Shouder Keeps Clicking But No Pain

I had a patient come in to our clinic this week complaining that his shoulder keeps clicking and popping with occasional discomfort (but not pain).

I shared with him an article published earlier this month where 100 patients with suspected rotator cuff tendinopathy and/ or tearing underwent MRI investigation. 

Indication for MRI was when the patients had weakness on testing of the rotator cuff muscle(s) or symptoms resistant to conservative treatment . This is inclusive of at least a 6-week course of physiotherapy. The presence of subjective mechanical symptoms, including clicking or popping was recorded prior to MRI.What the researchers were looking for was the presence of full or partial thickness rotator cuff tearing and biceps long head subluxation.

Results showed that 60 percent of the patients reported subjective mechanical symptoms in their affected shoulder. However only 42 percent of patients had full thickness rotator cuff tearing, 69 percent had partial tears while only 14 percent had biceps long head subluxation.

The authors concluded that subjective mechanical symptoms were not associated with any rotator cuff tearing, biceps long head subluxation. 

However, older age was associated with partial and full thickness rotator cuff tearing. Subjective shoulder mechanical symptoms has the ability of only 44 percent in predicting partial and full thickness rotator cuff tears. Patients may be reassured that clicking or popping sensations alone does not necessarily mean structural shoulder damage.

This article highlights the difficulty of diagnosing shoulder pain/ disorders based solely on symptoms like clicking and/ or popping. I have previously written and explained about this before. The clicking and popping sounds do not really matter, especially when there is no pain. Plus abnormal MRI findings happen in patients with no pain as well.

Reference

Zhang D, Dyer GSM and Carp BE (2024). The Significance Of Subjective Mechanical Symptoms In Rotator Cuff Pathology. J Shd Elbow Surg. 3: S1058-2746(24)000227-1

Help! My child Is Pigeon Toed

I saw a concerned parent this week who brought her child in to our clinic. She was told that her child had her feet pointing inwards while walking. This is also called in-toe or pigeon-toed walking. (If a child walks with their feet pointing onwards it is called out-toe walking or duck-footed).

These childrens' walking patterns are often termed "rotational deformities" which often cause parents to seek the opinion of podiatrists, physiotherapists or an orthopaedic surgeon for more specialized assessments and treatments.

Often when a baby is born, bowed or curved legs are normal due to the position they may be inside the mother's womb. This sort of bowed or curved legs can remain for a while and seem more obvious when the child starts to walk. It may appear that their feet face inwards (or outwards). Often the child may even trip or fall over their own feet while walking.

There may be different reasons why the child's leg or foot faces inwards or outwards while walking. When a child's leg or foot faces inwards or outwards during walking, it can be due to a number of changes in the leg or foot. If the foot is curved in ('banana' shaped feet ), or when there an inward twisting of the shin or thigh bone (tibial or femoral torsion), in-toe walking can occur.

Tibial torsion occurs when the shin (tibia) bone turns in or outwards. An inward-turned tibia is common in children under the age of 3. It almost always straightens after this age after this age (3) with NO treatment. Sometimes the shin bone even turns slighly outwards as the child grows order. This is perfectly normal. These changes occur in children up to the age of 8.

The are health professionals who will recommend that children with in-toe walking wear a type of orthotics called gait plates. While gait plates may provide some cosmetic effect when worn, there is insufficient evidence they will result in long term change. 

Parents please be very cautious about claims that such devices will fix your child's in-toe walking. Please consider if the expense, time, and your child's well being is worth it for something that will naturally get better on it's own. Do not let these health professionals prey on your fear.

Femoral torsion is when the femur (thigh bone) is turned in or outwards. Children may appear to walk with their feet tuning inwards or outwards. It then looks like their knees point inwards or outwards. 

The femur goes through many changes up to the age of 12 and this inward turn of the of the femur is more commonly seen in girls than boys. Please note that this rotational changes in the femur are a very normal part of growth.

W sitting

This inward turning at the top of the femur and hip sometimes appear in children who W-sit (pictured above) as well. There is however, no research proving that W-sitting is harmful.

There are no shoes, orthotics, garments, stretches etc that have evidence showing them being effective to change in-toe or out-toe walking associated with these rotational changes. Children walk in-toe or out-toe for many reasons. 

Unless your child is tripping often because of the leg position at the ages past 8 years of age, or if one leg turns significantly more in or outwards than the other. Unless one leg seems a lot longer or looks very different compared to the other, there is no reason to be worried. For the majority of children, in-toe or out-toe walking is just part of growing.

Actually, famous athletes like Michael Jordan, Bjorn Borg, Andre Agassi, Andy Murray, Vera Zvonareva, Zinadine Zidane and Ronaldinho are all pigeon toed. There is some anecdotal evidence and indirect research evidence to support that pigeon toed athletes have faster feet reaction times. And that will have to be in another post.

Reference

Mudge AJ, Bau KV, Purcell LN et al (2014). Normative Reference Values For Lower Limb Joint Range, Bone Torsion, And Alignment IN chldren Aged 4-16 Years. J Ped Orthop. 23(1) : 15-25. DOI: 10.1097/BPB.0b013e328364220a

Tight Or Just Tired?

Who says my hamstrings are tight?

I always hear my patients telling me that their muscles are feeling 'tight' or tense. Does this mean that their muscles are 'short' or have poor range of motion? Or is it that the area that they complain about is tight and does not feel relaxed or 'loose'. Perhaps there is a vague sense of discomfort, not pain, just an unpleasant feeling, but too mild to be painful.

I always explain that when I put both my hands on their e.g. trapezius muscles that they feel the same, one side is not 'tighter' than the other. 

If I get a dollar each time my patients tell me how tight they feel when they come and see me I will have many extra dollars for sure.

A patient ran a very hard 21 km road race recently and complained of 'tightness' in his hamstrings for the past 5 days came to see me in our clinic this week. He said his hamstrings felt very hard, achy and 'tight' of course. They even threaten to cramp when he tried running or doing some strengthening exercises. 

However, he can easily put his palms on the floor in a forward bend. (Note: there are other patients whose hamstrings do not feel 'tight' but they can barely get their hands past their knees while bending forward).

He tried stretching but other then feeling a little better for less than a minute the 'tightness' came back quickly. Upon assessment he definitely had some delayed onset of muscle soreness (DOMs). I told him his 'tightness' was actually fatigue from his training and racing.

I suggested resting and focusing on his recovery. Definitely decrease his intensity and mileage. My personal experience after a hard race would be doing any of the 2 aerobic exercses outlined below at reduced intensity and low volume.

These low intensity exercises will increase blood flow to the affected muscles and often reduce pain. Pedaling at low resistance on a stationary bike is ideal as you don't have to worry about traffic (if you ride on the roads). An easy swim or just walking in waist or chest high water works well too. Wearing compression garments will help reduce DOMs as well. These above mentioned strategies do have some support in the research.

After he recovers fully, I suggested testing for strength imbalances and deficits as weaker muscles do tend to fatigue more rapidly. Specific strength training will address that.

In most other cases of patients feeling 'tight', the reason is obvious. If the stay in the same position/ posture for too long, their muscles need a rest or change of position to reduce the lack of blood flow or metabolic stress that is causing the noxious stimuli. Think of the last time when you spent hours in a car, plane or behind your computer, after you move/ stretch, the symptoms of stiffness/ tightness will be alleviated.

Remember this, when you feel stiff and 'tight', it is just a feeling and not necessarily a physical shortening that needs you to structurally change it. Like other things that you feel, you may feel it more sometimes compared to others. Like other forms of sensitivity, those feelings will change if you improve your overall fitness, strength and health.

Reference

Stanton TR, Moseley GL, Wong AYL et al (2017). Feeling Stiffness In The Back: A Protective Perceptual Inference In Chronic Back Pain. Sci Rep. 791): 968. DOI: 10.1038/s41598-017-09429-1

Even Olympic Athletes Do Not Sleep Well

Thinking of winning even while sleeping

I managed to have an extra bike ride this week due to the Good Friday Public Holiday. If you include my regular Saturday bike ride, I rode 88 km a day on both days. Partly due to the heat, I felt extra tired, and did not sleep as well as I would have liked.

Whether you are an athlete or not you need to sleep. In theory, athletes need to sleep a lot, since sleep can boost performance, protect against injury and even help recovery. I have written before that a lack of sleep can lead to negative consequences. It can affect your mood, cognitive function and physical performance.

Ever wonder if champion athletes are also champion sleepers? Or they sleep just as badly as average athletes?

A recently published paper studied the sleep habits of more than 1600 Olympic and Paralympic USA athletes in the lead up to the 2021 Tokyo Olympics. The athletes filled up a Pittsburg Sleep Quality Index (PSQI) for that study.

The study compared the typical sleep pattern for male versus female athletes, summer versus winter Olympians and team versus individual sports.     

You may be surprised to know that almost 40 percent of athletes were rated as having poor sleep based on their PSQI scores. The scores accounted for how long they typically sleep, how often their sleep is disturbed, how long before they fall asleep and whether sleep medications were taken.

The results were similar to that of Dutch Olympic athletes (41 percent poor sleepers) and Australian Olympic athletes (52 percent poor sleepers).

A goal of the study was to provide what was normal values for athletes training hard compared to the general population on whom the PSQI was first tested. The PSQI has a maximum score of 21, the higher the number indicating a greater number or greater severity of sleep problems. A score of 5 and above classifies you as a poor sleeper. The average among the USA Olympians was 4.3. 

25 percent scored above 6 while 10 percent scored above 8 and 5 percent scored above 10. The top scorer was 16 while the lowest got zero (I am definitely envious)!

Reasons for the poor sleep? An early training session at 6 am will definitely affect sleep. Those athletes traveling across time zones to get to training camps/ races/ competitions will also be affected. If your legs or arms are aching from hard training ( I can testify to that), or if your heart/ mind is racing before a competition , you will not sleep well. That's my personal experience too.

The results do not specify what is happening exactly, but they do suggest that a serious athlete typically scores 5 or 6 on the PSQI, so they are classified as a 'poor sleeper'.

This study by Anderson et al (2024) has more subjects compared to previous similar studies which allows the data to be cetegorized into sub categories. Here is what else was reported. Female athletes had poorer sleep quality (4.7 versus 3.9) than men even though they went to bed earlier.

The female athletes were also less likely to report falling asleep straight away after going to bed. They were also more likely to report using sleep medication. A possibility is the variation in sex hormones across the menstrual cycle which may interfere with sleep, although no mechanism was found in this study. 

Team sports athletes got up earlier and had poorer sleep than individual sport athletes although this was not what previous studies found.. Perhaps a team mate who got up earlier caused the rest of the team to get up earlier as well?

May I boldly suggest that all the sub patterns were confounded by a huge variety of sports in this study. A runner is not equal to a tennis player or swimmer. Competition timings will play a part as well since most marathons are held in the early mornings compared to the later starts in some other sports. Especially those held in the late evenings. 

Defintely sleep is a great untapped frontier. Since 40 percent of Olympic athletes are poor sleepers, imagine one's advantage if you can improve or even master sleep.

Is good sleep "nice to have" rather than "need to have" for achieving sporting excellence? Or you may even argue that sleep may not be that important if all these Olympians are not sleeping well and are good enough still to compete at those lofty levels. 

Personally I do think sleep is important for sporting performance as well as keeping you sane during the day. 

On a side note, I will add that the cost to mental health is significant too, especially for the general population. Sleep problems may increase risk for developing certain mental illnesses like depression and anxiety disorders, as well as result from them. In this age of poor mental health among the young, are they getting enough sleep to begin with?

If you're an athlete, take your sleep habits seriously, but remember that if you still have problems, you are in Olympic level company.

Reference

Anderson T, Galan-Lopez N, Taylor L et al (2024).Sleep Quality In Team USA Olympic And Paralympic Athletes. Int J Sp Physiol Perform. 19(4): 383-392. DOI: 10.1123/ijspp.2023-0317

Just One Set Of Exercises Can Make You Stronger

Leg extension exercise

Doing just one set of exercises can make you stronger even if you are a "non-responder". But you will need to do more sets to get bigger muscles. At least that is what a recent study showed (Lixandrao et a, 2024).

This concept of non-responders were first described in studies done in the 1980s and 1990s. These studies explored the role of genetics in exercise response. 

When a bunch of people were given the same training program, their genes can explain about half the variance in how their fitness improves. Some people did not get fitter at all even after months of training. Note that later studies took the non-responders from a study and had them train harder or a higher volumes, they did get fitter. The studies above focused on aerobic exercise, but this study (Lixandrao et al, 2024) was on strength training. 

The authors had a total of 85 subjects (41 men, 44 women) above the age of 60 and not currently doing any strength training (Lixandrao et al, 2024). The study was designed to see if adding extra sets would turn the non-responder into responders. The subjects were assigned to different strengthening routines with each leg. That eliminates variations that can cloud results of strength training studies.

Note that older adults are usually less responsive to size and strength stimulus of strength training, making non-response more likely.

The exercse program consisted of 2 workouts a week for 10 weeks, Each set consisted between 10-15 reps of single leg knee extension with the weight selected to reach failure in each set. Each subject did 1 set per workout with one leg and 4 sets per workout with the other leg.

Muscle size of the subjects was measured by MRI. As expected, there were many non-responders who did the 1 set routine. 60 percent of the subjects did not gain more than 3.3 percent in the cross section of their quadriceps (this is the minimum threshold for a statisically significant improvement). 

The proportion of non-responders for those who did 4 sets decreased to 19 percent. Yes, you read this correctly, those who responded to only 1 set of training had bigger responses than those who did 4 sets!

Conclusion: Doing more sets lead to greater muscle gain, even among those who do not seem to repond initially.

Note that doing 4 sets of exercises did not produce bigger strength gains than 1 set, which was both surprising and unfair. Previous studies have also shown this in experienced lifters. Doing 5 sets was better than 3 sets, which in turn was better than 1 set for muscle size. However all 3 options were basically the same for muscle strength. 

Stength is a function of muscle size and the (complex) signaling process between brain and muscle. Both do not always go hand in hand.

Among those who responded to 1 set of exercise, only 51 percent got significantly bigger muscle size results from 4 sets. 15 percent actually did worse doing 4 sets. Note that the 1 set and 4 set parts of this study were taking place simultaneously in the same person but different legs. This may suggest that while 4 sets are better than 1 for some people, they really are worse for others.

Take away from this study (Lixandrao et al, 2024)? You can get away with a minimum of 1 set of strength training if your main goal is to get stronger. However, if your main goal is to gain or maintain muscle mass, you will benefit from more sets.

Note that the more interesting take away is this rule is not always true for everyone. Definitely a little annoying if you ask me. My suggestion? If what you have been doing is not working, even if it is suggested by the latest research, you need to try changing it.

Reference

Lixandrao ME, Bamman M, Vechin FC et al (2024). Higher Resistance Training Volume Offsets Muscle Hypertropjy Nonresponsiveness In Older Individuals. L Appl Physiol. 136(2): 421-429. DOI: 10.1152/japplphysiol.00670.2023

Knees Out Or Knees In When You Squat?

Out (left) versus in (right)

Here is a post that will perhaps change the way you squat. It depends on what area you want to work on. Previously, some physiotherapists and personal trainers hated me for saying that you can let your knees move forward when you squat. Most, if not all, personal trainers teach their clients that it is taboo to let your knees move forward while squatting, They get their patients or clients to stick their bums out instead.

Those same physiotherapists and trainers may be aghast if I suggest squatting with your knees pointing in (gasp!) or pointing out. 

The author recruited 14 males and 18 females for the squatting study (Chiu et al, 2024). Using 3D motion cameras and force platform meausures, normal squats required hip extensor, adductor and lateral rotator net joint movements (NJM). The gluteus maximus muscle exerts hip extensor and lateral rotator moments. The adductor magnus (pictured below) exerts hip extensor and adductor moments. Both muscles combine meet hip demands contributing to hip extensor NJM.

When squatting with hip in lateral rotation (feet pointing outwards), there was smaller hip extensor, lateral rotator and larger hip adductor NJM than normal squats. This loads the adductor magnus.

Medial rotation squats (feet pointing inwards) had smaller hip extensor and adductor NJM and larger hip lateral rotator NJM than normal squats. This loads the gluteus maximus.

Likewise if you stick your bum out when you squat, you are engaging more of your bum (Gluteus Maximus) muscles. If your let your knees move forward when you squat, you are definitely using your thigh (quadricep) muscles. If you want to increase hip adductor (adductor magnus) work, squat with your knees out. It just depends on what muscles you want to engage or work harder. Try it yourself.

There is definitely no real need to restrict forward knee movement when you squat. It's one of the biggest training myths ever. You can add squatting with your knees pointing inwards and outwards to the list of myths as well. 

This information should 'challenge' some old school "perfect squat" gurus.

Reference

Chiu LZF. "Knees Out" Or "Knees In"? Volitional Lateral Versus Medial Hip Rotation During Barbell Squats. J Str Cond Res. 38(3): 435-443. DOI: 10.1519/JSC.0000000000004655.

The Most Efficient Way to Run (According To Science)

I came across a recently published (6/3/24) systematic review on what is the most efficient way to run, according to science (Van Hooren et al, 2024). 51 studies were reviewed in this systematic review.

It's a long review paper, key findings in the pictures attached. Let me highlight some of the important points. The paper does lend some support for increasing your cadence or step rate to improve running economy as this increases leg stiffness and reduces vertical oscillation. When you watch some runners run, you can see that they tend to 'bounce' up and down while running, that is vertical oscillation. 

Initial Contact

At Initial Contact (or foot flat) phase, higher cadence (step rate) may be associated with a lower energy cost of running. Decreased trunk flexion and knee flexion during swing phase may also be associated with better running economy.

Mid stance 

During Mid Stance phase, decreased trunk flexion and reduced vertical oscillation may be associated with improved running economy. Increased vertical and leg stiffness may also be associated with lower energy cost.

Toe off

At the Toe Off phase, if trunk flexion and ankle plantarflexion are reduced, running economy may be improved.

Those metioned above are just he key findings which I have summarised. However, there are many more details and applications in the paper itself. You can read the free paper here.

I have previously written before on running cadence and running form if you wish to read further.

Reference

Van Hooren B, Jukic I, Cox M et al (2024). The Relationship Betwen Running Biomechanics And Runnng Economy : A Systematic Review And Meta-Analysis Of Observational Studies. Sports Med. DOI: 10.1007/s40279-024-01997-3

Summary

Can Your Sports Bra Restrict Your Breathing?

Excellent post by Aized on whether your sports bra can restrict your breathing when you exercise in our Physio Solutions blog. Have a read here.

What Time Do You Eat Dinner?

Picture from Yahoo

My patients are usually shocked when I tell them that I normally have dinner by 6 pm. My family usually has dinner at around 6 pm (plus minus 10 minutes). 

I do not know for sure what time most Singaporeans have dinner, but 3 in 5 Americans normally have dinner after 9 pm (Farsijani et al, 2023).

Our bodies are much better at digesting and processing nutrients during the day and powering down and resting at night. So eating close to bedtime can cause a whole range of issues. There are studies linking late night eating to heartburn while others demonstrate how it can affect your sleep quality. As you know, Singaporeans already do not have enough sleep. 

There are also recent studies that link late night eating with increases in body weight and the risk of diabetes. When you limit your calorie intake 3 to 4 hours before bedtime, it can help with blood sugar control and weight management (Vujovic et al, 2022). This is likely linked to the circadian clock which reduces the energy we use after a meal in the evening.

Again in America, early dinners seem to gaining popularity among Americans of all ages. 5 pm is the fastest growing time slot for dinner reservations while bookings for 8 and 9 pm are falling.

Surprisingly, many Gen z-ers are embracing this early bird lifestyle. Americans between the ages of 15 to 34 are getting more sleep each night (9 hrs 12 mins) over the last decade if you look at data from the U.S. Bureau of Labor Statistics. 

I am surprised to say that the youths (Americans at least) today are more well rested than I thought, possibly because these youths are ditching late night drinks in favor of . Less daily commuting in this era of remote work enables them to sleep in, while an increase in venture capital for sleep tech definitely helps too.

When you limit your calorie intake 3 to 4 hours before bedtime, it can help with blood sugar control and weight management (Vujovic et al, 2022). This is likely linked to the circadian clock which reduces the energy we use after a meal in the evening.

Eat early, sleep early that seems to be what the research is telling us to ensure good health . 

References

Farsijani S, Mao Z, Cauley JA et al (2023). Comprehensive Assessment Of Chrononutrition Behavirs Among Nationally Representative Adults: Insights From National Health And Nutrition Examination Survey (NHANES) Data. Clin Nutri. 42(10): 1910-19-21. DOI: 10.1016:/j.clnu.2023.08.007

Vujovic N, Piron MJ, Qian J et al, (2022). Late Isocaloric Eating Increases Hunger, Decreases Energy Expenditure, And Modifies Metabolic Pathways In Adults With Overweight And Obesity. J Clin and Transl Report. 34(10): 1486-1498. DOI: 10.1016/j.cmet.2022.09.007

Ulnar Nerve Entrapment

Left ulnar nerve

My patient who is a Team Singapore cyclist came in with a case of ulnar nerve entrapment on Friday. Ulnar nerve entrapment* is the second most common nerve condition happening in the upper limb after carpal tunnel syndrome.

The ulnar nerve arises from the brachial plexus at C8-T1 and travels down the inner part of the upper arm through the arcade of struthers (pictured below).

At the elbow, the ulnar nerve travels just behind the bony part on the inner part of the elbow. This is also know as the "funny bone" when you can get sensations of pins and needles after bumping the area. 

Picture by Conor Jones

As the ulnar nerve crosses the elbow, it passes through a bony tunnel and up to 2 other potential points for blockage making it vulnerable to pressure or stretching. Prolonged periods of sleeping with the elbow bent can also cause over stretching of the nerve. My patient hurt her ulnar nerve after riding for a few hours in a new position after changing her handlebars. Riding for a few hours on bumpy roads did not help. She had also fractured both her clavicles (R followed by L in the last few months). This is also known as the cubital tunnel syndrome.

The ulnar nerve supplies the sensation and muscles to the 5th and half the ring finger. Symptoms are related to degree of irritation of the nerve. They start off intermittent in nature and may only come on at night after the nerve has been stretched for a longer time. 

Pins and needles, aching or tingling in the little and/ or ring finger will be the common symptoms. This is what my patient felt. If the irritation persists, the symptoms may become constant and progress to numbness in the 5th and/ or ring finger and ultimately weakness in the hand.

As the ulnar nerve exits the bony tunnel, it goes into the flexor carpi ulnaris muscle. Follwing that at the wrist, it travels superficially to the flexor retinaculum and passes into Guyon's canal.  

R wrist

Guyon's canal is formed by 4 borders (pictured above). The roof is the palmar carpal ligament, the floor being the transverse carpal ligament, the ulnar (inner) border is the pisiform and the radial (outer) border is hook of hamate.  If the nerve is irritated at the wrist it is known as Guyon's canal syndrome.

Picture from Medical Art Library

The flexor carpi ulnaris and inner half of flexor digitorum profundus muscles are innervated by the ulnar nerve and the hypothenar muscles (pictured above).

Knowing the exact site of nerve irritation during an accurate clinical examination will help decide what needs to be done for treatment. Some doctors send their patients to do a nerve conduction test, but I personally find that an upper limb tension test (with radial nerve bias) done correctly does a much better job. Others may do ultrasound imaging to help diagnosis. Do not confuse it with thoracic outlet syndrome.

Just remember not to have a steroid/ cortisone injection.

*Ulnar nerve entrapments are commonly seen in cyclists, golfers, weightlifters and construction workers.

References

Kong G, Brutus JP, Vo TT et al (2023). The Prevalence Of Double- And Multiple Crush Syndromes In Patients Surgically Treated For Peripheral Nerve Compression In The Upper Limb. Hand Surg Rehabil. 42(6): 475-481. DOI: 10.1016/j.hansur.2023.09.002

Raut P, Jones N, Raad M et al (2022). Common Peripheral Nerve Entrapments In The Upper Limb. Br J Hosp Med. 83(10): 1-11. DOI: 10.12968/hmed.2022.011

Have a look at this ulnar nerve video.

Does Strength Training Help Runners Prevent Injuries?

Last week I wrote about how we have been told for years that the key to staying pain and injury free can be found somewhere close to your belly button. That got most people obsessed with strengthening their core or abdominal muscles. Which you know by now that it is not totally true.

Likewise many runners also believe that strength training like squats, deadlifts and other power lifting staples can make you faster, more powerful, more efficient and less injury prone.

Ever wonder what sort of strength training do top runners do? Blagrove et al (2020) did a survey of 667 distance runners (local to internationally competitive) about their strength and conditioning exercises. Most common was stretching (86.2 percent), core training (70.2 percent),  weight training (62.5 percent) and plyometric training (35.1 percent).

What was most interesting was the motivation these runners reported for the strength and conditioning routines. There were 2 main answers. Reducing injury risk (63.1 percent) and improving performance (53.8 percent). There was no relationship found between strength and conditioning training and injury history in runners. The key predictor of injury was training volume. The more you ran, the more likely you would get injured.

 In another systematic review published last month, Blagrove and colleagues (Wu et al, 2024) found that strength and conditioning does not appear to reduce the risk and rate of running related injuries (RRI). Please bear in mind that Richard Blagrove has authored a book Strength And Conditioning For Endurance Running and worked with many elite runners on their strength routines in case you think he is against strength training.

Their systematic review consist of 9 articles with 1,904 runners. Exercises done include lunges, squats, plyometric hops/ jumps, core routines, foot strengthening etc. Given the wide variety of of regimens, there was NO significant benefit for the exercise groups compared to the control group in injury risk (runners who got injured during the studies) or injury rate (how many injuries they suffered for a given amount of running).

For now that is the state and level of evidence we have with regards to strength and conditioning exercises preventing RRI. Strange that this approach (strength and conditioning) has robust evidence that it works in soocer, but not in running.

What was most interesting is that 3 of the studies that produced the lowest injury risk also happened to be the 3 studies where the exercise routines was supervised rather than assigned to be performed at home. Research shows that people tend to get bigger gains when they have a spotter or trainer looking on. Similarly, runners tend to run their intervals faster and more consistently when the coach is standing on the track with a stopwatch in hand. It could also be the only way to ensure people actually do the strength and conditioning exercises. 

I can remember many patients who come for a follow up visit claiming they have done their exercises diligently but cannot do it when asked to demonstrate it. A strengthening exercise can only work if you actually do it and have done it correctly.

Take home message? If the study (Wu et al, 2024) is true, strength training or other forms of exercise may not lower your risk of getting injured while running. Even though the logic is sound and evidence from other sports is positive. However, there is very good evidence that strength training improves running economy and boosts long term health. It would be nice to get injury prevention as an added bonus but it still sounds like a good deal to me. So I will still strength train.

Researchers need to have more robust studies that include supervised interventions to investigate further.

References

Blagrove RC, Brown N, Howatson G et al (2020). Strength And Conditioning Habits Of Competitive Distance Runners. J Stren Cond Res. 349(5): 1392-1399. DOI: 10.1519/JSC.0000000000002261.

Wu H, Brooke-Wavell K, Fong DTP et al (2024). Do Exercise-Based Prevention Programs Reduce Injury In Endurance Runners? A Systematic Review And Meta-Analysis. Sports Med. DOI: 10.1007/s40279-024-01993-7.

Weak Core, Tight Hamstrings And Weak Glutes?

Hope you have been enjoying your Chinese New Year break!

A patient came in this past week with low back pain and was told by another physiotherapist that she had a weak core, tight hamstrings and weak glutes and that was why her back hurts.

Now, I do not agree with that. Actually studies show that back extensor strength is more important than  flexor (abdominal) strength when it comes to low back pain (Lee et al, 1999).

Like I wrote previously, the idea for the need of a strong core was first introduced by Paul Hodges (Hodges and Richardson, 1998) when he published his article on the Transverse Abdominis (TA) muscle. His research compared the timing of TA and Multifidus in people with low back pain (LBP) for 18 months or more against healthy subjects with no LBP.

Hodges suggested that the TA was likely to be the main cause of LBP as it is the most important and deepest muscle in the abdomen. It looks and works like a corset to stabilise the back.

This article made the allied healthcare/ fitness industry conclude that the TA was a trunk stabilising muscle that was very important to strengthen for those with LBP. Patients who had LBP had weaknesses in their TA which led to instability in the spine.

Similarly with 'tight' hamstrings (Halbertsma et al 2001) and weak glutes. This female patient of mine can deadlift 90 kg. Her glutes are not weak nor are her hamstrings tight. 

You can put all those myths to rest. Your low back pain is not caused by a weak core, tight hamstrings nor weak glutes. Stengthening your back extensors will be a much better option than the previously mentioned.

References

Halbertsma JP, Goeken LN, Hof AL et al (2001). Extensibility And Stiffness Of The Hamstrings in Patients With Nonspecific Low Back Pain. Arch Phys Med Reh. 82(2): 232-238. DOI: 10.1053/apmr.2001.19876

Hodges PA and Richardson CA (1998). Delayed Postural Contraction Of Transversus Abdominis In Low Back Pain Associated With Movement Of The Lower Limb. J Sp Disorders. 11(1): 46-56.

Lee JH, Hoshino Y, Nakamura K et al (1999). Trunk Muscle Weakness As A Risk Factor For Low Back Pain. A 5-year Prospective Study. Spine (Phila Pa 1976). 24(1): 54-57. DOI 10.1097/00007632-199901010-00013

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Tread Lightly To Avoid Knee Pain

Picture from Functional Path Training

My first running coach once gave my cross country team mates and I this advice. Land 'softly' while running. "Imagine you're running on egg shells and you do not want to break them further". A few of the boys commented that it was too 'difficult'. 

The coach then suggested to us that we run like ninjas, taking smaller and quicker steps. In fact, he made us practice that. We had to run as close to other pedestrians from behind (sharing the sidewalk) without startling them while we ran past. Turns out my running coach was correct as it helped my team mates and I avoid knee pain.

Here's the evidence. A group of researchers wanted to investigate whether 2 different 2-week partially supervised gait retraining programs were effective for runners with knee pain. They randomly allocated 30 runners to 3 groups. One group focusing on reducing impact, a group on cadence and a control group. 

Visual feedback to reduce impact in the study

The impact group (land softly) received instructions to reduce tibial acceleration (impact) by 50 percent while the cadence group was asked to increase running cadence by 7.5-10 percent. The control group did not receive any intervention.

Running pain (before and during the run), knee function, lower limb kinematics (contralateral pelvic drop, hip adduction, tibial, and foot inclination) were assessed before, immediately and 6 months after the intervention.

Picture A- Injured runner with CPD and right hip adduction

Compared to the control group, both the 2-week partially supervised gait retraining programs focusing on reducing impact and increasing cadence were more effective at improving knee pain up till 6 months after the intervention. In addition, the impact reducing program was more effective at improving knee function immdiately post run. 

So if your knee pain is stopping your from running, try landing softly and/ or taking smaller, quicker steps. Hey, my running coach was right, way ahead of his time. 

Reference

De Souza Junior JR, Rabelo PHR, Lemos TV et al (2024). Effects Of Two Gait Retraining Programs On Pain, Function, And Lower Limb Kinematics In Runners With Patellofemoral Pain: A Randomozed Controlled Trial. 10(1): e0295645. DOI: 10.1371/journal pone.0295645

As Peter Larson's book from 2012 says, tread lightly .....

Diastasis Recti

Picture from Lamaze.org

I saw a patient this week who had given birth to her second child about 3 months ago. Her friend told her that her belly was sticking out and the bulge may remain for months or years post partpartum. 

She has diastasis recti of about 2 fingers width. She was afraid that she would have low back pain and incontinence if the diastasis recti was not corrected.

Diastasis recti (DR) is the separation of the rectus abdominis (or 6-pack ab) muscles during and after pregnancy. The rectus abdominis runs in a straight line along the front of your stomach. A band of connective tissue called the linea alba divides the rectus abdominis into left and right sides. In simple terms it is the separation of the six-pack muscles into 2 halves.

It happens when the rectus abdominis muscles separate during pregnancy after being stretched. The linea alba becomes thinner and gets wider as it gets pushed by the uterus when it expands. The criteria for the diagnosis of DR is a gap or separation of more than 1.5 cm at one or more points of the linea alba.

Here is how I measure/check for the tummy gap. I get my patient to lie supine with knees bent and hip width apart. I place 2 fingers above her belly button. Then I get her to slowly lift her head, neck and shoulders off the bed like a low level sit-up. I then move my fingers below and above the belly button length wise and feel for any gaps and whether I can fit more than 2 fingers width wise. It's easy to feel for the gap this way.

After the baby is delivered, the linea alba can retract as the connective tissue is highly elastic. It can retract (like a rubber band). This usually happens for some new mums, the linea alba repairs itself within 10-12 weeks. However, when the linea alba loses its elasticity from being overstretched (larger babies) and/ or from a second and third pregnancy, the gap widens in the rectus abdominis.

Many patients have been told (by healthcare practitioners) that if DR continues after 10-12 weeks, their stomach/ core muscles cannot function efficiently and cannot properly support the lumbar spine (low back) or stomach contents. 

These same healthcare practitioners that treat diastasis recti will NOT be happy reading what I write next. Yes, women with DR may have weaker abdominal muscles (and perhaps more abdominal pain) BUT no higher prevalence of pelvic floor disorders (or incontinence), low back pain and pelvic girdle (hip) pain than women without DR (Gluppe et al, 2021). 

In fact, subgroup analyses comparing women with severe and moderate DR to women without DR showed no difference in abdominal strength, pelvic floor disorders (incontinence), low back pain, pelvic girdle and abdominal pain (Gluppe et al, 2021). This is actually the first study to investigate possible consequences of DR in a subgroup of women with moderate to severe diastasis.

I did not come up with that. There are many published research contrasting all that BS (excuse my language) about getting low back pain if you don't 'fix' your diastasis recti (Benjamin et al, 2019).

These studies contradict the common belief there there is an association between diastasis recti and pelvic floor disorders.  It does not mean that you definitely need treatment if you have a gap in your tummy after giving birth. Do not allow others to frighten you by saying that you will have back aches/ pain, weak core, hip, pelvic girdle pain and even incontinence if you don't 'fix' it.

So did I manage to reduce the tummy gap in my patient? I did and that may have to be a different post.

References

Benjamin DR, Frawlwy HC, Shields N et al (2019). Relationship Between Diastasis Of The Rectus Abdominis Muscle And Musculoskeletal Dysfunctions, Pain And Quality Of Life: A Systematic Review. 105(1): 24-34. DOI: 10.1016/j.physio.2018.07.002

Giuppe S, Engh ME and Bo K (2021). Women With Diastasis Recti Abdominis Might Have Weaker Abdominal Muscles And More Abdominal Pain, But No Higher Prevalence Of Pelvic Floor Disorders, Low Back And Pelvic Girdle Pain Than Women Without Diastasis Recti Abdominis. Physiotherapy. 111:57-65. DOI: 10.1016/j.physio.2021.01.008

*Thanks to Kaylee and Vean for getting me the articles

Intense Static Stretching Versus Strength Training For Muscle Growth

Static stretching device

Who says that strength training is needed to make muscles bigger and stronger? A study published 2 days ago showed that intense static stretching of the pectoralis major (chest) muscles 4 times a week produced similar hypertrophy gains to strength training done 3 times a week. 

What? Just as effective as strength training? I was surprised to say the least. Well you know I am not a big fan of static stretching at all. Skeptical? I was too!

81 participants were allocated to 3 groups in this study. A static stretching group, strength training and control group. Pec stretching was done for 8 weeks, 4 days per week for 15 minutes per day. Those in the strength training group trained 3 times a week doing 5 x12 repetitions. All the subjects were instructed to maintain their regular exercise routine during the study. They exercised at least twice a week in a wide range of sports like fitness training, team sports or strength-endurance training. 

Results showed significant strength increase in the static stretching and strength training group compared to the control group. There were no significant differences between the static stretching and strength training group.

There was moderate muscle thickness increases in the static stretching and strength training group compared to the control group. Muscle thickness was measured using ultrasound imaging. There was actually no difference between the static stretching  and strength training group.

Range of motion test

In terms of range of motion (ROM), static stretching group had significant moderate ROM increases compared to the strength training group. No difference in ROM between the strength training and control group.

It has been suggested that the shared underlying physiological mechanism between stretching and strength training is the high stretching tension both produces to induce stretch mediated hypertrophy (Warneke et al, 2023). This tension translates into chemical signals that stimulate anabolic processes to generate new muscle tissue.

Wow. Increased size, strength and range in 8 weeks compared to strength training. However, note that static stretching via a stretching device like in this study needed a second person to assist and adjust the stretching device. Moreover, regular strength training can prevent osteoporosis and sarcopenia.

References

Warneke K, Wirth K, Keiner M et al (2023). Comparison Of The Effects Of Long-lasting Static Stretching And Hypertrophy Training On Maximal Strength, Muscle Thickness And Flexibility In The Plantar Flexors. Eur J Appl Physiol. 123(8): 1773-1787. DOI: 10-.1007/s00421-023-05184-6

Wohlann T, Warneke K, Kalder V et al (2024).Influence Of 8-weeks Of Supervised Static Stretching Or Resistance Training Of Pectoral Major Muscles On Maximal Strength, Muscle Thickness And Range Of Motion. Eur J Appl Physiol. DOI: 10.1007/s00421-023-05413-y