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

Inspired Or Pissed?

I am sure most track and field fans have been following the ongoing USA Olympic Trials. Leading up to the trials, there was a fair bit of of discussion about 1500m runner Eric Holt.

Holt (who is 29) ran his fastest 1500m race at the New York City Grand Prix on 8-9 June, finishing 2nd behind Jake Whitman, the 2022 world champion. 

He was interviewed after the race and unlike many other runners he had no sponsorship, calling himself an amateur. He pays for his own running gear and physiotherapy sessions.  That interview led to an article about him in the Washington Post. He worked 13 hour shifts in a psych ward to make ends meet, where he prevents patients from harming themselves. The running team he trains with found him when he posted his extremely hard workouts on Strava between 11 pm and midnight.

Besides living with his parents (which he was feeling embarrased about), his girlfriend also pays for their meals when they do go out. He dreams to be a professional runner and promises to return the favor if he gets sponsored. He wants to prove to sponsors that he is hard working and talented, and that he's not some schmuck (foolish).    

He ends the interview by saying that he's gambling and betting his life, sacrificing everything to be a pro one day.

I thought that was really inspiring since I ran cross-country and track and field in seconday school and can identify with Holt. However, there were other running fans who saw the same interview but had a much different view. 

You can watch a profanity laced video of another track fan berating Holt for his 'sob' story. He thinks Holt should quit running and get another job. He even criticized people like me who would encourage athletes like Holt.

If you watched the critique video, please share your reaction in the comments. There is no right or wrong answer, I am just curious to hear your views.

Today is the last day of the trials. Sadly, Holt did not qualify for both the 800m or the 1500m, but at least he got Puma as a shoe sponsor now.

Thank you for reading and thanks in advance if you share your thoughts in the comments.

Rehab Is Like Snakes And Ladders

I am currently treating a few patients after they have had surgery. A patient with knee partial menisectomy and microfracture surgery, 2 with back surgery and 3 with ankle fractures that needed pins, rods and plates for stabilization.

All of them had some form of setback whilst recuperating. Kind of like playing snakes and ladders. Often we are very eager to roll a 6 on the dice and get a quick ride up the longest ladder on the board. We all want some shortcuts to win and in their cases get back to full training/ competition or living a 'normal' life as quickly as possible.

However, lurking near those big ladders are the big snakes that can send you all the way back down to the lowest level on the board.

That's the risk you take and 'punishment' associated with trying to go too fast with rehab and taking shortcuts. Short term gain often leads to frustration and long term failure.

Granted there are those who will, on occasion, roll lot's of 6's, goes quickly up the long ladders while avoiding the snakes and win. They are very rare though and that should not be our strategy when we start rehabilitation after surgery.

What's the best game plan? Rolling 3's and 4's steadily and steadily make our way up the board. If you get a big ladder great, if not a small one helps or even a small snake. These little wins and losses are not too beneficial nor too detrimental to the overall recovery plan. You will eventually get to the top of the board.

So, do not be seduced by the long ladders because there is always a bigger snake ready to take you all the way back down if you start to gamble on quick fixes over the steady approach.

Slow and steady is the way to do it. You will eventually get to the top of the board.

Does Eating Just Before Sleeping Make You Fat?

My elder son (pictured above) is on a muscle building spree. He's been trying to strength train while eating lots of protein. I've also mentioned to him that consuming protein right before sleeping would lead to greater improvements in muscle strength and muscle size. 

When he was 9 in 2019

He then mentioned that he had watched videos on Tik Tok that suggested that eating just before sleeping will make one fat. 

Is that what you think too? That eating before sleep makes you accumulate fat because you are resting for many hours after you eat. Well, let me show you that this is untrue. Note that this is with pre-sleep protein consumption. 

Data from men and women show that consuming protein pre-sleep does not change overnight fat metabolism (breakdown of fats to be used as energy). When research participants consume either caesin protein (found in milk, cheese and yoghurt) or a non caloric placebo, there was zero difference in the overnight fuel use or energy expenditure. There was also no difference in the amount of fat liberated from the fat cell measured with a technique called microdialysis.

This may be a big surprise to you as it is often thought that eating before bed will inhibit fat metabolism. Now you know it is not true. Protein consumption helps improve strength, recover from strenuous exercise as well as maintain and improve metabolic and structural health. Evidence suggests that the average person should consume 1.2 grams of protein per kilogram of body weight per day. Athletes should consume closer to 2 grams per kilogram of body weight.

Pre-sleep protein has also been found to decrease next morning hunger. Adequate protein consumption also promotes satiety, leading to a reduction in over-eating.

Plant protein my son consumes

What type of protein should you eat before bed? Recent literature suggest no difference in muscle recovery after pre-sleep consumption of dairy/ animal or plant-based (rice/pea) combination as long as enough of each is consumed. It also comes down to dietary preference. Most of the earlier research used whey or casein proteins due to a high leucine (thought to trigger growth) content. 

Whey and casein protein were more popular previously due to their ease of digestion and availability. Especially since plant based protein were not so easily available then and they cost more. Most pre-sleep protein research uses casein followed by whey protein since plant-based protein has less leucine. A greater amount of plant-based protein is needed to be consumed to elicit the same response compared to a lower amount of animal-based protein.

Hence pre-sleep protein consumption does not make you gain fat. Now you know.

References

Allman BR, Morrisey MC, Kim Js et al (2020). Lipolysis And Fat Oxidation Are Not Altered With Presleep Compared With Daytime Casein Protein In Resistance-trained Women. J Nutr. 150(1): 47-54. DOI: 10.1093/jn/nxz186.

Kinsey AW and Ormsbee M (2015). The Health Impact Of Nighttime Eating: Ols And New Perspectives.Nutrients. 7(4): 2648-2662. DOI: 10.3390/nu7042648

Saracino PG, Saylor HE, Hanna BR et al (2020). Effects oF Pre-sleep Whey Vs Plant-based Protein Consumption On Muscle Recovery Following Damaging Morning Exercise. Nutrients. 12(7): 2049. DOI: 10.3390/nu12072049.

Snijders T, Trommelen J, Kouw IWK et al (2019). The Impact Of Pre-sleep Protein Ingestion On The Skeletal Muscle Adaptive Response To Exercise In Humans: An Update. Front Nutr. 6(16). DOI: 10.3389/fnut.2019.00017.

Understanding The Recovery Of The Intervertebral Disc

Picture from Wikipedia

I came across a recent paper (Feki et al, 2024) about the positions which help our intervertebral discs recover and heal when we sleep. I have written at least 5 articles on intervertebral discs. This is definitely still a topic that I get questions from most often among my friends and patients alike. Almost every single one of my friends and patients are fearful of having a 'slipped intervertebral disc' whenever they have low back pain (LBP). The intervertebral discs (IVD) have a really bad reputation for causing significant pain and disability in many people.

Here's a quick review if you did not read those 5 articles.

The IVD consists of a very tough outer layer called the annulus fibrosis (AF). It is made of of several layers of fibrocartilage consisting of Type I and II collagen fibers. The AF protects the soft, gel-like substance in the middle known as the nucleus pulposus (NP). The NP helps distribute pressure evenly across the IVD and prevent excessive forces on the spine.

See how thick the AF is from the picture above? Here's something else you need to know. There is a cartilaginous endplate between the AF and the vertebra (the spine). The endplates hold the IVD in place. It allows load to be spread evenly and to provide attachment to the IVD. This creates a super strong connection to the AF making it impossible for the IVD to 'slip' out of position.

Yes, our discs are actually very strong and hardy. How strong are our IVD's? In a published study on thoracic discs in the young (28 years old plus minus 8 years) , it took about 740 pounds of force to compress the disc height 1 mm. For the older subjects (70 years young plus minus 7 years), it took almost 460 pounds of force. Note that these are on cadavers with the muscles and bones cut away (Stemper et al, 2010).

The IVD's withstand a whole variety of complex forces in our daily activities and also when we exercise. This can lead to significant structural changes in terms of volume, area and height of the intervertebral disc. It can lead to an increase in disc stiffness and a decrease in interdiscal pressure.

In order for your discs to remain healthy and strong, it is dependent on a recovery phase which serves to prevent premature disc degeneration. This happens during a period of nocturnal rest i.e. when you sleep at night.

This phenomenon of disc recovery has been documented extensively through many studies using MRI and intradiscal pressure measurement. Fluid dynamics (water content) within the disc are considered a primary factor in recovery, while it's intricate multiscale structure and viscoelastic (behaving with both liquid-like and solid-like) properties also play key roles.

Feki et al (2024) in their review collated, analyzed and evaluated the existing in vivo (human) and in vitro (in controlled environments) on this topic to provide a comprehensive understanding of this recovery process to enable future advancements in medical treatment and biomedical enginerring solutions to enhance the natural recovery processes of intervertebral discs.

As it is a very long (and complex) review article (Feki et al, 2024), I am simply highlighting the optimal recovery positions (pictured below) for intervertebral disc rehydration. 

Picture from Feki et al, 2024

(a) prone (b) modified press up/ push up position (c) supine with under knee and back support

(d) and (e) side lying with lumbar flexion with pillows between legs

(f) and (g) side lying with and without manual distraction

(h) 50 degrees gravity assisted position (i) 110 degrees supported sitting

(j) inclined sitting with lumbar support

So, you see from the pictures that some of the supposedly 'poor' posture/ positions you were told, are actually good for your intervertebral discs.

References

Feki F, Zairi F, Tamoud A et al (2024). Understanding The Recovery Of The Intervertebral Disc: A Comprehensive Review Of In Vivo And In Vitro Studies. J Bionic Eng. DOI: 10.1007/s42235-024-00542-2

Fournier DE, Kiser PK, Shoemaker JK et al (2020). Vascularization Of The Human Intervertebral Disc: A Scoping Review. JOR Spine. 15: 3(4): e1123. DOI: 10.1002/jsp2.1123.

Stemper BD, Board D et al (2010). Biomechanical Properties Of Human Thoracic Spine Disc Segments. J Craniovert Junct Sp. 1(1): 18-22. DOI: 10.4103/09774-8237.65477