Why Is Calf Strength Important?

The calves play a significant role in daily life, as well as in many sporting endeavours including running where the Gastroc and Soleus complex are found to be the primary propulsors for forward movement (Hamner et al 2010) and research has shown that these muscles can also take from 6.5-8 x bodyweight in running movements (Dorn et al 2014).

As a result, injury to the gastrocnemius, soleus, Achilles tendon, and triceps surae muscle-tendon unit is common, with the calf raise test (CRT) often employed clinically for diagnosis and monitoring purposes (Hebert-Losier, Schneiders, Newsham-West, & Sullivan, 2009).

From the research we find that:

• Six months following ACL reconstruction, an average unilateral calf strength deficit of 8% was present, as measured by testing procedures dictating greater than 25 repetitions and a difference between sides of five or less on the CRT, likely to significantly affect loading absorption and propulsion during running (Schlumberger, 2002)
• For endurance athletes with suspected Achilles injury, a soleus-biased CRT should be considered due to the soleus’ high involvement in repetition-based exercise (Hebert-Losier et al., 2009)
• For racquet-sport athletes, a gastrocnemius-biased CRT should be conducted due to the gastrocnemius’ predisposition for explosive contraction (Hebert-Losier et al., 2009) 
• The CRT should be implemented with testing parameters applicable to the individual patient (Kolt, & Snyder-Mackler, 2007)
• Large statistically & clinically meaningful differences in plantar flexor strength & endurance between subjects with and without Achilles tendinopathy. (O’Neill 2018)
• "With symptomatic & asymptomatic limbs being weaker in those with AT, researchers & clinicians cannot use the non-symptomatic limb as a comparator when assessing strength & endurance, instead normative values need to be considered.” (O’Neill 2018)

How To Perform a Calf Raise Strength Test.

A Calf Raise Strength Test can be accomplished either by bodyweight or using a calf raise machine.

Importantly, differentiation between the gastrocnemius and soleus muscles should be considered for more accurate identification of contributing muscles, with the gastrocnemius playing a dominant role when in a straight knee position due to its biarticular nature, whilst in contrast, the soleus is favoured during varying degrees of knee flexion (Hebert-Losier, Newsham-West, Schneiders, & Sullivan, 2009).

To perform a Calf Raise Strength Test the subject is instructed to take up a position on a step or in a Calf Raise machine against a fixed resistance. On the assessor's cue the patient or client presses through their toes to full plantar flexion and then down into full dorsiflexion. This can also be performed to a metronome beat of 40-60 raises per minute for more standardization of procedure.

The amount of full repetitions is counted and compared from side to side to look for deficiencies or imbalances in strength with many pieces of research quoting 25+ successful repetitions as being a strength normal. (Hebert-Losier et al., 2009)

Are you using Single-Leg Calf Raises with your patients and clients?

Join the thousands of therapists and trainers worldwide who have stopped guessing and started measuring their patients and clients using objective strength testing and the MAT.

Sign up for our MAT Course today to learn how to use Single Leg Calf Raises alongside 50+ other objective assessments.

Click here to sign up for the MAT Course today.