The calf muscles are essential for our locomotion, enabling us to walk, run and jump.
They are the powerful muscles at the back of our lower legs and have the function of ankle plantar-flexion or pushing the front of the foot down, calf- or heel-raises, and push-off in locomotion.
The two main calf muscles are the gastrocnemius, the more superficial, with two heads attaching just above the knee and therefore having the function of bending the knee as well, and soleus, which is deeper, originating below the knee, attaching and running close to the bones down to the heel. Both join to form a common tendon, the achilles, inserting into the heel bone and connecting to the fascia under the foot.
There are subsidiary muscles that also plantar-flex the foot on either side of the ankle joint, (a total of 7 muscles passing behind the ankle joint), important for ankle stability, but the calf muscles comprise over 70% of the muscle mass and are responsible for 93% of the work in going up on the toes.
Good calf strength is important to avoid injury to the calf and foot, as well as affecting further up the lower limb chain to the hip, low back and beyond. Flexibility is also important in this area, although overstretching is not always helpful and may irritate some conditions.
Common injuries include muscle tears, achilles tendon ruptures, tears, acute tendinitis or tendon inflammation, or tendinosis which is a more chronic condition involving tendon degeneration without significant inflammation. Also, plantar heel pain and tibial stress syndrome are related to calf strength and flexibility.
Calf muscle weakness is surprisingly common. Many people are unaware that they have any weakness since they can walk about ok, but, when asked to do some single leg heel-raises are surprised at how few they can manage! It’s amazing how people can get about by throwing their weight from foot to foot without actually using their calves to push off!
The calf-raise test is a useful tool, but it’s worth noting that variations in the testing can provide different results. Testing on a flat floor is usually enough, facing a wall and using fingers on the wall for balance and with straight or bent knee (or test both). Depending on specific sports requirements, testing on an incline ( heel down) or full range with toes on the edge of a step may be useful, but not always necessary. Repeating the lift until failure or unable to continue gives a useful figure to record and use for reassessment later, but it’s also worth noting how high the heel lifts from the ground as this often lessens over time. The cadence,or speed, can also affect the test and performing it with a metronome 1 second up and 1 down is considered a good test unless faster or slower for specific sporting reasons.
Calf raise test outcomes have been associated with functional performance in several populations including 10m sprint performances in rugby players, walking speed & ankle power following surgical repair after achilles tendon rupture, locomotor capacity in children, functional fitness in older adults and functional capacity in people with peripheral arterial disease.
The median value for number of calf-raises is 25. Obviously this will vary a lot depending on age, weight, sex and activity levels. So it’s worth testing yourself. There’s a Calf Raise app which takes these factors into account which you may find helpful if interested.
Of course if you can’t manage single leg calf-raises, start with 2 feet, and if you can’t manage this there are other ways to get started such as resistance bands and resistance machines such as Pilates Reformers.
If you struggle with calf, achilles or foot pain seek advice from a physiotherapist or podiatrist.
So, get testing and strengthening! You may be surprised at how it improves your balance, walking, running, or other sporting performance!
Pip Deave
