Bow Legged Or Knocked Knees? Or Normal?

Different knee shapes

Visual inspection of lower limb alignment is common standard practice for us in our clinics (and elsewhere I am sure) when a patient comes in with ankle, knee, hip and low back pain.

You would think that as a trained health professional, we would be able to see if a person has normal, bow legs (varus) or knocked knees (valgus) quite easily. If it was an extreme valgus or varus it would be fairly easy to differentiate. What if you saw the following pictures below?

Varus or valgus?

How about this? Confused?

Hence I was rather surprised when a published study (Nguyen et al, 2022) found that visual inspection of lower limb alignment is not valid nor reliable when compared to the gold standard of whole leg radiography (WLR).

The study involved 50 patients who underwent a WLR and a standardized digital photograph of the lower limbs (pictured below). The patient's feet were placed 10 cm apart and in 10 degrees of external rotation with knees in full extension and both arms alongside the body. Pictures were taken from knee height, 2 meters away from the patient. 

WLR and digital photograph

There were 4 assessors who rated the digital photograph twice. Two are orthopaedic surgeons with 10 and 5 years experience respectively. The remaining two were an orthopaedic resident and a researcher. They were unaware of the patients' hip knee angle (HKA).

Knees were rated with severe valgus (>5 degrees), moderate valgus (2-5 degrees), neutral, moderate varus (2-5 degrees) and severe varus (>5 degrees).

Ready for the results? The percentage of incorrect visual leg assessments ranged between 46-75 percent. Now that's high! The errors were lowest in patients with moderate valgus alignment (knock knees) and highest when the patient presented with a severe varus deformity (bow legs). See the picture below of a patient I saw recently. How can the error be highest when it is bow legged? Isn't that fairly obvious?

Surely this varus is obvious

There were patients with a neutral leg alignment but were assessed to be pathological in 50.7 percent of cases. I am concerned about this since the wrong diagnosis of normal presentation as pathological/ dysfunctional may potentially cause the patient to opt for surgical intervention. This will lead to increased health care cost for patients and insurers.

Interestingly, there were no significant differences between the accuracy of more experienced verus less experienced assessors.You would think that the ability to assess alignment would improve with practice through one's working life.

The results also show that there were gender influences. Women do present an increased risk for incorrect readings due to the difference in the angle of the thigh bone between men and women.

The authors concluded that visual assessment of lower limb alignment does not provide clinically relevant information. Physical examinations and X-ray assessments are advised.

Limitations for this study? My biggest gripe was that visual assessments were done on 2-dimensional (2D) digital photographs instead of in person assessment. It is definitely easier (and more accurate) to visually assess a patient than to look at a digital photograph. Only 1 assessor measured the HKA on the WLRs, so there is no comparison for inter-assessor reliability.

Hopefully our surgeons here in Singapore are better are visually assessing patients. They should also do whole leg x-rays and in clinic assessments. Make sure yours does.

We see many of these cases. Come see us in our clinics if you have any pain or discomfort. While we cannot alter the shape of your knees, we can definitely reduce or take away the symptoms.

Reference

Nguyen HC, Egmond N, De Visser HM et al (2022). Visual Inspection For Lower Limb Malalignment Diagnosis Is Unreliable. Cartilage. 13(4): 59-65. DOI: 10.1177/19476035221113952

Should You Strength Train On Unstable Surfaces?

On the BOSU ball

A patient come to our clinic this week injured after lifting weights on an unstable surface. The studio he went to had them do chest presses and flys with a glute bridge on a BOSU ball (knees bent, buttocks up and feet resting on BOSU ball). 

Indo board

I often use the BOSU ball, wobble board and/or  Indoboard (much later on - see end of article) when my patients require proprioceptive training to prep them before they return to sport. Also for those if they have lots of metalwork (pictured below) in the ankle after a fracture. I find that challenging my patients on unstable surfaces may enable them to rehab faster compared to stable surfaces when it is safe to do so.

Check out all the metal work in the leg

Other than working on their balance and proprioception (joint position sense), I get them to step on and off, lunge sideways, forward, backwards and sideways so they will be ready when the terrain that they are on are cambered or cobblestones (especially overseas).

However, I never use them while doing strength training. Turns out there is some research supporting that. I came across the following article to investigate if there are benefits or cross over effects of strength training on an unstable surface.

The following study evaluated subjects undergoing stable and unstable resistance training for muscle power. The subjects were randomly assigned into 2 groups. Each group performed resistance exercises under stable or unstable conditions 3 times a week for 8 weeks. 

Before and after 4 and 8 weeks of the training program, the subjects underwent squats and chest presses on either a stable surface or BOSU/ Swiss ball with increasing weights of up to 85 percent 1RM (rep max). 

There were significant improvements of mean power during chest presses on a Swiss ball at weights up to 60.7 percent 1RM after 4 and 8 weeks of raining on an unstable surface. Mean power also increased significantly during squats on a BOSU ball at weights up to 48.1 percent for 1RM after 4 weeks but not after 8 weeks of training on an unstable surface.

There were no significant changes in mean power during bench presses and squats on a stable surface after the same training. We do know from previous studies (Zemkova et al, 2014) that lower pre training values of power during resistance exercises on unstable surfaces are expected when compared to stable surfaces, especially at higher weights.

The researchers concluded that there is no cross over effect while weight training on unstable surfaces. Training has to be specific, if you want to get really strong and increase your 1RM max, you do not train on unstable surfaces since you cannot lift as heavy compared to on a stable surface.

Now you know, so you do not get hurt while trying something different that your gym suggests you do.

References

Zemkova E, Jelen M, Cepkova A et al (2021).There Is No Cross Effect Of Unstable Resistance Training On Power Produced During Stable Conditions. Appl Sci. 11(8): 3401. DOI: 10.3390/app11083401

Zemkova E, Jelen M, Kovacikva Z et al (2014). Weight Lifted And Countermovement Potentiation Of Power In The Concentric Phase Of Unstable And Traditional Resistance Exercises. J Appl Biomech 30: 213-220. DOI:10.1123/jab.2012-0229.

How's that for balance?

What Happens If You Have A Bone Bruise?

R knee bone bruise from Theinjurysource

A patient I saw recently had quite a big bone bruise on his tibia (shin bone) and femur (thigh) after tearing his ACL. They are also known as bone contusions. It is similar to a bruise you may get on your skin after a fall or when you bump into the corner of a table or chair. It can also be more serious than a bruise under your skin.

A bone bruise (or contusion) refers to blood that is trapped under the surface of your bone after an injury. Since bone is also living tissue, it can also get injured or bruised like your skin and muscles. It usually takes much more force to bruise your bone to injure it without breaking it. A bone bruise usually feels like a deep, dull and throbbing ache that's coming from deep inside the body.

We normally see bone bruises in our clinic after an acute ankle sprain or ACL tear. What's the implication of having a bone bruise? An article (Kia et al, 2020) looked at the incidence of changes on the articular cartilage surfaces on MRI five years after the ACL tear. Note that this is done without correlation with clinical and functional outcomes.

The authors found that the lateral (outside) tibia (shin bone) and femur (thigh) are more frequently involved. The area that was initially bruised sigificantly correlated with increasing chondral (articular cartilage) wear over time. The larger the bone bruise, the higher the chances of having a significant change in the articular cartilage 5 years post surgery.

Absence of a bone bruise on initial MRI was the greatest predictor of no cartilage wear at 5 years in all compartments of the knee. If there was a lateral meniscus injury, there was an increased risk of wear in the lateral tibial plateau (shin bone).

We do not know if this wear leads to pain or even the need for a joint replacement further down the road since the scans DO NOT always correspond with the patients' symptoms.

I always communicate this with the rest of my team seeing patients with bone bruises since this will affect and influence progression to activities of daily living and especially back to sport.

No one knows how long the bone bruises take to heal. In my case before I had the first of my 3 knee surgeries, the bone bruising was still seen on my repeat MRI 9 months later despite me not running or jumping while waiting for it to heal.

For the athletes, impact related activities should only be considered 16-20 weeks after surgery, especially running and plyometrics so as to decrease pain and swelling.

The patient needs to be progressed slowly to have long term success. Slower will always be better in these cases.

Reference

Kia C, Cavanaugh Z, Gillis E et al (2020). Size Of Initial Bone Bruise Predicts Future lateral Chondral Degeneration In ACL Injuries: A Radiographic Analysis. Orth J Sp Med. 2020: 8(5). DOI: 10.1177/2325967120916834.

Physical Activity And Pain Tolerance

Picture from Science News

Almost all of my patients tell me they have a high tolerance for pain. That seems to be the most common reason why they sometimes do not come in early for treatment, thinking that they can tolerate the pain until it somehow goes away on its own. Some patients do have a higher tolerance for pain compared to others. Consuming too much sugar can be a contributing factor, I've written on that before. The following article may give further clues on why.

Since there are limited information on the association between lifestyle factors and pain severity in older adults, a group of researchers decided to investigate if unhealthy lifestyle variables were linked to feeling more pain.

Subjects who were above 50 years living in 27 European countries and Israel were sampled and their data retrieved. Association between lifestyle actors (smoking, sleep, diet and physical inactivity) and how they tolerated pain (mild, moderate or severe) were assessed. Age, sex, geographic region, education, history of chronic disease were all mutually adjusted for each lifestyle.

A total of 27,528 cases were included. The average age was 73 years and 63.3 percent of the cohort were female. A significant association was observed between those who hardly ever or never engaged in activities that required a moderate level of energy and severe pain (pictured above).

In addition, sleep problems, smoking and an inadequate diet were also significantly associated with severe pain, although with lower odds. 

The authors concluded that older adults that were physically inactive were more likely to experience severe pain. Sleeping poorly, smoking and an inadequate diet were less associated with experiencing severe pain. 

Since the above mentioned lifestyle factors are modifiable, they suggested that they may be useful as preventative measures to reduce pain and ensure healthy living.

Previously, I wrote about how strength training helps prevent frailty, especially when you grow older. Well, that's another very good reason to be active.

Reference

Numez-Cortez R, Cruz-Montecinos C, Lopez-Bueno R et al (2025). Physical Activity Is The Most Important Unhealthy Lifestyle Factor For Pain Severity In Older Adults With Pain. A SHARE-based Analysis Of 27,528 Cases From 28 Countries. Musc Sci Pract. DOI: 10.1016/j.mskp.2025.103270

Get Smarter By Taking Creatine?

Picture from Runnersworld

I first wrote about creatine supplementation and its role in improving physical performance back in 2022. So why am I writing about creatine again? Other than its role in improving physical performance, creatine has been shown in several clinical trials to improve mood and help symptoms of depression. It can help with short tem memory and reasoning (Avgerinos et al, 2018).

More importantly, there also seems to be data that research scientists gathered (but not studied yet) that there was a link between creatine and brain health.

Creatine may ease symptoms with certain neurodegenerative diseases (like Alzeimer's, Parkinson's etc), stroke and also adolescent depression. It may also help prevent as well as treat traumatic brain injuries and concussion.

In a meta-analysis of 16 creatine studies published last year, researchers found that creatine supplementation may improve memory, attention and information processing in adults (Xu et al, 2024).

Those of you who take mega doses of melatonin to sleep may want to try creatine instead. A dose of 15-20 grams of creatine monohydrate actually lessen the effects of a bad night's sleep by stimulating the brain's mitochondria (Gordji-Nejad et al, 2024).

Researchers suggest that our brain consume energy just like our muscles, accounting for as much as 20 percent of our body's energy consumption. Adenosine triphosphate (ATP) which is made from creatine may also be stored in our brain which is used for tasks and general health.

Creatine is also safe to take long term (21 months) with no health changes to the liver and kidneys (Kreider et al, 2003). A 2007 statement by the International Society of Sports Nutrition said that creatine was "safe, effective and ethical."

But, before you run out and buy some creatine or order online, I would urge some caution since another 2024 review concluded that creatine supplementation had no significant effect on the brain health of healthy and young participants. It had mixed results for those with creatine deficiences - vegans/ vegetarians, the elderly, the sleep deprived and mentally fatigued (McMorris et al, 2024).

If you decide to start taking creatine, note that 5 grams per day is for muscle growth and performance benefits only. Research has not found what dosage is required for cognitive gains. Some research suggest at least 10 grams and as much as 15 grams each day. The bulk of research indicates that taking 0.1 grams per kilogram of body weight per day is safe.

References

Gordji-Nejad A, Matusch A, Kleedorfer S et aL (2024). Single Dose Of Creatine Improves Cognitive Performance And Induces Changes In Cerebral High Energy Phospates During Sleep Deprivation. Sci Rep. 14(1): 4937. DOI: 10.1038/s41598-024-54249-9

Kreider RB, Melton C, Rasmussen CJ et al (2003). Long-Term Creatine Supplementation Does Not Significantly Affect Clinical Markers Of Health In Athletes. Mol Cell Biochem. 24(1-2): 95-104. PMID : 12701816

McMorris T, Hale BJ, Pine BS et al (2024). Creatine Supplementation Research Fails To Support The Theoretical Basis For An Effect On Cognition: Evidence From A Systematic Review. Beh Brain Res. 466: 114982. DOI: 10.1016/j.bbr.2024.114892

Xu C, Bi SY, Zhang WS et al (2024). The Effects Of Creatine Supplementation On Cognitive Function In Adults: A Systematic Review And Meta-Analysis. Front in Nutr. DOI: 103389/fnut.2024.1424972

Take 12 Weeks Off And Come Back Stronger?

Consider the following scenario. You have trained well and have just taken part in the Swimrun World Championships. You then take 12 weeks off from training. You resume training again for 12 weeks and tests show your VO2 max levels exceeded those just before you took 12 weeks off. 

Too good to be true? Can a long break be that good for you? 

A French exercise physiologist and triathlete Romuald Lepers agreed to take 12 weeks off deliberately (for the sake of science) and allowed himself to be tested. With his colleagues' help, he underwent a whole bunch of tests straight after he competed in the World Swimrun Championships in 2022. After that he rested for 12 weeks and the tests were repeated. He then resumed training for 12 weeks and repeated the same tests. 

The results were published in 2 different journals last year showing what happened when you lose and then regain fitness, raising a possiblity that perhaps a long training break is actually good for you.

The first published article documents Leper's changing fitness. After 12 weeks of rest, his VO2 max measured in a treadmill running test dropped by 10.9 percent. In a similar test on an exercise bike, it dropped by 9.1 percent. That's a big drop equivalent to about 15 years of normal aging. For reference, Edward Coyle's famous paper from 1984 saw a 16 percent drop in VO2 max after 12 weeks of laying off training.

Here's the surprising good news. He gained 5.5 pounds of fat and lost 4.6 pounds of muscle during the 12 weeks rest. After retraining, he lost 9 pounds of fat and regained 2.4 pounds of muscle. His body fat levels  went from 10.1 percent to 13.3 percent then to 8.4 percent. A net loss of 5.7 percent at the end of the experiment. 

Cycling VO2 max levels

After 12 weeks of training again, his VO2 max did not just recover, it was better than before he stopped training (5 percent higher). The running test was 4 percent higher than before. In the cycling test it was 6 percent higher (pictured above). 

The fat loss will explain some of the improvement in his VO2 max as it is calculated relative to body weight, so losing weight can create the 'illusion' that you get fitter without changing your oxygen processing abilities. However, his overall oxygen processing capacity did improve, independent of his weight.

Another possibility documented in the second published journal is that something changed in his muscles making them more responsive to training. Lepers had muscle biopsies (ouch - they are very painful!) at each stage to measure the chemical changes occuring. Fast twitch muscle activity was ramped up during detraining while aerobic capacity and mitochondria function decreased. Retraining mostly reversed those changes and in his case resulted in better than baseline muscle properties.

Now, Lepers is an accomplished triathlete. In his younger days he placed in the top 150 at The Hawaii Ironman World Championships. At the time of the study, he was 53, training 10-12 hours a week and consistently placing near the front in his age category in Ironman 70.3 races. Lepers has trained consistently for more than 3 decades, and never missed more than 2 weeks of training at a time previously. 

Sounds good so far? Leper's results also seem to line up, declining with detraining and impoving to be even better with retraining.  If you're in your 20's, you can take 12 weeks off, train hard again and definitely regain your fitness and more. This case study suggest the same can be true in your 50's.

Note that this is just a case study, where n=1 where we may not get the same results as Lepers. This is different as missing 12 weeks through injury since you may not be able to start training full on especially if surgery was needed.

So here are the not so good bits if you read both articles in detail. Leper's cycling efficiency went down and his running economy worsened. He did not recover the muscle mass he lost and that is worrying (note to self : need to maintain strength training). Fortunately for him, his race results in the following season with similar with the previous season. Actually I thought that was remarkable given the fact that he took 12 weeks off.

I really liked Leper's experiment since I am in the same age group as him. Many of my older patients and friends take shorter and less frequent breaks from training because they are afraid they will lose their fitness from too long a break. I am definitely in the same boat. Now we can all be less paranoid about taking long breaks from training. Even if I do not get better than before, just the fact that one can get back to your previous level is reassuring enough.

Reference

Lepers R, Mater A, Assadi H et al (2024). Effect Of 12 Weeks Of Detraining And Retraining On The Cardiorespiratory Fitness In a Competitive Master Athlete: A Case Study. Front Physiol. DOI: 10.3389/fphys.2024.1508642.

Zanou N, Gremeaux V, Place N and Lepers R (02024). Cardiovascular And Muscular Plasticity In An Endurance-Master Athlete Following 12 Weeks Of Detraining And Retraining: A Case vStudy. JCSM Comm. 7:82-90. DOI: 10.1002/rco2.93.

The Rise Of Padel

Picture from Temple of padel

Recently I have treated many patients who play padel and got injured. I think padel is definitely the latest 'flavour' of the month.

What is padel? It is a sport played with rackets that combines elements of tennis and squash. It takes place in an enclosed court (pictured below) about one third the size of a tennis court. Similar to squash, players can bounce the balls off the walls of the court allowing for rebounds. 

Picture from Demeco et al (2022)

Padel was invented in 1969 by *Enrique Corcuera when he and his wife Viviana were in their new vacation holiday home in Acapulco, Mexico. To pass time, the wealthy couple began throwing a ball at the wall and Viviana quickly fell in love with the easy version of the game. Enrique got builders to build a 20m by 10m cement court against the backdrop of the Pacific ocean. 

The court was closed completely to prevent the balls from falling outside due to the unpleasant memory Enrique had while attending boarding school in England. He said he suffered from being in the cold while looking for balls that fell outside the school court.

Over time glass walls and artificial turf replaced the concrete so spectators could watch the game.

Padel racquet picture from Decathlon

Played mostly in doubles (although singles can be played), with solid stringless racquets(above) and a similar tennis ball but with less pressure. Players serve underarm and the ball must bounce once before being returned. The scoring system is similar to tennis.

From the patients that I have seen, there has been little evidence of play patterns and training regimes. It is a high intensity intermittent sport with less demanding requirements when played in recreational settings, which can hide the risk of injury.

The majority of padel injuries I have seen are mostly in the lower limbs. Padel players usually have to shift their stance and require strong leg power to shift the upper body quickly. Achilles tendon injuries and ankle sprains are common when the patient executes a quick change in direction.

There were also upper limb injuries affecting the shoulder and elbow. This is not surprising due to the nature of overhead strokes (e.g. smashes). Since the court is smaller, this increases the frequency of shots taken. This greater repetition of the abduction-extention movements of the arm would explain the upper limb injuries.

A Swedish study (Thornland et al, 2021) suggested that the smaller size court along with the proximity of the players, the size and speed of the ball and the unpredictability of ball bounces would increase the risk of injuries.They proposed the use of protective eyewear.

Viviana Corcuera believes padel took off quickly because it can be enjoyed by the entire family. Grandparents can play with their children and grandchildren which brings the family together. There are estimated to be over 30 million players worldwide. 

Perhaps padel may even surpass Hyrox in terms of popularity in Singapore. This is my prediction for this year. Let's see ....

References

Demeco A, deSire A, Marotta N et al (2022). Match Analysis, Physical Training, Risk Of Injury, Risk Of Injury And Rehabilitation In Padel: Overview Of The Literature. Int J Environ Res Public Health. 19:413. DOI: 10.3390/ijerph19074153

Thornland C and Jakobsson G (2021).  Eye Injuries Related To Padel. Lakartidningen. 118:21001. PMID:34156668

*In the 1960's and 70's, Acapulco was a major destination for Hollywood's stars and that is probably where padel's popularity with celebrities began. Even the American diplomat Henry Kissinger played when he visited as did many high profile visitors. Prince Alfonso developed a passion for the game in 1974 after holidaying with the Corcueras. He built 2 padel courts in Marbella, that's how the game crossed the Atlantic.

David Beckham, Serena Williams and even French President Emmanuel Macron consider themselves fans of padel. Meanwhile in sunny Singapore, Ronaldo and two of our ministers share a padel moment.

Picture from the Daily Mail