your legs will be sore from DOMs or delayed onset of muscle soreness. Once your muscles recover (after a few days), they'll be stronger and it will require much more eccentric exercises to get the same effect.

In fact, this was exactly what researchers found in a group of elderly men with chronic heart failure. Going down stairs appeared to be easier and more pleasant compared to the climbing stairs which the subjects found to be more demanding.

Changes in muscle strength were similar or even greater when going down stairs compared to going up stairs after six weeks of training.

To put this into practice, try bending your legs more deeply when going down stairs or slopes, lower your body more slowly doing push ups or pull ups. You'll be amazed at the results ..... after recovering from  the soreness.


Reference

Theodoru AA, Panayiotou G et al (2013). Stair Descending Exercise Increases Muscle Strength In Elderly Males With Chronic Heart Failure. BMC Res Notes. 6:87. DOI: 10.1186/1756-005-6-87.

Sunday, April 30, 2017

Retired Pharmacist Comes To Kinesio Taping Course

I forgot to mention yesterday that we have Mrs Chong, who's a grandmother (and trained pharmacist) at 73 years young attending the course with her daughter Alyce.
Mrs Chong in action
Mrs Chong's granddaughter (and Alyce's daughter) competes in gymnastics and equestrian and both of them decided to come and attend the course together (to bond) and to be able to tape competently for their granddaughter and daughter respectively. Now that's real love.

By the way, Mrs Chong also paints, takes many other classes and still takes exams to keep her pharmacist license.

I really respect Mrs Chong's attitude. Note to self - never stop learning.

Back to the course and the day started with some questions on whether participants left their tape on overnight (and many did) and what they felt. None reported any adverse reactions

We continued Day 2 of the course learning all about the six different corrective techniques in Kinesio Taping. Mechanical correction, fascia correction, space correction etc.

A few of the participants brought along different brands of tape to try and none (according to the participants) matched the high standards of the Kinesio FP tape.

Check out the "Heroll" tape



Here are some pictures from the course.

Theresa and her amazing technicolor dream tapes
Both the netball coaches admiring a Team Singapore attire?
Group picture of the participants

Saturday, April 29, 2017

Explaining About The Homunculus At The Kinesio Taping Course

Sports Solutions hosted the Kinesio Taping Level 1-2 course today and no surprises, the course was fully subscribed.

It was bright sunshine after the early morning storm and the day started with explaining the science and rationale behind how Kinesio Taping works.

After my own learning journey from the Anatomy Train courses, lessons from Andrew Hutton, Flossband (with Sven Kruse) and David Butler, I can definitely explain and teach the course better. Well, I'd better because I had to explain what the homunculus was to the class.


Teaching the homunculus
Of course we spent some time going through anatomy and surface landmarks.

Palpating for C1 after finding the mastoid process
Finally after all the talking, it was time to tape.

All eyes and ears
Stay tuned for Level 2 tomorrow.

Sunday, April 23, 2017

Don't Ignore That Ankle Sprain

Now that's a nasty ankle sprain
We've seen quite a few cases of ankle sprains in our clinics recently. Most of these patients are young school athletes representing their school or participating in sports.

We've always managed to get our patients playing/ competing again quite quickly. Even ankle cases that were deemed serious, we've managed to get them up and running so quickly that their parents/ coaches were pleasantly surprised.

Hence I was surprised to read that ankle even if sprained only once but not treated properly can have lifelong consequences. Especially if the sprains keep recurring.

In the study referenced below, the researchers had students who had chronic ankle instability (caused by ankle sprains) wear a pedometer for a week. Their steps taken were compared with a control group of students who had normal ankles. Gender, BMI and general health were the variables controlled in both groups.

Turns out that the students with chronic ankle instability moved significantly less than the other group. They took about 2000 steps fewer on average.

The researchers were concerned with the obvious decrease in step count as this decrease may be secondary to other functional limitations. If this decrease in physical activity continues for an extended period,it may lead to other more substantial heal risks.

Next time you sprain your ankle, make sure you get it checked and treated properly, even if it seems to be mostly healed as it can lead to lifelong consequences.

Reference

Hubbard-Turner T and Turner MJ (2015). Physical Activity Levels In College Students With Chronic Ankle Instability. J Athl Trg. 50(7): 742-747. DOI: 10.4085/1062-6050-50.3.05.


Note to self and my colleagues: be wary even of a simple ankle sprain

Friday, April 14, 2017

Is It Necessary To Cool Down After Exercise?

Stretching after a run in the rain
Back when I was working at the old National Stadium, I'll very often before work or during lunch time run on the track or grass surrounding the track.  Straight after I was done, I'll head right in to the clinic. A person walking past commented how I could do that.

I said I just stopped after running and am heading for the showers as my next patient was due soon. He said I should be doing a cool down after such a hard run.

Well, I was in a hurry to get ready for my patient. I'm sure the patient wouldn't like a sweaty, dripping physiotherapist treating him.

Looking back since primary school, I recall our physical education teachers telling us that we need to cool down after exercise and especially after a race/ competition.

Personal trainers will tell their clients that slowing to a jog and/ or lessening the intensity of the workout followed by stretching to transition out of the exercise session so as to prevent muscle soreness and improve recovery.

Some exercise machines in the gym automatically include a cool down period. After your work out time that you keyed in, the machine automatically reduces the workload and continues for five minutes so you can cool down.

I tried looking for scientific evidence regarding that and it seems none of those beliefs were true.

A study had subjects do a strenuous one time session of forward lunges while holding barbells. This is certain to make untrained people extremely sore due to DOMs over the next few days.

Some of the subjects warmed up before by cycling 20 mins gently. Others didn't warm up but did a cool down after the lunges with a similar 20 mins of gentle stationary bike riding. The rest of the group just did the lunges without warm up or cool down.

The next day, the subjects who warmed up had the least pain while there those who did the cool down and the control group had similar pain. Cooling down brought no benefits to the group.

Two other studies I found on professional football players performing cool down versus no cool down yielded the same result. Measures of performance, flexibility and muscle soreness were similar.

One valid reason to cool down after exercise is to prevent venous pooling (or build up of blood in your veins) after vigorous exercise. Blood vessels in your legs expand during prolonged vigorous exercise, allowing more blood to move through them to supply oxygen. When you stop exercise abruptly, the blood stays in your lower body. This can lead to dizziness or even fainting.

It's easy to avoid venous pooling, just keep walking for a few minutes at the end of your workout/ race and you'll maintain normal blood supply to the brain. Would you consider that as a cool down?

So, there's no real published research showing any negative effect if you don't cool down. If you are used to performing a cool down after your exercise, you can definitely carry on. If you don't feel like it, then you probably don't have too.

Unless future research shows otherwise, don't worry if your friend/ trainer/ coach tells you that you need to cool down after exercise.

References

Olsen O, Sjohaug M et al (2012). The Effect Of Warm-up And Cool Down Exercise On Delayed Onset Muscle Soreness In The Quadriceps Muscle: A Randomized Controlled Trial. J Human Kinetics. 35: 59-68. DOI: 10.2478/v10078-012-0079-4.

Rey E Lago-Penas C et al (2012). The Effect Of Immediate Post-training Active And Passive Recovery Interventions On Anaerobic Performance And Lower Limb Flexibility In Professional Soccer Players. J Human Kinetics. 31: 121-129. DOI: 10.2478/v10078-012-0013-9.

Rey E Lago-Penas C et al (2012). The Effect of Recovery Strategies On Contractile Properties Using Tensiomyography And Perceived Muscle Soreness In Professional Soccer Players. J Strength Cond Res. 26(11): 3081-3088.