Isometrics exercises for Achilles tendinopathy: the why, when & how
Updated: Jul 15
Isometric exercises have become a popular choice for treating tendinopathy since Rio’s 2015 paper on patellar tendinopathy (jumper's knee). So when & how can you perform these exercises for Achilles tendinopathy?
Isometric exercises are contractions of a particular muscle or group of muscles, during which the muscle doesn't noticeably change length & the affected joint doesn't move.
Should you use isometrics for your tendinopathy?
If these are to be an effective exercise for you, we like to see a reduction in at least 2 points on a scale out of 10 for a particular task (i.e hopping). So for example if you hop & experience a pain of 7/10 in your Achilles tendon, then perform some isometrics, re-try the hopping & if you then only feel a pain less than 5/10, it would be worthwhile adding these into your routine. By no means are these effective for EVERYONE with Achilles issues, we have previously written about Seth O'Neil's 2018 study & Clifford's 2020 systematic review, which found variable responses among those with tendinopathy (some experienced relief, others got worse).
What are the different isometric options for Achilles tendinopathy?
We like to use one (or a combination) of the following 4 exercises:
1. Standing single-leg calf raise with weight:
PROS: Easy to perform, with your body weight already going through that leg you generally don't need to add too much weight (20-30kg will often suffice & this can be held or put in a backpack).
CONS: doesn't work the lower calf muscle (soleus) as well as other options
2. Seated calf raise:
Performed with either barbell in a rack, using a Smith machine, seated calf raise machine or using a leg extension machine.
PROS- better isolate the soleus muscle.
CONS- reliance on equipment (barbell & weights, machine weights), needs to be a heavy weight (most people will need in excess of 70-80kg) and this can be uncomfortable with the weight resting on the knee (using pads as seen in this video can help).
3. Standing bent knee calf raise with weight:
The knee MUST be bent more than 60 degrees to isolate the soleus:
PROS- again easy to perform at home with only needing an extra 20-30kg, better isolates the soleus versus the straight leg version
CONS- holding the bent knee position can be quite taxing on the quads, so you may fatigue this before the calves!
4. Soleus table isometric:
Position yourself under a solid table. You will need to stack some things under your foot to get it to the right height. The correct position to push from here is having the knee over the toes, with the foot being just above parallel. Use a cushion between your knee & table for comfort. Then push up into the table hard!
PROS: doesn't require any fancy equipment, isolates the soleus muscle,
CONS: similar to the seated calf raise it can be a bit uncomfortable on the knee so use padding here, you need a heavy table to push up into otherwise the table will lift up off the ground!
How much weight? How long to hold?
It's important that with these isometrics that you make them challenging, so usually 70% of a 1 RM is ideal (we use testing on our AxIT force plates to help guide this weight).
Hold each position for 45 secs. Rest 60-120 secs, & perform 5 sets. Isometrics can be repeated twice daily during the acute, painful stage of tendinopathy.
It is important that you don't shake when performing these isometrics as this can actually irritate the tendon. If you find yourself shaking then reduce the resistance to the point where you can hold a nice steady contraction for a prolonged period of time.
For those needing help with their Achilles tendinopathy, please don’t hesitate to contact us at www.healthhp.com.au.
Clifford, C., et al. (2020). "Effectiveness of isometric exercise in the management of tendinopathy: a systematic review and meta-analysis of randomised trials." BMJ Open Sport & Exercise Medicine 6(1): e000760.
O'Neill, S., et al. (2018). "Acute sensory and motor response to 45-s heavy isometric holds for the plantar flexors in patients with Achilles tendinopathy." Knee Surg Sports Traumatol Arthrosc.
Rio, E., et al. (2015). "Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy." Br J Sports Med.