Calf Strain Rehabilitation
Injuries to the calf and lower leg are all too common in runners and field sports athletes. A strain is loosely defined as a muscle tear or damage which can be acute, subacute or chronic. Calf strains are different from other soft tissue/muscle strains because of the structure and function of the calf musculature. There is constant force transmission between muscle fibers and the connective tissue bands between these fibers. Collagen tissue in the calf is also different than what you would find in other muscles.
When running, 50% of your propulsion comes from below the knee. In steady-state running, the muscles in your calf are loaded up to 12.5 times your body weight. The calf is also fundamental in everything we do from walking, running, etc. It’s difficult to get out of NOT loading it.
As we age, our muscles atrophy and our tendons become more compliant (see our previous post about tendons!). Research shows that by the time we hit 30 years of age, our calf muscles begin to atrophy. Just because you run does not mean your calves are strong. Most runners I see in the clinic cannot do 25 full single leg calf raises.
Two Types of Calf Strains
When it comes to calf strains, we are dealing with two potential injuries - a strain to the gastrocnemius (the major bulk of your calf) or a strain to the soleus (the deeper layer of the calf). Both of these muscles come together to form the Achilles tendon which attaches at the calcaneus, or heel bone. Differentiating strains in the gastroc and soleus is particularly important for an accurate prognosis, appropriate treatment, and successful prevention of recurrent injury.
Gastroc Strain - the gastroc kicks in at terminal time points during plantar flexion and ramps up as we do things more intensely. It is a powerhouse of a muscle! Gastroc strains have a high speed and intensity component, usually a combined knee extension and ankle dorsiflexion mechanism. The gastrocnemius is considered at high risk for strains because it crosses two joints (the knee and ankle) and has a high density of type two fast twitch muscle fibers.
Soleus Strain - the soleus is the workhorse of the lower leg and is critical in distance running. Half of soleus strains occur with no clear event. Symptoms include post-activity tightness or tightness during a run that gets worse throughout. Unlike the gastrocnemius the soleus is considered low risk for injury. It crosses only the ankle and is largely comprised of type one, slow twitch muscle fibers. Soleus strains also tend to be less drastic and traumatic when compared to gastroc injuries.
Rehabilitation
When it comes to rehabbing these injuries, your timeframe will depend on the grade of the injury or muscle tear. Research shows that injuries that occur more acutely have a significantly longer time to return to play, around 24 days average. Over the first couple of days to a week, stretching and lengthening of the muscle should be limited. If muscle contraction is painful, walking or weight bearing should be limited. Patients may need to wear a boot or use crutches to limit active ankle plantar flexion until pain-free walking can be achieved. Heat and massage are also usually avoided during these early stages.
Return To Run
Before returning to run, walking should be pain-free, range of motion restored, and calf strength comparable to the unaffected leg. The calf needs to develop the endurance and load capacity to withstand the demands of running and jumping. Too many runners make the mistake of rushing back to get that first run in and the risk of re-injury is heightened. Over half of the reoccurrences of calf strains occur within he first two months following initial injury. Developing calf resiliency requires a comprehensive rehab program which starts simple and builds in complexity and sport specificity.
If your calf pain lingers or returns, it might be time to take a look at your biomechanics and anatomy. Are you loading one leg more than the other? Does your foot strike lead to excess force through your plantar flexors? Is your hip, knee and ankle mobility sufficient for gait? Is your tendon elasticity poor? With calf strains that suddenly appear out of nowhere, the low back and spine should always be cleared. If you’ve suffered from a recent calf strain or are dealing with chronic calf issues, consult your PT or other medical professional for rehab guidance.
References:
Dixon, J. B. (2009). Gastrocnemius vs. soleus strain: how to differentiate and deal with calf muscle injuries. Current reviews in musculoskeletal medicine, 2(2), 74-77.
Green B, Pizzari T. Calf muscle strain injuries in sport: a systematic review of risk factors for injury. Br J Sports Med. 2017 Aug;51(16):1189-1194. doi: 10.1136/bjsports-2016-097177. Epub 2017 Mar 4. PMID: 28259848.
Orchard, J. W., Intrinsic and Extrinsic Risk Factors for Muscle Strains in Australian Football. The American Journal of Sports Medicine 2001,29 (3), 300-303.
Van Middelkoop M, Kolkman J, van Ochten J, Bierma-Zeinstra S, Koes BW (2008) Risk factors for lower extremity injuries among male marathon runners. Scand J Med Sci Sports 18: 691–697. doi: 10. 1111/j.1600-0838.2007.00768.x PMID: 182667
