The calf complex consists of two muscles: The gastrocnemius and soleus. Both muscles share the common insertion (combining to form the Achilles tendon) at the posterior aspect of the calcaneus. They perform plantar flexion of the foot during toe off and provide eccentric control during dorsiflexion in mid-stance during running.
We know from Dr. Rich Willy (2019) that the calf complex is extremely important, attributing up to 50-60% of force production when running.
EMG studies have shown the soleus in particular is the powerhouse for runners, finding it produces up to 6.5-8 times body weight of force during running. Studies have also found soleus force production remains largely consistent throughout low, moderate and high running speeds. This is unlike the hamstring muscle which is required more as running speed increases (Dorn et al., 2012).
This should highlight why building the strength capacity of the calf complex to meet the demands of running is essential for all recreational or elite runners when completing rehabilitation.
Mastering your calf strain rehabilitation program:
Before I discuss individual exercises for the calf complex, it is important to acknowledge muscle strains are mostly due to extrinsic factors (training loads). It is estimated 60% of all running related injuries could be attributed to training errors – load vs capacity mismatch – increases in frequency of sessions, intensity, volume or elevation i.e. running too far, too fast and too quick (Hein et al., 2014 & Hreljac, 2005).
A structured return to running program should be a part of a detailed rehabilitation plan to initially adequately reduce and gradually increase running loads as calf capacity increases.
How to build calf complex capacity:
At the 2021 Australian Physiotherapy Association Sports Symposium finding the edge – optimising athletic performance, 6 components were outlined to consider when completing a detailed calf rehabilitation program, these include: vertical strength, horizontal strength, stiffness, intrinsics, endurance and technical.
- Progressively loading calf raises:
- With the knee straight in standing (targeting the gastrocnemius) and with the knee bent in standing or sitting (targeting the soleus).
- Goals for vertical strength:
- Single leg
- Add weight, start low, progressively increase, aim up to 50-100% of body weight (this can be done with a smith machine/barbell, seated calf raise machine at the gym or giving the kids a piggie back/ sitting on your knee if in lockdown).
- Horizontal strength is often neglected, however we don’t run on the spot, we run forwards.
- Examples of horizontal strengthening exercises:
- Walking lunges
- Sled push
- Forward hops
- Hill/stair repeats (start walking, then progress to running when ready, following your return to running program).
- Think of your calf complex as a spring, a stiffer spring will produce more recoil.
- Heavy weighted single leg isometrics (set and hold calf raises).
- Walking on toes + add weight (via dumbbells, barbells or wearing a backpack/carry shopping bags if in lockdown).
- Walking on toes up a hill or stairs.
Plyometrics have also been showed to improve tendon stiffness, running performance and economy (Foure et al., 2010 & Garcia-Pinillos et al., 2020).
- Plyometric exercises include:
- Progress to single leg hopping.
- Arguably I believe this is probably the least important component of the group and would constitute as the 1%’ers.
- There is limited, low level of evidence finding increased medial arch drop and pronation when the intrinsic foot muscles are fatigued (Cheung et al., 2015 & Headlee et al., 2008).
- Furthermore, it may be inferred that strengthening the intrinsic foot muscles could improve medial arch stiffness, which was found to be associated with improved running performance (Garcia-Pinillos et al., 2020).
- We will discuss specific intrinsic foot muscle exercises in an upcoming blog.
- Building endurance of your calf complex could include:
- Progressively increasing walking duration (progress to running when ready, following your return to running program).
- Performing lighter weight with more repetitions until fatigue.
- Increase skipping duration.
Technical (Sport specific technique and leg speed drills – A, B skips)
- Introducing sport specific technique and leg speed drills such as:
- A skips and B skips.
- High knees and heel to bum flicks.
- Fast feet drills.
Note: no components are prioritising stretching or flexibility.
Considering all the aspect above to optimise calf capacity and manage extrinsic training loads will help decrease return to running time, reduce the risk of re-injury and return the runner to optimal performance.
Cheung, R. T. H., Sze, L. K. Y., Mok, N. W., & Ng, G. Y. F. (2016). Intrinsic foot muscle volume in experienced runners with and without chronic plantar fasciitis. Journal of Science and Medicine in Sport, 19(9), 713-715. https://doi.org/10.1016/j.jsams.2015.11.004
Dorn, T. W., Schache, A. G., & Pandy, M. G. (2012). Muscular strategy shift in human running: Dependence of running speed on hip and ankle muscle performance (vol 215, pg 1944, 2012). Journal of Experimental Biology, 215(13), 2347-2347. https://doi.org/10.1242/jeb.075051
Fouré, A., Nordez, A., & Cornu, C. (2010). Plyometric training effects on achilles tendon stiffness and dissipative properties. Journal of Applied Physiology, 109(3), 849-854. https://doi.org/10.1152/japplphysiol.01150.2009
García-Pinillos, F., Lago-Fuentes, C., Latorre-Román, P. A., Pantoja-Vallejo, A., & Ramirez-Campillo, R. (2020). Jump-rope training: Improved 3-km time-trial performance in endurance runners via enhanced lower-limb reactivity and foot-arch stiffness. International Journal of Sports Physiology and Performance, 15(7), 927-933. https://doi.org/10.1123/ijspp.2019-0529
Headlee, D. L., Leonard, J. L., Hart, J. M., Ingersoll, C. D., & Hertel, J. (2008). Fatigue of the plantar intrinsic foot muscles increases navicular drop. Journal of Electromyography and Kinesiology, 18(3), 420-425. https://doi.org/10.1016/j.jelekin.2006.11.004
Hein, T., Janssen, P., Wagner-Fritz, U., Haupt, G., Grau, S. (2014). Prospective analysis of intrinsic and extrinsic risk factors on the development of achilles tendon pain in runners. Scandinavian Journal of Medicine & Science in Sports, 24(3), 201-212. https://doi.org/10.1111/sms.12137
Hreljac, A. (2005). Etiology, Prevention, and Early Intervention of Overuse Injuries in Runners: a Biomechanical Perspective. Physical Medicine and Rehabilitation Clinics of North America, 16, 651-667. doi:10.1016/j.pmr.2005.02.002
Willy, R., Parquette, M. (2019). The Physiology and Biomechanics of the Master Runner. Sports Medicine and Arthroscopy Review, 27(1), 15-21. doi: 10.1097/JSA.0000000000000212