Mid-portion Achilles tendinopathy (AT) is a common overuse musculoskeletal condition causing pain and disability. There are two commonly used conservative interventions. Calf muscle eccentric exercise has been found to be effective in decreasing pain and improving function in people with AT. Heel lifts reduce ankle joint dorsiflexion and Achilles tendon strain, however the efficacy of this intervention for AT has not been determined. The aim of this trial, therefore, was to compare the efficacy of heel lifts against calf muscle eccentric exercise for reducing pain and improving function in AT.
One hundred participants aged between 22 to 66 years (45.9 ± 9.4) with AT were randomised to receive either Clearly Adjustable® 12 mm heel lifts (n = 50) or a calf muscle eccentric exercise program (n = 50). Outcome measures were obtained at baseline, 2, 6 and 12 weeks, the primary end-point. The primary outcome measure was the Victorian Institute of Sports Assessment-Achilles questionnaire (VISA-A). Secondary outcome measures included thickness and integrity of the Achilles tendon, global impression of change (pain and function), severity of pain (100 mm visual analogue scale) and calf muscle function (calf rise test). Data was analysed using the intention to treat principle. VISA-A and global impression of change in symptoms at 12 weeks are presented below.
Both groups improved in pain and function. After 12 weeks, there was no significant difference in VISA-A scores between the two groups (adjusted mean difference at week 12 = 4.5 points, 95% CI -3.0 to 12.1, p=0.232). However, statistically significant differences between groups were found for patient global impression of change in symptoms in favour of heel lifts at 12 weeks (pain: RR 1.41, CI 1.02 to 1.95; function RR 1.55, CI 1.04 to 2.31).
Discussion and clinical relevance
There is no difference in efficacy between heel lifts and calf muscle eccentric exercise for AT. Heel lifts can be considered a simpler and alternative intervention to calf muscle eccentric exercise for AT.