Achilles Tendinitis (Tendinosis) Physical Therapy Protocol
1. Flexibility: Calf Stretching
To relieve the constant, excessive strain on the collagen fibers of the tendon and it’s attachment.
2. Strength: Eccentric Calf Strengthening
To allow the body to better absorb shock and control its own movement to protect and heal itself. Here is a summary of the protocol:
- Begin after short period of rest or boot use
- Gradual, 12 week strengthening program
- Patients should “work through” the pain
- 7 days/week, use a secure step
- Knee must be straight, heels over the edge
- Raise up onto toes using unaffected side to help
- Slowly lower to below level of step WITHOUT help from the other side (just to level with step if painful)
- 3 sets x 15 reps with 30 seconds rest between sets
Note to the physical therapist: This is better described as a tendinosis, which is a chronic metaplasia or mucoid degeneration of the tissue (swelling, disorganized tissue) and most likely due to overuse, poor mechanics and inadequate rest between workouts. This article from the International Journal of Therapeutic Massage & Bodywork is excellent and is a must-read.
3. Return to Sport
Further Detail and Rationale for Eccentric Musculotendinous Strengthening:
Curwin,33 and Curwin and Stanish34 in 1984, stressed the importance of eccentric training as a part of the rehabilitation of tendon injuries. They demonstrated the success of a simple 6‐week programme of progressive tendon load.34 Alfredson et al adapted this programme and scientifically evaluated an eccentric calf muscle training programme for painful mid‐portion Achilles tendinopathy.2,35
Alfredson’s model of eccentric training involves no concentric loading and emphasises the need for patients to complete the exercise protocol despite pain in the tendon. If patients experience no tendon pain doing this program, the load should be increased until the exercises provoke pain. Good short‐term and long‐term clinical results have been reported.35,36,37 This 12‐week programme is effective when the other conventional treatments (rest, NSAIDs, change of shoes, orthoses, physical therapy and ordinary training programmes) have failed and is successful in approximately 90% of those with mid‐tendon pain and pathology. Insertional Achilles tendon pain is not as responsive, and good clinical results are achieved in approximately 30% of tendons.38
A follow‐up study (mean 3.8 years later) of patients treated with eccentric training indicated the majority of the patients were satisfied and back to previous tendon‐loading activity level. Interestingly, the tendon thickness had decreased significantly, and ultrasonographically the tendon structure looked more normal.39The same 12‐week programme resulted in a decrease in tendon volume assessed with MRI, as well as a decrease in tendon signal intensity by 23%.40
Other exercise regimes that incorporate an eccentric component are also effective,41 but have not been as rigorously evaluated as the Alfredson programme. A concentric calf‐muscle training programme (calf raises) did not prove as effective as the eccentric (heel‐drop) training programme.42 In the eccentric group, 82% of patients were satisfied and back to previous activity level at the completion of treatment compared with those doing concentric exercise (36% satisfied patients).
Why does eccentric exercise reduce pain in tendinopathy?
Although there are several possible explanations for the effectiveness of eccentric exercise, none have been fully investigated. Eccentric exercise alters tendon pathology in both the short term and the long term. In the short term, a single bout of exercise increases tendon volume and signal intensity on MRI.43 A programme of eccentric exercise affects type I collagen production and, in the absence of ongoing insult, may increase the tendon volume over the longer term.44 As such, an eccentric exercise programme may increase tensile strength in the tendon over time. The effect of repetitive stretching, with a “lengthening” of the muscle–tendon unit, may also have an impact on capacity of the musculotendinous unit to effectively absorb load.
Another possible mechanism of action relates to mechanical insult of the pain‐producing nerves. A unique feature of Alfredson’s eccentric training programme is that the patient is encouraged to undertake painful heel‐drop exercises. As the nerve structures found in painful human tendons lie in close proximity to the tendon vessels, and as these vessels disappear with muscle contraction and stretch, the good clinical effects demonstrated with eccentric training could be due to alteration of the neovascularisation and accompanying nerves. The number of repetitions (180 repetitions/day) may damage the vessels and accompanying nerves as they traverse the soft tissue outside the tendon into the dense tendinosis tissue. The finding that patients satisfied with the result of the eccentric training regimen had no neovascularisation remaining, and all patients with a poor clinical result continued to have neovascularisation,39 is consistent with this hypothesis. However, that observation could also be the result of other upstream stimuli that influence both pain and neovascular obliteration, so we are not in a position to draw causal conclusions from an observational study.