May The (Knee) Forces be With You

Picture from Hart et al, 2022

We were discussing the knee joint in our clinic this past week. Meaning ALL the conditions that can cause pain in the knee. Patellofemoral joint pain, patella tendinopathy, MCL, ACL injuries, fat pad irritation, torn meniscus etc. 

In order to understand knee joint injuries, we need to know what can increase load or amplify forces in the knee joint. An increase in joint forces can increase symptoms when one has patellofemoral pain (PFP) so it will be most helpful to know what activities may influence patellofemoral joint reaction forces (PFJRF).

Picture from Dr JT Andrish

So happened that I came across an article explaining how PFJRF compares across different activities and interventions.

intercondylar notch

PFJRF is created by tension (or forces) in the quadriceps and patella tendon which moves the patella into the intercondylar (pictured above) surface (of the femur). It can increase due to greater quadriceps muscle force or when there is an increase in knee flexion (or knee bending).

The article (systematic review) examined PFJFR in daily activities, exercises, interventions (treatment). It also compares healthy individuals to those with PFP or osteoarthritis (OA).

A total of 71 articles were included in the systematic review. Approximate PFJRF for healthy individuals during various activities are pictured below where BW = body weight. 

Knee joint forces in healthy individuals

As you can see, activities that involve greater knee flexion or greater external load resulted in higher PFJRF. For example a deep squat with a heavy weight.

An increase in knee flexion can increase the contact area (in the intercondylar area) and may therefore reduce patellofemoral contact pressure. The authors felt this would be the case in a knee that is "normally aligned". However, certain movements during loading such as increased hip adduction (pictured below) and/ or internal rotation may reduce contact area and increase contact pressure.

Increase in hip adduction in picture A

The authors reported that there were no discernible differences in peak PFJRF during daily activities between healthy individuals and those with PFP/ OA.

There are 3 options if you have knee pain and we need to reduce PFJRF. Reduce knee flexion/ bending during loading. Reduce external load. Reduce hip adduction/ internal rotation during loading.

So if you are weight training by doing a squat and your knee hurts. You can squat less (70-80 degrees) and / or using a lighter weight. Preferably with less hip adduction too. 

In running we can apply this by increasing step rate/ cadence to reduce patellofemoral load. Smaller, quicker steps reduces knee flexion and hip adduction during the stance phase of running. Or better still make your gluteus medius, hamstrings and calf muscle a lot stronger.

Note that the goal is to reduce load only when symptoms are present and the knee is irritated. You can gradually increase load again when able. For other clinicians and physiotherapists reading this, a progressive approach is needed and utimately it will be your patient symptoms and goals that will guide you.

Do note that the exact link between PFJRF and knee pain is complex and the lack of difference between those healthy inviduals without knee pain and those with PFP/ OA draws attention to this. 

The authors also mentioned that when articular cartilage is underloaded (not enough load), it may be an issue too. 

Reference

Hart HF, Patterson BE, Crossley KM et al (2022). May The Force Be With You: Understanding How Patellofemoral Joint Reaction Force Compares Across Different Activities And Physical Interventions- A Systematic Review And Meta-Analysis. BJSM. 56: 521-530. DOI: 10.1136/bjsports-2021-104686

Bioelectrical Impedance To Measure Body Fat?

BIA from Weightology

Last week, my helper's cousin asked me for suggestions with regards to measuring her body fat levels. Her cousin was about to sign up with a personal trainer  and he wanted to measure her body fat levels before they started. Of course that came with a cost before the training even started.

Picture from Bodybuilding Wizard 

I told my helper the most accurate method would be hydrostatic underwater weighing (or underwater weighing) which was very dificult to do (pictured above). I only did it as a physiotherapy student while doing the exercise physiology module in year 1. Next best was using callipers to measure the sum of 7 skinfolds (pictured below).

However, my helper said the trainer suggested using bioelectrical impedance analysis (BIA) to measure her cousin's body fat levels.

Bioelectrical impedance is a popular way to measure body fat levels. It is also practical  as it takes a relatively short analysis time. It is not invasive at all and it is available commercially at an affordable cost.

BIA measures body composition based on the rate at which an electric currrent travels through your body. Body fat (adipose tissue) causes greater resistance (impedance) than lean mass (muscle) and slows the rate of electric current traveling through the body. Based on that rate and your height, gender and weight, your body fat levels, fat free mass etc are calculated.

However, BIA is not accurate at all for determining body fat levels. A recently (Aug 2024) published study showed that all 3 BIA devices tested significantly underestimated body fat levels.

28 firefighters were evaluated using 3 BIA devices. A multifrequency BIA hand-to-foot device, a single frequency BIA foot scale and a single frequency handheld BIA device. These were measured against dual x-ray absorptiometry (DEXA) for comparison (Jagim et al, 2024).

All 3 BIA devices significantly under measured body fat levels. Errors ranged between 4 to 5.5 percent when compared to the DEXA scans. Despite it's ease of use and practicability, BIA should not be used to assess body fat levels.

If you do or if your trainer insists on using BIA, bear in mind that they are not accurate, but you can still use them to track changes over time. 

Picture from Topendsports

I would suggest using the sum of 7 skinfolds if you want to track your body fat levels rather than BIA as it would be more accurate. The callipers are also not expensive. The following locations are commonly used. The abdomen, pectoral area, mid axilla, subscapular area, quadriceps, suprailiac area and the triceps.

There is more to health than your body fat percentage or weight. These measurements are not a reflection of your general well being. 

Reference

Jagim AR, Luedke J, Erickson JL et al (2024). Validation Of Bioelectrical Impedance Devices For The Determination Of Body Fat Percentage In Firefighters. J Strength Cond Resc. 38(8): e448-453. DOI: JSC.0000000000004809. PMID: 39072665

Rock Climbing Injuries

Zi Yun competing

This is the second time rock climbing is contested at the Olympics since its debut at the 2021 Tokyo Olympics. For those who are not familiar, the three climbing disciplines include lead climbing, speed climbing, and bouldering. They are designed to challenge endurance, speed, and power, respectively.

Climbing gyms in Singapore has more than doubled since 2018, with nearly 40 climbing facilities now available. Contrary to popular belief, climbing is not only a physical sport that emphasizes on strength and technique, but also a test of mental tenacity. It demands problem solving skills, focus, composure, and resilience, whether you are a serious climber or just climbing recreationally. 

In a study on 436 climbers, 77.1% of the injuries affected the upper extremities, 17.7% lower extremities and 5.2% other body regions (Lutter et al, 2020). The most frequent injuries were finger pully injuries and finger tenosynovitis.

Bouldering has caused more acute injuries than rope-protected climbing. There are more knee injuries and shoulder dislocations. Young climbers were found to have more finger growth plate injuries.

There were also higher incidences of upper extremity injuries in bouldering (Kovářová et al, 2024). especially to the hands, fingers, wrists, and elbows.

Lead climbers had a broader range of injuries, including head, shoulder, and foot related injuries.

Traditional climbing (done outdoors in the natural environment) often results in more severe injuries involving long falls. Interestingly it's not personal characteristics (gender, age, weight or height) but human factors like concentration and fatigue that had significant impact on the number and severity of injuries  (Kovářová et al, 2024).

Just like other sports, if you increase your climbing intensity too quickly, have large muscle strength imbalances and rest insufficiently, you have a much higher chance of sustaining an injury. Many climbers do not rest or stop due to a fear of losing strength, leading to a decline in performance.

According to published studies, only 36% of injured climbers seek medical help. While some injuries were unavoidable, many were caused by the climbing culture of training with injuries and disregarding the need for recovery. This issue is compounded by insufficient knowledge on training and recovery, and ignorance. Many climbers also take injuries lightly and try to return to climbing too quickly.

However, you do not always have to completely stay off the wall or away from climbing related activities to recover. Modifications and other compensatory mechanisms can be done to your climbing session to achieve the same results. 

In order to attain climbing longevity, climbers need to be aware of the risks they are taking  and maintain appropriate recovery measures. If you are injured and unsure on how to go about your training, do come and see us for a thorough assessment, we will plan your treatment according to your concerns and goals. We promise to do our best to get you back strong on the wall as soon as possible.

*This week's post is written by Zi Yun (paper cloud), one of our new physiotherapists. She is a super rock climber. She wins most if not all the local rock climbing competitions and more. Having started climbing seven years ago, she has encountered many climbing related injuries and can defintely treat you if you are injured. Above pictures by Zi Yun.

References

Kovářová M, Pyszko P, and Kikalová K. (2024). Analyzing Injury Patterns in Climbing: A Comprehensive Study Of Risk factors. Sports, 12(2), 61. DOI: 10.3390/sports12020061

Lutter C, Tischer T, Hotfield T et al (2020). Current Trends In Sport Climbing Injuries After The Inclusion Into The Olympic Program. Analysis of 633 Injuries within the years 2017/18. Mus, Ligs Tendons J. 10(2), 201. DOI: 10.32098/mltj.02.2020.06

Science, Pseudoscience And Superstition At The Olympics

Picture by Greg Martin

If you stayed up to watch the opening ceremony of the XXXIII Olympic Games in Paris, you would have witnessed the historic boat parade down the River Seine. This display was the first time the Olympic opening ceremony was staged outside the main stadium, making it the biggest ever launch for the greatest sports show on earth.

Alas, that gamble made 300,000 people who lined the river banks very wet from the torrential rain as the athletes went past the Effiel Towel, the Lourve and the Notre Dame Cathedral.

Other than watching the games, I will be watching the athletes who continue to blend proven, unproven and even disproven strategies at the games. 

It may have all started in Beijing, 2008 when Kinesio Taping donated more than 50,000 rolls of kinesio tape to athletes and sports teams at that Olympic games. You would see kinesio tape on body parts of athletes in many televised sports especially beach volleyball (pictured below) and track and field (pictured above). That exposure catapulted Kinesio Taping to the big time. 

Many subsequent studies showed no evidence of 'improved lymphatic drainage', no decreased risk of injuries etc. But most if not all of the reviews and meta-analyses were done by researchers not trained in the correct taping techniques. Some researchers outright rejected offers to show them the proper taping techniques. 

Of course there were many research papers showing Kinesio taping works if done correctly. These were conducted by researchers who have learnt the correct taping techniques.

In 2016, Michael Phelps 'poisoned' the pseudoscience well with large purple bruises across his back and shoulders while adding 5 gold medals to his haul. Cupping therapy was the next big thing for recovery as demonstrated by Phelps, who later launched his own cupping device in 2023. 

Also popular are cold (ice) water immersions for recovery. Mo Farah, the British Olympic gold medalist who famously won 4 gold medals at the 2012 and 2016 Olympics in the 5,000 and 10,000 metres made cold water immersions a regular part of his recovery as he was convinced that it would reduce inflammation. The opposite was true since cold water immersions after hard exercise suppressed signaling pathways associated with recovery for several days. At best, it is just perceived benefits on muscle soreness, although it does help reduce pain.

Other than pseudoscience (termed by Novella, 2016), there are are undertones of superstition too. If you watch Rafa Nadal's  rituals (above) like how he places his bottles with labels facing the sides he plays and always letting his opponent cross the net first during changovers etc.

Sha'carri Richardson, who won the 100m at last year's world track and field championships always prays and acknowledges with her fingers before the start (pictured above).

We know that rituals and superstitions do not work to make one run faster, jump higher or throw further. They may however, give athletes a form of control and subsequently confer a performance advantage. 

Having worked with athletes and going to 2 Olympics in the past, I can say that elite athletes are a stubborn lot. They have immense determination and will not quit even when sick or injured. I will not mention some of Team Singapore athlete's rituals and superstitions.

Definitely true that science, pseudoscience and superstitution are connected at the highest sporting levels. Pseudoscience is lucrative and thriving as it extends into society with tik tok health experts/ gurus, fitness influencers and snake oil salesmen. They will not have a nuanced understanding of the science nor their audiences' best interests at heart. 

Of course there are also athletes who are also driven by data, power output stroke rate, stride length and other metrics that can be recorded with modern technology. 

Our clinics will try, through our practice, readings and treating our patients, to sort out the science from the pseudoscience and we'll let you know.

Let's watch the Olympic Games!

Reference

Novella S. (2016). Cupping- Olympic Pseudoscience. Science-Based Medicine (August 10). Online at https://sciencebasedmedicine.org/cupping-olympic-pseudoscience/

Sural Nerve Pain

I recently saw a patient who had pain resulting from her sural nerve. Let me go through a little about the anatomy and location of the sural nerve.

The sural nerve sits superficially below the skin's surface at the back of the calf. It is formed from the medial sural cutaneous nerve and the lateral sural cutaneous nerve.

It is usually between the medial and lateral gastrocnemius (calf) muscles, running parallel to the saphaenous vein. At the ankle, the sural nerve 'wraps' around the outer ankle near the peroneal tendons before it splits into 2 branches at the level of the 5th metatarsal.

The sural nerve is a sensory nerve, it provides sensation to the lower one third of the outer leg, outer heel and foot. It's main function is to let you feel sensation on your skin. It can also detect your foot position, temperature, pain, vibration and touch.

Since the sural nerve is positioned so superficially, it can be irritated from any muscular of fascial entrapment and sometimes from a simple outer ankle sprain. It can also be 'over stretched' from sitting too long with the foot pointed down and out or after a long driving trip. When the nerve is irritated, it can result in burning pain in the lateral shin or foot (known as sural neuritis).

A common cause of sural nerve pain is after a sprained ankle when the foot is rolled outwards quickly. This can over stretch the sural nerve causing pain over the area it covers. 

I also remember a previous patient who had very tight fitting ballet shoes with a strap over the outside ankle which compressed her sural nerve.

A lot of metal work

Another patient had irritation from her metal implants (pictured above) after orthopaedic surgery from fracturing both tibia and fibular. 

Patients may describe their pain being constantly present, made worse with activity but present even at rest. This constant pain at rest is what differentiates the symptoms of sural nerve pain from other conditions, where pain normally eases with rest.

I usually do a modified Straight Leg Raise tension test to compare both sides. The patient will tell you the affected side will worsen their symptoms. It may also be tender to touch along the path of the nerve.

Appropriate manual therapy will easily relieve and treat sural nerve pain. Mobilizing the ankle, stretching the nerve and of course treating the fascia that is putting tension on the sural nerve. 

Hot Water (Not Cold) Immersions More Effective For Recovery

Picture from Racold.com

With the Paris Olympics around the corner, many of my patients have been asking me about recovery, ice immersions and the Singapore women's swimming Olympic selection fiasco (no, I am not discussing that).  

A patient I saw yesterday mentioned that an ice immersion recovery center just opened near his home and he was hoping it will help his sore muscles.

Picture from Business Insider by Alexandre Simoes 

I told him that evidence shows that ice baths/ immersions does not help  recovery. In fact cold water immersion after hard exercise suppressed signaling pathways associated with recovery. This suppression lasted several days. In addition, ice bathing reduced the body's muscles uptake of dietary proteins, which is important for growth and cell maintenance. Grgic (2022) showed that cold water immersion reduced exercise related strength gains while (Pinero et al, 2024) showed that ice bathing immediately after weight training inhibited muscle growth.

On the contrary, hot water immersion (below) improved recovery follwing exercise induced muscle damage (Sautillet et al, 2024).

Picture from Newsmeter

Following exercise induced muscle damage, Sautillet and colleagues (2024) put 30 active males through one of the following recovery interventions : cold water immersion (11 degrees Celcius), hot water immersion (41 deg Celsius) and control group of warm-bath (36 deg Celcius).

Quadriceps maximum strength and explosive strength were measured pre, 24 and 48 hours post exercise. Pressure pain threshold (PPT), or was also measured to quantify the recovery from muscle soreness

Here are the results. 48 hours post exercise, quadriceps maximal strength returned to baseline values after both cold and hot water immersions. However, explosive strength levels and PPT (muscle tenderness) returned to baseline levels post 48 hours only after hot water immersion.

In addition, surface electromyography (electrodes) signals from the vastus lateralis (outer quadriceps) was significantly increased following cold water immersion. Meaning more muscle fatigue. Or as patients like to say, their muscles are 'very tight'.

The authors concluded that a single session of hot water immersion (rather than cold water immersion) improved the rate of explosive strength followed exercise induced damage. When explosive power is a key performance requirement, hot water immersion should be preferred over cold.

*Note that the cold bath temperature used in this study (Santillet et al, 2024) was 11 degrees Celcius. Wim Hof (the Dutch iceman), others on Tik Tok, other social media and purveyors of commercial health and wellness have different protocols.

For those who are keen the temperature of the hot bath was 41 degrees Celsius for a duration of 15-30 minutes.

References

Grgic J. (2023). Effects Of post-exercise Cold-water Immersion On Resistance Training-Induced Gains In Muscular Strength: A Meta-analysis. Eur J Sp Sci. 23(3): 372-308. DOI: 10.1080/17461391.2022.2033851.

Pinero A, Burke R, Augustin F et al (2024). Throwing Cold Water On Muscle Growth: A Systematic Review With Meta-analysis Of The Effects Of Postexercise Cold Water Immersion On Resistance Training-induced Hypertrophy. Eur J Sp Sci. 24: 177-189. DOI: 10.1002/ejsc.12074

Sautillet B, Bourdillon N, Millet GP et al (2024). Hot Bt Not Cold Water Immersion Mitigates The Decline In Rate Of Force Development Following Exercise-Induced Muscle Damage. Med Sci Sp Ex. DOI: 10.1249/MSS.0000000000003513

Can Ozempic And Wegovy Help Knee Osteoarthritis Pain?

Picture from Second Nature 

I never thought I would be reading up on Ozempic and Wegovy. I have a patient who told me he started taking Ozempic as he's trying to lose weight. They are both injected medications that contain semaglutide. Ozempic is approved (in USA) to treat Type II diabetes while Wegovy is a higher dosed version (of semaglutide) that is approved (again in USA) for weight loss.

According to results from the STEP-9 trial (by Novo Nordisk) reported at the World Congress on Osteoarthritis (OARSI 2024), Wegovy, containing peptide receptor agonist (GLP-1) semaglutide not only induced weight loss but improved knee pain in people with knee osteoarthritis (OA).

STEP-9 was a multi national, multi center phase 3 clinical trial that enrolled subjects that had a BMI of >30, a clinical diagnosis of knee osteoarthritis with moderate radiographic changes and were experiencing knee pain.

There were 407 subjects in STEP-9, randomly allocated 2:1 to receive once a week a subcutaneous injection of either semaglutide 2.4 mg or a placebo for a total of 68 weeks. Mean age of the subjects were 56 years and 81.6 percent were women. 60.9 percent were White, 11.8 percent Native American, 7.6 percent Black and 19.7 percent were of other ethnic origin.

Another finding was that the use of pain medication went down in the semaglutide group compared to the placebo group. This was maintained throughout the study.

Of course the are suggestions that the weight loss itself helped with the knee pain since weight loss fell by a significantly greater amount in the people treated with semaglutide versus those given a placebo. Weight loss was 13.7 percent versus 3.2 percent from baseline after 68 weeks.

The authors questioned if there is a specific action of GLP-1 receptor agonist on the knee joint itself and not through weight loss only. Especially since results from previous LOSEIT trial using liraglutide (also used to treat Type II diabetes) showed that subjects lost 2.8 kg versus a gain of 1.2 kg in the placebo group over a year did not have any change in the Knee injury and Osteoarthritis Outcome scores. The patients in that study had to undergo weight loss first before they were given the liraglutide.

Obesity is a worsening problem world wide in developed countries and Singapore has increasing numbers in people with diabetes. This is certainly going to add to the boom in weight loss drugs.

Morgan Stanley projects that the market for weight loss drugs will reach $54 billion by 2030, a 400 percent increase from today. Especially since so many celebrities have gushed about how much weight they have lost since taking them. Eli Lilly and Novo Nordisk (who owns Wegovy and Ozempic) together have at least 12 more obesity medications under development.

We are living through a cultural shift in which obesity is viewed as a disease rather than the result of lifestyle choices. 

Should my patient try Wegovy instead especially since he does have knee pain from osteoarthritis? Wegovy has a higher dose of 2.4 mg semaglutide versus 2 mg for Ozempic.

Will Wegovy or Ozempic be the new default recommended treatment for osteoarthritis pain instead of surgery, gel injections and physiotherapy?

Reference

https://www.medscape.com/viewcollection/37518

*Please note that the STEP-9 study was funded by Nova Nordisk and the principal investigator Henning Bliddal acknowledged that research grants were given by Novo Nordisk to his institution as well as consulting fees and honoraria. He also received congress and travel support from Contura