Sunday, November 27, 2022

Will Marathon Running Hurt Your Back?

A patient who came in earlier this week asked if I still did any running. He had signed up for the Singapore marathon early next month and was worried that he may hurt his back taking part. He wanted my views since he had heard about my compression fracture (pictured below) as he had the occasional back ache.

Spot my compression fracture at L1?
I shared with him what I did and showed him the evidence that running definitely did help my low back pain. Of course I am not running as fast nor as long as when I used to race. I hardly run more than 7 km at a go now. Mainly due to a lack of time rather than an inability to.

I also shared with him other evidence of how researchers studied a group of runners who had never attempted a marathon before. 

28 runners (14 males, 14 females) with an average age of 30 signed up for their first marathon and were recruited by researchers. They went for a high resolution MRI screening 16 weeks before (time period 1) the race and another 2 weeks after the race (time period 2). 

The scans were subsequently assessed by senior musculoskeletal radiologists. At time period 1, 61 percent (17 out of the 28) of the runners had disc degeneration at mainly L4-L5 and L5-S1 levels. However, none of them had any back pain nor other symptoms.

Subsequently, the subjects underwent a 16 week training program. 21 out of the 28 runners completed both the 500 miles (800km) training and the race. The other 7 did not complete the training nor started the race. None of them dropped out due to spine related issues.

During time period 2, the researchers found no progression (or worsening) in those who had the disc degeneration in the second MRI. In fact, there was a regression in 2 out of 8 patients with bone marrow oedema in their sacroiliac joints (SIJ). Meaning their scans improved!

The only 'blemish' was one participant who had a small increase in the size of a subcondral cyst. However, this participant remained pain free.

Still thinking about doing that first marathon? Well, you know that running will not wear out your knees nor worsen your back. In fact your joints and connective tissues love movement. Movement lubricates your joints and hydates your connective tissues. So go run that marathon!


Horga LM, Henckel J, Fotiadou A et al (2021). What Happens To The Lower Lumbar Spine After Marathon Running: A 3.0T MRI Study Of 21 First-time Marathoners. Skeletal Radiol. 51: 971-980. DOI: 10.1007/s00256-021-03906-5.

My L1 is 'collapsed' compared to above and below

X-ray of my back 2 weeks after my first accident above.

Sunday, November 20, 2022

Is Yoga Helpful For Low Back Pain?

Please let me be clear, I have nothing against anyone doing yoga or any yoga instructors. I'm just sharing what I read from a published Cochrane review.

This latest Cochrane review that was just published 2 days ago, evaluated whether yoga was beneficial or harmful for treatment of non specific low back pain. Review articles from the Cochrane Database of Systematic Reviews are highly respected and trusted.

The review wanted to find out if yoga helps improve function (getting dressed, walking or housework), quality of life and pain associated with low back pain. Medical databases searched for randomized controlled trials of yoga compared to sham (fake) yoga, no treatment, any other treatment and yoga added to other treatment.

Altogether 21 trials with 2223 participants (mostly women in their 40's or 50's) were found. 10 trials from USA, 5 from India, 2 form UK and 1 each from Crotia, Germany, Sweden and Turkey.

10 studies compared yoga to no exercise control group which received usual education and were put on a waiting list for yoga. 6 studies compared yoga to back-focused exercise or similar core exercise programs.  5 studies compared yoga, no exercise and qigong.

At 3 months, there was low to moderate evidence that yoga was slightly better than no exercise in improving back function and pain, although the difference were not sufficiently important to the person with low back pain

There was low quality evidence for better clinical improvement with yoga while there was moderate quality evidence for a slight improvement in both physical (able to be active) and mental (emotional problems) quality of life.  Evidence was of very low quality for helping depression. In addition there was moderate quality evidence that there was little or no difference between yoga and other types of exercise in improving back function and pain.

Increased low back pain was the most commonly reported 'harmful' reaction and there were no reported cases of serious side effects. There was low quality evidence that the risk of harm was higher with yoga than no exercise and back-focused exercise.

No studies comparing yoga to sham yoga were found, so there is no evidence how yoga would affect low back pain if people did not know they were doing yoga. All the participants knew they were doing yoga and this may influence their interpretation of whether their back pain has changed.

There you have it, quite different from what you have been told, heard or read. Our goal is to help patients confidently take up different movement, postures, physical activity, social and work engagement so you can can a healthy and pain free life.

There are free educational resources to support these processes if you do have low back pain and have not seen us in our clinics.

You can watch this Youtube video or visit this site for more details. This will help reduce stress and build self sufficiency for you to better self manage your LBP and make better informed choices about your care.

Our spine is strong, robust and adaptable. A campaign to change this may encounter resistance even in the physiotherapy and ergonomic professions as their business model may not be in line with what we now know to be best practice for managing low back pain.

So here's my take, whether it's yogapilatesstationary cycling or any exercise, it is your choice, as long as you keep doing it consistently, it will help your low back pain. Find an exercise you enjoy and keep at it. 


Wieland LS, Skoetz N, Pilkington K et al (2022). Yoga For Chronic Non-specific Low Back Pain. Cochrane Database of Systematic Reviews. Issue 11. Art. No : CD010671. DOI: 10.1002/1465.CD010671

Sunday, November 13, 2022

Should You Be Taking Creatine?

I remember friends talking about creatine making them 'fly' while racing, back in the late 1990's, when I was still competing. Now, it seems that taking creatine is in vogue again after a few patients asked for my opinion about whether creatine is performance enhancing.

Creatine use back in the 90's was popular because it actually did what was claimed on the container (unlike many other supplements). It definitely changed how sports nutrition was viewed.

Creatine is a natural compound in our body produced from amino acids. It is also found in red meat and some fish. In our muscles, it is called phosphocreatine (or free creatine) where it is necessary for enabling movement and exercise. Phosphocreatine is responsible for quickly restoring ATP levels in muscles, which functions as the 'energy currency' for cells. 

ATP is broken down (or used) when our muscles contract during exercise and other activities. Phosphocreatine provides a qiuck pool of energy to allow quick restoration of ATP, which is fuel especially for high intensity exercise. Since creatine exist only in small amounts in the body, it is enough to fuel about 10 seconds of intense effort or all out sprint. Hence this is the 'free creatine' energy we all have in our bodies when needed for that 10 seconds worth of intense exercise.

Note that the body can also produce ATP from carbohydrates and fat, but it is a relatively slow process.

How creatine works is that it is able to produce strength gains because it enhances the short term, high intensity energy pathway in muscles called the phospho-creatine (PC) system. 

If the PC system is enhanced, it allows our muscle fibers to contract vigorously for longer periods allowing more intense loading and fatigue for the muscles. After the muscles break down, it produces greater repair and growth stimulus with adequate rest and nutrition This ultimately results in greater strength gains.

Taking creatine supplements can increase creatine stores in the body by up to 30 percent. Many types of creatine are available, the cheapest and most researched being creatine monohydrate. Bear in mind that the pricier creatine hydrochloride and ethyl ester have not been proven to be superior.

Many people who take creatine start with a loading phase of 20-30 grams per day (for up to 7 days) to saturate stores quickly, leading to a rapid increase in muscle stores of creatine. Subsequently, they take 3-5 grams daily to maintain levels.

Those who choose not to load will consume 3-5 grams daily. Research shows this is just as effective and it will take up to a month to maximise stores this way before it has an effect. 

A known side effect of consuming creatine is weight gain since creatine causes water retention in your muscles. This weight gain varies between 1-3 kg and not everyone who takes creatine experiences it. It can also cause mild stomach discomfort when large doses are taken. Long term supplementation with high doses have been investigated and shown to be safe in healthy subjects (Kreider et al, 2017).

Creatine supplementation is extremely popular with sprinters, strength and power athletes, especially when their events last for less than 30 seconds. It increases muscle mass and strength during weight training as well as improving performance during competition. 

Since body weight is not as important in sprints, weight and power lifting, athletes from these sports can benefit as increases in performance more than compensates for the increase in body weight.

Those who participate in sports like soccer, basketball or hockey when intermittent short bursts of high intensity sprints and jumps are required will benefit with creatine supplementation. Specific tests where power output and speed are improved have been shown in athletes in such sports (Ramirez- Campillo et al, 2016).

What about endurance sports? In ultra events, the need for high intensity surges or bursts are less frequent, so as exercise duration increases, benefits of creatine reduces. Research on endurance sports are mixed though most show no benefit. An increase in body weight from consuming creatine may increase energy requirements and require greater power output.  

I was asked why I took creatine supplements since research does not show much support when I used to race triathlons. I mainly raced the Olympic distance (1.5km swim, 40km bike, 10 km run) triathlons where fellow competitiors may surge on the climbs during the bike or run section to breakaway or get a gap. As such, we do need to respond to such high intensity surges otherwise the race may be over if you get dropped

This was the main reason I thought taking creatine may help, since I needed to be able to sprint intermittently during my event, especially up slopes or near the end of a race. Studies that investigate cycling using stationary bikes where slight increases in body weight may not affect performances show benefits from taking creatine. This may occur in similar scenarios that I mentioned in a climb during a race or a sprint finish where there is a need for higher power output or speed (Murphy et al, 2005). 

At these times, phosphocreatine contribute heaps to energy production, so an increase in creatine stores may be helpful. Bear in mind that the increase in body weight that sometime accompanies creatine supplementation is sufficient to cancel out the benefits. Especially in a hilly or longer race.

Utimately I stopped taking creatine supplements after 3 months because I did put on 1-2 kg of body weight. In addition I was not sure if it helped my ability to sprint and close gaps. I naturally have a good amount of Type IIa and IIb fast twitch muscle fibers already so the weight gain was not justified.

If you, like my patients, have heard good results about creatine and want to try it, bear in mind the scenarios that I mentioned.


Kreider B, Kalman DS, Antonio J (2017). International Society Of Sports Nutrition Position Stand: Safety And Efficacy Of Creatine Supplementation In Exercise, Sport, And Medicine. J Int Soc Sp Nutr. 14:18. DOI: 10.1186/s12970-017-0173-z

Murphy AJ, Watsford ML, Coutts AJ et al (2005). Effects Of Creatine Supplementation On Aerobic Power And Cardiovascular Structure And Function. J Sci Med Sp. 8(3): 305-313. DOI: 10.1016/s1440-2440(05)80041-6.

Ramirez-Campillo R, Gonzalez-Jurado R, Martinez C et al (2016). Effects Of Plyometric Training And Creatine Supplementation On Maximal-intensity Exercise And Endurance In Female Soccer Players. J Sp Med Sci. 19(8): 682-687. DOI: 10.1016/j.jsams.2015.005. DOI: 10.1016/j.jsams.2015.10.005

Sunday, November 6, 2022

Only Some Runners Ran Faster Using Carbon Plated Shoes

Alphafly (L) and Vaporfly from
Ever since Kipchoge ran a sub-2 hour marathon in the carbon plated Nike Alphafly in 2019, every single of my patients who participate in running races want to race in a pair too. Back then, those super shoes were really hard to get a hold of, for almost a year. If you did get your hands on a pair, they cost a bomb too.

Now that these super shoes are more easily available (since many other brands other than Nike also make carbon plated shoes), is it worth splurging on them? Especially if you're trying to clock a personal best timing in your next race.

How does the original Nike super shoe (the Vaporfly) work? There are 2 novel components to this question. First, the super thick cushioned midsole Nike calls ZoomX. This new foam is super light, 31 millimeters high at the heel, which is 50 percent thicker than comparable shoes without being heavier. You can squish it and it springs back to shape quickly. This means it returns all the energy you applied to squish it. 

Next is the curved carbon fiber plate inside the midsole (pictured above). It is thought that the carbon fiber plate(s) acts like a spring, bending as your foot lands and then catapulting you forward as it springs back into position. This helps running economy (reduces energy expenditure) so you can run faster.

Ever since Nike launched their Vaporfly in 2017, which has since been updated a few times, there have been calls and debates to have the shoe disallowed in competition. Opposers have labelled the shoe as technical 'doping'. When subsequent studies showed that these Nike shoes gave up to a 4 percent advantage (Barnes and Kilding, 2019), other runners were obviously upset

Especially after two Nike sponsored runners in the United States used the prototype version at the 2016 Olympic trials (women's 1st and 3rd places) and qualified for the Olympics.

Shalaya Kipp felt that the prototype Vaporfly's kept her training partner, Kara Goucher (4th place), off the Olympic team after signing up with Skechers. She left Nike in 2014 beacause of the infamous Alberto Salazar "Oregon project". Had Goucher stayed with Nike, she may have qualified for her third Olympics in 2016. At the actual 2016 Olympics, the top 3 male finishers all wore the same Nike prototype shoe.

In fact Nike scored a major coup when they offered all other runners who qualified in the 2020 USA marathon Olympic trials a pair of the Alphafly's to level the playing field.

Before you buy a pair of carbon plated shoes, consider the following study. It was published just last month looking at 96 runners using 2 different prototypes of carbon plated  shoes. The shoes differed only by the forefoot bending stiffness. The runners were first assessed for their VO2 max and maximum aerobic speed. Running economy and stride kinematics were also recorded during the trials. 

The researchers did not find any significant difference in running economy between the 2 different shoe stiffness for the group as a whole. Some runners' running economy improved when the carbon fiber plate was stiffer while in other runners, their running economy deteriorated. To be more specific, the faster runners took advantage of the increased stiffness (carbon fiber plates) while the slower runners did not.

The authors emphasized the importance of individual response to using carbon fiber plates to enhance running performance is runner specific. 

For now, the carbon plates remain street legal for us mortal runners in competition. If you do get them, remember to break them in with a few runs instead of just saving them for race day. The midsole thickness definitely makes your foot more unstable especially when going around sharp corners or while making a u-turn in an out and back route.


BarnesKR and Kilding AE(2019). A Randomized Crossover Study Investigating The Running Economy Of Highly-Trained Male And Female Distance Runners In Marathon Racing Shoes Versus Track Spikes. Sports Med. 49(2): 331-342. DOI: 10.1007/s40279-018-1012-3.

Beck ON, Golyski PR and Sawiki GS (2020). Adder Carbon Fiber To Shoe Soles May Not Improve Running Economy: A Muscle-level Explanation. Sci Rep. 10: 17154. DOI: 10.1038/s41598-020-74097-7

Chollet M, Michlet S, Horvais N et al (2022). Individual Physiological Responses To Changes In Shoe Bending Stiffness: A Cluster Analysis Study On 96 Runners. Eur J Appl Physiol. DOI: 10.1007/s00421-022-05060-9

Sunday, October 30, 2022

Is It Really Your Piriformis?

A patient came in to our clinic this week complaining of deep buttock pain and sciatica - pain along the path of the sciatic nerve, the largest nerve in our bodies.
The sciatic nerve starts from the lower back through the hips and buttock down the back of our leg. See picture above.

The sciatic nerve usually travels from within the hip to the deep gluteal space (buttocks) via the greater sciatic notch. It's pathway is most commonly beneath the piriformis muscle (90 percent). Sometimes it goes through the piriformis muscle (7 percent). See picture below.

Right Piriformis muscle and the sciatic nerve

Because of this, the pirifomis muscle is often blamed to be the cause of the pain, which is known as piriformis syndrome.
The nerve then travels over the obturator internus muscle and gemellus superior, inferior muscles (gemellei) to exit that area. Picture above.

The sciatic nerve can get encroached or irritated by the piriformis and adjacent structures in that deep gluteal space which may result in pain at the area of irritation or along the path of the sciatic nerve - this is true sciatica pain.

After assessing my patient, there was no pain nor tenderness in her piriformis. Instead, her obturator internus reproduced her buttock pain. 

Coincidently, I was fortunate to have read a recently published article exploring the relationship of the sciatic nerve and the deep hip external rotator muscles in the deep gluteal space (Balius et al 2022).

The authors recruited 58 healthy volunteers, 30 males and 28 females with an average age of 20.4 years plus or minus 7 years using real time ultrasound to quantify nerve action.

The sciatic nerve was found to be compressed (and moved forward and laterally) during passive hip internal rotation and isometric external rotation contraction (obturator internus and gemelli muscles working). Not the piriformis muscle, which the authors wrote were often over diagnosed.

During passive hip external rotation and isometric contraction of internal hip rotators, the sciatic nerve moved back into place and medially.

The obturator internal-gemellus syndrome may be a more accurate term than piriformis syndrome for my patient. 

Interestingly, the same lead author, Balius and colleagues, published an earlier article in 2018 where they studied 6 fresh cadavers and 31 healthy volunteers. This study revealed the presence of connective tissue (or fascia) attaching the sciatic nerve to the obturator internus-gemellus tendons. The sciatic nerve was also affected similarly in the cadavers and subjects during passive hip internal rotation. 

This newer study (Balius et al, 2022) provides further evidence that stretch or contraction of the obturator internus-gemellei complex will create some compression of the sciatic nerve at this level in the deep gluteal space. Definitely worth considering for those with buttock pain and sciatica.

The next time you have buttock pain or sciatica and the health practitioner treating you tells you that you have piriformis syndrome you may suggest it's not always the piriformis ;)


Balius R, Pujol M, Perez-Cuenca D et al (2022). Sciatic Nerve Movements In the Deep Gluteal Space During Hip Rotations Manuevers. Clinical Anatomy. 35(4): 482-491. DOI: 10.1002/ca.23828

Balius R, Sussin A, Morros C et al (2018). Gamellei-obturator Complex In the Deep Gluteal Space: An Anatomic And Dynamic Study. Skeletal Radiol. 47: 763-770. DOI: 10.1007/s00256-017-2831-2

Monday, October 24, 2022

The Big Picture

I was away on holiday with my family last week and I had some time to think. Instead of a regular post, I came up with the following questions and some answers.

My main questions were, "How can I make myself better as a physiotherapist?", "How can I ensure that all the physios in my team get better?", "How can I make our clinics better for our patients?"

My thoughts were that I always have to keep up with the research that's out there, the solid ones of course. I keep my mind open to new ways of reading the human body and what is "normal". I look out for courses to upgrade my skills. These answers were just some of ones that came to mind.

I will of course be consulting with Aized, Megan, Byron, and Hui Meng for their thoughts of my questions. I'm curious to hear how they would answer my many questions. That's why I value my team. We see the world through different lenses, so I learn from their views too.

A very important group of people to consult too would be our patients. I want to find out what they think about their experiences at our clinics, and act upon them wherever needed.

This journey of life, of being a physiotherapist, of running our clinics is full of ups and downs. I keep my eyes on the big picture. The big picture is that each and every person who comes to our clinics feel heard, helped, understood and hopeful. That's really at the centre of all we do.

Sunday, October 16, 2022

My Patient Was Asked To Go For Functional Training

My patient said her friend told her she should attend a 'functional training' (FT) class in order to regain her strength and mobility after she broke her ankle. 

She was also told that that FT would improve her neuromuscular adaptations (increasing the efficiency the way her body moves and safety during activities related to daily living, work and sports). Other terms include high intensity functional training (HIFT) and functional fitness (FF).

I shared with her what I read regarding a review on whether FT programs are different from traditional strength, power, flexibility and endurance training programs that are already being used in the physical training of professional, recreational athletes, healthy adults and geriatric populations.

The authors focused on the FT definitions, exercises employed and the neuromuscular adaptations reported. Firstly, they found that there is no agreement on a universal definition for FT. 

FT programs hope to improve the same neuromuscular adaptations similar to traditional strength, power and endurance training programs. The exercises employed are in fact the same. 

The main confusion with these 'new' training programs is that (other than the new fancy names) they often always overlap with traditional strength, power, endurance and flexibility programs. There is also no precise definition of functional movements. Do our muscles perform any non functional functions?

Some studies have classified that FT involves resistance training while FF has been defined as a trend using strength training. So, both FT and FF can be easily described as strength training programs.

HIFT was defined as high intensity and high volume exercises with short rest intervals. This is similar to a strength, power, and endurance session elite athletes use during specific phases of training. In fact FF has also been known as HIFT. So FF is actually HIFT. Since exercise intensity is a training variable and not an exercise type, FT and HIFT is the same training program performed at different intensities.

The authors concluded that FT has no consistent and universal definition. FT programs and exercises are not different from those already used in sports training since the neuromuscular adaptations are the same. The authors concluded that FT is not different from traditional strength, power and aerobic endurance training.

In short, there is no "non-functional" or "traditional" training. There is no real need or rationale in classifying exercise training programs as FT.

The names of these new training progams may sound cool and fancy, but you now know that they are in fact similar to weight training. 

The authors also recommended that the terms FT, HIFT and FF no longer be used to describe any training program. These can be easily classified as strength, power, endurance and flexibility programs. I found that a little too harsh since they are just names to describe training programs. At least now you know.


Ide BN, Silvatti AP, Marocolo M et al (2022). IS There Any Non-functional Training? A Conceptual Review. Frontiers Sport Active Living.3: 803366. DOI: 10.3389/fspor.2021.803366.

Sunday, October 9, 2022

Thoracic Outlet Syndrome

picture from mountainhp
We had a Team Singapore cyclist who came to our clinic complaining of arm weakness, tingling sensations, pins and needles in his biceps and forearms after full on sprints. This did not happen during the sprints, but after. He also complained of neck pain and some sensations of electric currents in his neck region when he tried looking upwards.

picture from J Manip Phy Therapeutics
The doctor he saw at the Singapore Sports Institute diagnosed him with compartment syndrome in his arms. With compartment syndrome, as physical activity ceases, all symptoms should start to ease. My patient's discomfort and symptoms only started after he stopped sprinting.

Individuals with compartment syndrome will usually complain of pain, paraesthesia (or pins and needles), their limbs (usually legs) being very tight, tense and full of pressure during training or doing the offending activity. Temporary paralysis can occur sometimes. It usually happens to athletes at the start of the season, after their break when they train too hard, too soon. 

During exertion, the muscles expand and they fill up the space in the legs and "squeeze" the nerves and blood vessels there leading to sensations of tightness, pressure or pins & needles as the connective tissue that separates each section or compartment does not stretch hence leading to the term.

My patient probably has thoracic outlet syndrome (TOS) instead of compartment syndrome.TOS occurs when blood vessels or nerves in the space between the collar bone and first rib (this space is known as the thoracic outlet) are compressed causing neck, shoulder and arm pain and numbness in the arms and fingers.

There are a few types of TOS. My patient probably has the most common version known as neurological TOS, when the brachial plexus is compressed. The brachial plexus is a big network of nerves from the spinal cord and it controls muscle movements in the shoulder, arm and hand.

A common area where TOS occurs is in the interscalene triangle (formed by the brachial plexus, the subclavian artery exiting the neck area between the anterior and medial scalene muscles and the inner surface of the first rib). 

Brachial plexus
Entrapment in the interscalene triangle may be due to brachial plexus passing through the anterior scalene (especially when the anterior scalene is larger). In my patient's case, since he is a track cyclist (with bulging neck and arm muscles) who sprints in a velodrome with excessive traction forces while sprinting plus deadlifting and snatching the Olympic bar during weight training, all these factors could very well contribute to his TOS.

After a detailed questioning and physical assessment, we managed to treat his spine and and the nerves in that region. That cyclist was able to train without the accompanying pain and symptoms after.


Dahlstrom KA, and Oliver AB (2012). Descriptive Anatomy Of The Interscalene Triangle And The Costoclavicular Space And Their Relationship To Thoracic Outlet Syndrome: A Study of 60 Cadavers. J Manip Physiol Therapeutics. 35(5): 396-4001. DOI: 10.1016/jmpt.2012.04.017

Sunday, October 2, 2022

Coffee's Performance Enhancing Powers

I remember reading about how drinking coffee can help improve sporting performance in endurance races when I was 17 and competing in track and field races back then. I was not a regular coffee drinker then (nor now). I made myself a cuppa before a track race held at the NUS track (1500m) and ran a personal best!

Back then, I read that the caffeine in coffee was a stimulant and that it enhanced fat burning to give nuscles more energy. Another theory was that caffeine acts in the brain to make  physical exertion feel easier (by blocking receptors that detect adenosine, a molecule that detects fatigue). This also helps in all out bursts of strength, prolonged endurance and cognitive effects like enhanced attention and vigilance.

Fast forward to a recent study that involved cyclists who completed time ridden to exhaustion tests at a predetermined intensity. They could sustain that intensity for around 5 minutes on 9 separate occasions. They were wired up with electrodes and other equipment before and after the rides to assess brain function, circulatory system efficiency and muscle function.

The cyclists did similar rides each time. Either 5 miligrams per kilogram body weight of caffeine was ingested an hour before the ride, or a placebo was taken. In some rides, they stopped the ride prematurely at either 50 percent or 75 percent of the time achieved in the baseline test to assess mid ride neuromuscular function.

In the final ride, the riders were given caffeine but were stopped at the exact time they had given up in the previous placebo trial to get a similar comparison of the effects of riding at a given power for a given duration with or without caffeine.

Here's a summary from the fairly complex analysis by the authors. Caffeine works! The cyclists lasted 14 percent longer (5:55 min) with caffeine compared to the placebo (5:14 min). This is equivalent to a 1 percent gain if the riders did a race or time trial.

Caffeine did help the muscles delay loss of power. Those taking the placebo at the 75 percent mark of the test had lost 40 percent of muscle power compared to less than 35 percent for those who had taken caffeine. At exhaustion those taking the placebo could generate only 60 percent less force than when they were fresh. With caffeine, the loss was 45 percent at the exact same time, pace and power.

The brain (or central nervous system) sent weaker signals to get the muscles to work when the cyclists got more tired when they ingested the placebo. With caffeine, the signals never declined, even when the cyclists reached exhaustion. Their brains were still enthusiastically getting their muscles to contract.

Caffeine also kept oxygen flowing through their arteries, as measured by a pulse oximeter attached to the cyclists' right fingers. There was only a mild decrease at exhaustion compared to a steady decline seen in those who took the placebo. The authors suggested that having more oxygen available may be one of the reasons the muscles kept working better during caffeinated rides.

This study also shows that caffeine also reduced perceived effort - just like what I read when I was 17. The pace you're holding definitely seems easier.

For those of you that are keen to try caffeine, the authors suggest 3 to 6 milligrams of caffeine per kilogram of your body weight taken an hour before your event starts. Higher doses may speed up your heart rate, not what you need during your race. Regular coffee drinkers may get a slight gain if you stop drinking coffee for a week to get that boost.


Cristina-Souza G, Santos PS, Santos-Mariano AC et al (2022). Caffeine Increases Endurance Performance Via Changes In Neural And Muscular Determinants  Of Performance Fatigability. Med Sci Sports Ex. 54(9): 1591-1603. DOI: 10.1249/MSS.0000000000002944

Sunday, September 25, 2022

More Sugar More Pain?

Many patients tell me they have a high threshold for pain. Until I start to work on them. Then they change their mind (not everyone of course).

Being in the pain business (i.e. finding the cause of patients' pain and treating it), I've always been intrigued about how we tolerate pain. Some patients can definitely tolerate pain better than others.

The article referenced below (Ye et al, 2022) definitely caught my eye. The researchers investigated the effects of high blood sugar on pain sensitivity and pain inhibition (the act of stopping or slowing down pain) in healthy adults with normal and excess body fat.

The researchers found that ingesting just 75 grams of glucose (2 standard cans of soft drink) in the overweight group of subjects caused the subjects more pain when both their feet were submerged in cold water for 1 minute.

In addition, having acute hyperglycaemia (high blood sugar levels) also suppressed resting heart rate variablity (HRV) in the group with excess fat mass. *HRV is where the amount of time between your heart beats fluctates slightly.These fluctuations can indicated current or future health problems like heart conditions or anxiety and depression.

Regardless of blood sugar levels, the group with excess fat mass could not tolerate the pain from a pin prick after cold water immersion. This group also reported higher pain levels during a 5-minute period of blood flow occlusion.

In addition to the effects of high blood sugar on pain sensitivity and pain inhibition, effects on HRV and reactive hyperaemia (increase of blood flow) after arterial occlusion were also investigated. Both high blood sugar and excess body fat affected HRV and reactive hyperaemia only in people with extra fat mass.

Interpreted together, the researchers concluded that high blood sugar levels affected pain processing levels and autonomic function, especially in people with excess body fat mass. 

So, if you are overweight and consume more than 75 grams of sugar (2 standard cans of soft drinks) you will more likely feel more pain compared to someone who is not overweight.

The authors added that since both hyperglycaemia (high blood sugar levels) and being overweight are risk factors for diabetes, further research should be done on whether and how these sources of pain affects people with diabetes.


Ye D, Fairchild TJ, Vo L et al (2022). High Blood Glucose And Excess Body Fat Enhance Pain Sensitivity And Weaken Pain Inhibition In Healthy Adults: A Single-blind And Cross-over Randomised Controlled Trial. J of Pain. In Press, published 16 Sep 2022. DOI: 10.1016/j.pain.2022.09.006

*HRV responds uniquely for everyone. As a rule of thumb, values under 50 ms are unhealthy, 50-100 ms signal compromised health and readings above 100 ms are healthy.

Sunday, September 18, 2022

How Accurate Is Your Smart Watch?

I have noticed almost all my patients wear a smart watch now. Mostly an Apple watch. Actually, Aized recently has a patient who wears a Rolex on his left hand and an Apple watch on his right. He says he is a watch connoisseur (hence the Rolex), but the Apple watch is more practical since it monitors his health, allows him to read his whatsapp messages, email and also to make payments easily.

Are the readings for heart rate, calories used and energy expenditure accurate? Definitely more so if you have updated personalized metrics like your weight, height, age and gender to make the calorie estimates more accurate. That was what I thought until I looked it up.

I found a study that studied the heart rate and energy expenditure accuracy of the Apple watch, Fitbit Charge HR and Garmin Forerunner 225. All the watches overestimated energy expenditure. 

Another study looked at the Apple watch, Samsung Gear 2, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2 and the PulseOn. That study found that even though heart rate was adequately measured, energy expenditure was not.

A third study concluded that 2 fitness watches (Polar V800, Garmin Forerunner 920XT) and 3 activity trackers (Garmin vivosmart@HR, TomTom Touch and Withings pulse Ox) were not accurate enough to be used for sports or heathcare applications. Ouch! And I thought Polar and Garmin are the market leaders for sports watches. No prizes for guessing when measuring distances and altitude gain then.

The quality of heart rate data reading can affect accuracy. Compared to using a chest strap to measuring your heart rate with having an Apple watch on your wrist, the chest strap will be more accurate.

According to Apple, how snugly the watch fits against your skin, the surrounding temperature and tattoos can affect readings. The ink, pattern and saturation of some tattoos can block light from the sensor, affecting the reliability of readings. 

Yes, you read correctly, tattoos can affect your sporting performance as we have written before

Note that all the 3 studies had less than 100 participants each and technology for such watches and activity trackers are consistenly improving so the latest versions can be more accurate. For now, bear in mind that the readings are just an estimate.


Dooley EE, Golaszewski NM and Bartholomew JB (2017). Estimating Accuracy At Exercise Intensities: A Comparative Study Of Self-monitoring Heart Rate And Physical Activity Wearable Devices. MMIR Mhealth Uhealth. 5(3): e34. DOI: 10.2196/mhealth.7043

Passhler S, Bohrer J, Blochinger L et al (2019). Validity Of Wrist-worn Activity Trackers For Estimating VO2 Max and Energy Expenditure. Int J Environ Res Public Health 16(17), 3037. DOI: 10.3390/ijerph16173037

Shcherbina A, Mattsson CM, Waggott D et al (2017). Accuracy in Wrist-worn, Sensor-based Measurements Of Heart Rate And Energy Expenditure In A Diverse Cohort. J pers Med. 7(2): 3. DOI: 10.3390/jpm7020003

Wednesday, September 14, 2022

Team Building This Quarter

Our 3rd team building session for the year. One every quarter so far this year. We went to Ves Studio to learn pottery. We had great fun with Jeanette Wee teaching us. 
Jeanette is the real master here

Our hand skills in treating patients did not translate the same way however. 
Our craft

Stay tuned for the next team building session.
Group photo

Sunday, September 11, 2022

Deltoid Ligament Sprain? No! It's the Tibialis Posterior

R tibilais posterior
A patient who came in to see me yesterday was diagnosed with a deltoid ligament sprain in his left ankle. He had seen a doctor who referred him to a surgeon. An MRI was ordered, but all came back normal. The surgeon referred him for physiotherapy to treat his deltoid ligament.

L deltoid ligament from Dr R LaPrade JBJS
Here's what the patient told me. He was training for the Ironman 70.3 triathlon in Cebu, Philippines on August 7th, 2022. He had done a lot of  *'brick' training prior to the pain in his left ankle. Triathletes will know that *'brick' workouts are cycling followed by running straight after dismounting to simulate race conditions. One day before the race he felt a sharp left calf pain. As a result, he had to walk the whole run (21.1 km) during his race. Thereafter, after returning to Singapore, the inside part of his left ankle started hurting.

I assessed his ankle joint and his ankle proproception and both were good. No tenderness over the deltoid (inner) and outer ankle ligaments. There was however some tenderness behind his left medial malleolus (that bone sticking out at the inside ankle region) and definitely along his tibalis posterior muscle. Much more than his right ride. 

Single-leg heel raise (SLHR) test ability on the left elicited pain too. Bingo! For the physiotherapists and clinicians reading this, you may already know what is wrong with my patient. He had a problem with his left tibialis posterior. Yes, the same tibialis posterior muscle that can cause the dreaded shin splints and your arches to "collapse". Definitely not a deltoid ligament sprain in his case.

The SLHR test was described by a study (Ross et al, 2021) as one of 4 clinical tests to find out if a patient has tibialis posterior tendinopathy. The other 3 are; pain on tendon palpation, swelling around the tendon and pain and/or weakness with tibialis posterior muscle contraction.

My patient was happy to know that he can resume running after I treated him. 


Ross, MH, Smith MD, Mellor R  et al (2021). Clinical Tests Of Tibilailis Posterior Tendinopathy: Are They Reliable, And How Are They Reflected In Structural Changes On Imaging? J Orthop Sports Phys Ther. 51(5): 253-260. DOI: 10.2519/jospt.2019.9707

Picture by
*Brick training- short form for bike-run-in-combination. Perhaps also because it was name after a world champion duathlete and surgeon Dr Matt Brick who came up with the term whem he described his bike-run and run-bike training sessions while training for a duathlon race

Sunday, September 4, 2022

The Larger The Disc Injury The More Likely To Heal Without Surgery

Picture from article referenced below

I saw a few patients with slipped discs this past week. Most patients are still very fearful even if their 'slipped discs' happened years ago. They will complain that they have been having back problems ever since.

Having written previously about how 'slipped discscan heal I will share with my patients the facts about how the larger the disc injury, the more likely it can heal without surgery.

The picture above shows the diffferent types of herniated disc, bulging being the mildest and sequestration the most severe.

When there is a lumbar disc herniation, there is a tear or damage to the outer layers (annulus fibrosus) leading to leakage (or herniation) of the soft, gel-like inside material (nucleus pulposus). This leakage may touch or compress (irritate) the spinal nerves which causes an inflammatory response. This results in the patient complaining of pain, sensations of numbness, tingling sensations down their leg and sometimes neurological dysfunction.

Conservative management for 6 weeks (instead of surgical management) is usually the first choice for  newly diagnosed patients. In some patients, spontaneous reabsorption of the disc herniation is a widely recognized clinical observation. The spontaneous shrinkage or disapperance of a herniated lumbar intervertebral disc without surgery is called reabsorption or resorption.

The biological mechanisms involved in herniated disc resorption includes macrophage infiltration, matrix remodelling and neovascularization.

Since our immune system recognizes the gel leakage as 'foreigners' in our vertebral epidural space, this triggers a casade of inflammatory responses including phagocytosis of inflammatory cells, enzymatic degradation, increased inflammatory mediators. All of which means that healing is taking place. As the herniation decreases after resorption, the clinical symptoms also improve.

The type and composition of the herniated disc may predict the possibility of natural resorption. Extrusion and sequestration have a higher chance for resorption since the leakage is in the epidural space, creating favorable conditions for macrophage infiltration and neovascularization.

Picture from Radiopaedia
However if the area of the spine shows Modic changes, it is not conducive to macrophage infiltration and ingrowth of blood vessels, thus preventing resorption. Modic changes in the spine occur in response to degenerative changes of the discs, pathology or infections. 

An earlier meta-analysis of 38 clinical studies done in 2015 showed that resorption of lumbar disc herniation was as high as 62-66 percent (Chiu et al, 2015).

Further research is ongoing to understand what conditions can induce or promote the reabsorbtion of 'slipped discs'. This will help clinicians to rationally formulate treatment plans for patients.

Today is exactly one year on from my 2nd bike accident. Not the kind of anniversary I like to remember but it does mean that I've come quite a bit further than where I was. Of course I'm still not working the hours I did before the accident, but definitely much more than just after the accident. So I'm testimony that you can definitely recover, even after 2 compression fractures in my spine! 


Chiu CC, Chuang TV, Chang KH et al (2015). The Probability Of Spontaneous Regression Of Lumbar Herniated Disc: A Systematic Review. Clic Rehabil. 29(2): 184-195. DOI:10.118/269215514540919.

Yu P, Mao F, Chen J et al (2022). Characteristics And Mechanisms Of Resorption In Lumbar Disc Herniation. Arthritis Res Ther. 24, 205. DOI: 10.1186/s13075-022-02894-8

A meta-analysis of 38 clinical studies done in 2015 showed that resorption of lumbar disc herniation was as high as 62-66 percent.