Sunday, July 27, 2025

What Helps Prevent Muscle Atrophy During Immobilization

Which leg was immobilized?
We see many patients with muscle atrophy on their affected limb. This definitely happens after surgery where whole body or single limb immobilization may be necessary. This leads to decreased muscle size and strength.

What strategies are there to mitigate this? You may be very surpised.

20 male participants (average age 33) took part in this study (Labidi et al, 2024). All were former competitive athletes, primarily in athletics, now working as fitness coaches. 

The participants were split into 2 groups. They had 2 weeks of single lower leg immobilization with a orthopaedic walking boot . They were taught to use crutches and instructed not to weight bear on that leg. This was followed by 2 weeks of supervised rehabilitation before return to sport (RTS). 

The participants underwent 4 weeks of a standardized training program to ensure a common training base before the immobilization procedure. There were 5 sessions (3 resistance, 2 endurance) of training each week. They also received 4 nutritional sessions inclusive of face-to-face consults with a nutritionist and educational videos to standardized daily energy and protein intake throughout training, immobilization and rehabilitation phases.

Picture from SIU Med
The participants then underwent 4 weeks of supervised training. The 1st group had whole body heat therapy (HEAT) while the 2nd group had sham treatment (SHAM) throughout the immobilization and rehabilitation periods.

During the immobilization period, the participants received 11 passive interventions of 60 minutes. The HEAT group sat in a heat chamber at 48 to 50 degree celcius at 50% relative humidity (at 0 m altitude). 

During the rehabilitation period, the participants received 5 active interventions (conditioning) of 60 minutes. The HEAT group performed the sessions in the heat chamber at 35 degrees Celcius and 60 degress relative humidity at 0 m altitude. 

The SHAM group sat in an altitude chamber, set at only 200 m (to create a placebo effect while avoiding any effect of altitude). The temperature was at 24 degree celcius and 40% relative humidity.

Ready for the results? All of the following were measured pre-immobilization, post-immobilization and at RTS. Muscle strength (isometric and isokinetic) were measured. Muscle volume was measured by MRI and ultrasound while muscle biopsies were also obtained. Maximal isometric strength for the calf muscles (plantarflexion) was lower at RTS compared to pre-immobilization in SHAM. 

Isokinetic strength during a fatigue test was higher at RTS compared with pre-immobilization in HEAT but not SHAM. 

Shape of muscle and muscle thickness were lower at post-immobilization compared with pre-immobilization only in SHAM. Cross sectional area of the soleus and the medial, lateral gastrocnemius were decreased in SHAM. Only the medial gastrocnemius was smaller in cross sectional area in HEAT.

The results indicate that using heat therapy during immobilization and rehabilitation reduces muscle atrophy and maintains calf strength in healthy humans. Repeated heat exposures should be considered to counteract muscle atrophy during immobilization.

I'm not sure that it's practical to get in a sauna with a cast on but maybe with a boot or back slab that can be removed temporarily? I would do it if I wanted to return to sport badly enough or maybe if I'm old and wanted to prevent muscle bulk and strength while awaiting healing to happen. For those with with an aversion to heat, definitely no go.

Reference

Labidi M, AlhammoudM, Mtibaa K et al (2024). The Effects Of Heat Therapy During Immobilization And Rehabilitation On Muscle Atrophy And Strength Loss At Return To Sports In Healthy Humans. Orth J Sp Med. 12(10). DOI: 10.1177/23259671241281727

Sunday, July 20, 2025

Our Words Affect Pain

Picture from Coregymball
It may be just words you think. Perhaps not. Recently published fascinating research suggest that how healthcare providers describe an injury can have a direct impact on a patient's pain

Not only were the patients blinded (a technique used to minimise bias), the patients also did not know they were part of a study.

Picture from article
50 recreational runners with Achilles tedinopathy took part in the radomized trial (pictured above). They ran 3 times a week. Runners in the experimental group received diagnostic information of tendon pain that highlighted reversible changes in muscle function as their primary problem. They did not hear any reference to tendon pathology.

The control group received an explanation of tendon pain that prioritised irreversible structural tendon pathology as the cause of pain.

The primary outcome measure was how much pain the runners had during a standardised hopping task measured on a scale of 0-100. Secondary outcomes were how stiff the lower limbs were hopping and time in seconds for pain to ease after completing the hopping task.

The diagnostic information immediately affected pain intensity during the hopping task. The average pain score was 25.4 in the experimental group versus 36.7 in the control group.

Time to ease (no pain) after hopping was near identical in both groups. Lower limb stiffness was higher in the experimental group. Note that higher leg stiffness is better for leg hopping because increased leg stiffness allows for greater force production and more efficient energy transfer. This leads to higher jump heights and faster movement.

This is a really intriguing area of research. We now have data showing that information from healthcare providers during the first visit has an immediate effect on pain. The language we use during clinical interactions can be powerful, shaping our perceptions and pain responses. This knowledge should change how we interact with our patients. 

However, we need to also be able to do this in our clinics without compromising the accuracy and necessary medical information.

Reference

Travers NJ, Travers MJ, Gibson W et al (2025). The Content Of Diagnostic Information Has An Immediate Effect On Pain With Loading In People With Morportion Achilles Tendinopathy: A Randomized Clinical Experiment. Bra J PT. 29(5). DOI: 10.1016/j.bjbt.2025.101244

Sunday, July 13, 2025

Quadrilateral Space Syndrome

R posterior arm picture by Mickeymed.com
I treated an 11year old girl recently with pain in her quadrilateral space. What space you may ask? The quadrilateral (or quadrangular) space is a tiny window or space that the axillary nerve and other blood vessels (posterior circumflex humeral artery) exit from the shoulder to the back of the arm. It's boundaries are teres minor on top, the humerus (arm bone) on the right, teres major below and the long head of triceps on the left. The axillary nerve supplies the deltoids and the teres minor muscles. 

Picture from Clinical Anatomy & Op Surgery
This young patient plays softball for her school and is her team's first choice pitcher. Softball pitching is different as the ball is thrown to the batter using an underhand motion. The goal while pitching is similar to baseball, to get the batters out by strikes or preventing them from reaching base. 

Injury or compression in the quadrilateral space often leads to pain, numbness in the posterior shoulder/ arm and/ or weakness in those areas.

This condition is much more common in young athletes participating in arm over head sports like swimming, throwing and volleyball in their dominant hand. But she did do many overhead throws prior to having this pain in her posterior shoulder and arm. In addition, her coach also started her on a weight training program in the upper body and arms.

Injury or compression in the quadrilateral space often leads to pain, numbness in the posterior shoulder/ arm and/ or weakness in those areas. There is often tenderness in the quadrilateral space on palpation. 

My patient also had some paresthesia (numbness, tingling sensations) on the outer shoulder and elbow when I checked her upper limb tension test. Her shoulder external rotation strength was also noticeably weaker on her thowing arm, which should not be the case.

Once we determined the cause, treatment was easy as we simply had to 'widen' the quadrilateral space while also addressing the overhead throwing overuse and the sudden increase in weight training. A simple phone call to her coach,who happened to be a previous national pitcher and patient of mine solved that.

Reference

Pocellini G, Brigo A, Novi M et al (2025). Different Patterns Of Neurogenic Quadrilateral Space Syndrome: A Case Series Of Undefinied Posterior Shoulder Pain. J Orthop Trauma. 26(1). DOI: 10.1186/s10195-024-00813-y.

Sunday, July 6, 2025

3 Common Sites Of Musculotendinous Junction Injuries

I recently had a patient with a musculotendinous junction injury. Also known as the muscle-tendon junction (MTJ), it acts like a bridge to transfer forces from the muscle via the tendon to the connecting bone the muscle attaches to. This allows for movement to take place. 

It is a special area where the muscle's fascia connects and inersects with tendon tissue. Structurally, the MTJ is seamlessly integrated into the tendon, with finger-like folds increasing the surface area for a stronger connection and to distribute stress (pictured above).

It's a common site for injury as the MTJ undergoes some stress during daily activities and substanstial stress while playing sports. MTJ injury is often accompanied with both muscle and tendon injuries leading to restricted force trasmission.

Due to it's highly specialized structure, it does not often heal well after injury. Conservative treatment are mostly effective for minor MTJ sprains while partial tears and complete ruptures will require surgical intervention.

It can happen during a fall leading to trauma to the area. It often occurs due to repeated overload, usually from high intensity training in young athletes or overuse in middle age or older adults. My observations are MTJ injuries usually happen after a period of rest/ decreased muscle use followed by a period of intense muscle activity. 

An example who be my patient mentioned above. He went on holiday for 3 weeks with no exercise and resumed his weekly basketball game on returrn and promptly tore his hamstrings at the MTJ. These tears occur frequently during eccentric muscle loading. 

They are usually complete muscle tears. In hamstring injuries this account for 14.4% of all bicep femoris injuries. The supraspinatus muscle has the highest incidence of the tendon midsubstance injuries (11.4%). Complete tendon avulsions are more frequent in the triceps brachii and pectoralis major.

Conservative treatmant options like rest, ice and compression etc helps in the initial stages if the tear is small. Several studies have indicated that surgical treatment yields better results in terms of function, strength, patient ratings and recovery to pre-injury performance for the more serious tears.

Continous development of tissue engineering that focuses on regenerating new tissue from cells are now helpful to MTJ injuries by utilizing biological and synthetic scaffold-based tissue. This helps in the repair and healing of MTJ tears. However it is not easy to fully mimic the unique characteristics of our muscles, tendons and the MTJ itself.

Hopefully, newer polymers and scaffolds will help with healing of MTJ injuries in the future. For now, please be vigilant in your exercise after a period of rest. Avoid exercising at higher intensities initially while allowing for your muscles to adapt again. Note that the calf, pectoralis major (chest) and hamstrings are the most vulnearble areas.

Reference

Tong Sm Sun Y, Kuang B et al (2024). A Comprehensive Review Of Muscle-Tendon Junction: Structure, Function, Injury And Repair. Biomedicines 12, 243. DOI: 10.3390/biomedicines12020423