Atrophy of medial head of the gastrocnemius – muscular and nerve disorders forum – ehealthforum la gas prices 2016


I am 28 years of age and a full-time Fitness Instructor and PT. I have always been very active and taken part in many different sports and activities. I started training for The London Marathon November last year. Training was going fine and in January this year I started to increase the distance in training. I then noticed my calf muscle on my left leg was significantly smaller than the other. I had no pain at all so I presumed I was favouring one side of my body more than the other so I kept running. I went to see a Physio just to get a 2nd opinion and he could find nothing wrong and said to just reduce the number of running sessions from 4 to 3 per week.

On the Marathon Day I got to 18 miles and my right hip flexor became very strained to the point where I was unable to continue. The hip flexor is fine now, but the calf has not returned. It is the Medial Head of the Gastroc that has atrophied. I went to see my GP and was referred to St Georges to the Nurologist. I have had an MRI on my lower back, which displayed a slight bulge on my L5/S1 disc, but nothing that could affect the Calf muscle. I have also had an EMG surface and intra muscular test carried out and all nerves are functioning fine. I am still awaiting an appointment to have an MRI carried out on the calf muscle, but I feel this is all taking a long time.

The injury is getting me down. I have tried calf strengthening exercises and stretching, but nothing has helped. I am limping slightly when I walk and my whole left leg and glute always feels stiff. If anyone has had a similar injury or has any knowledge in this area and could help that would be very much appreciated.

It is interesting that it involves just the medial head of the gastrocnemius, and not any of the rest of the triceps surae muscle (soleus or plantaris). The gastrocnemius is innervated by the tibial nerve (derived from L4-S3 nerve roots, the tibial nerve is the larger of the two terminal branches of the sciatic nerve. It leaves the popliteal fossa between the heads of the gastrocnemius and supplies all muscles in the posterior compartment of the leg).

You would think, that because just the medial head is involved, there would have to be a lesion in the tibial nerve just as it branches to innervate the medial head. That something is compressing the nerve at that location, be a mass, fascial band of tissue, scar, whatever (which is the reason for the MRI of the knee and calf). But, with normal EMG and NCV (nerve conduction velocity) tests, this is probably not as likely.

As to strengthening of the muscle, you would think that since the electromyography shows that the muscle is receiving impulses from the nerve and the muscle fibers are behaving normally, that you should be able to rebuild the strength in the muscle. It just does not make sense.

Again, from your presentation, the only thing that makes any sense is a lesion in the tibial nerve, supplying the medial head. But, with normal electrical studies, this is indeed a very perplexing problem. Maybe the MRI of the knee/leg will reveal something.

A few totally off-the-wall thought that have come to mind include MS (multiple sclerosis), polio, ALS (amyotrophic lateral sclerosis), or CMT (Charcot-Marie-Tooth). But, you have probably been vaccinated against polio, so that is probably out. One of the hallmarks of MS is neurological symptoms that do not make sense. But, just part of one skeletal muscle involvement would not be a typical presentation for any of these conditions. Again, these are just off-the-wall thoughts.

Try to not get discouraged. It is very difficult, especially when the cause of the problem cannot be found. Continue to work on strengthening as much as possible and maintain the range of motion in all of your joints. If you have access to a pool, you might find water exercises very enjoyable and helpful. In some pools, they have a weighted vest so that patients can “run” in the deep end of the pool. This is a common way for athletes to stay in shape when they have a lower extremity injury. Just something you might want to look into.