ABSTRACT
Persistent muscle weakness, tendon elongation, and incomplete return to preinjury level are frequent sequelae after acute Achilles tendon rupture, and evidence-based knowledge of how to best rehabilitate the injury is largely absent in the literature. The objective of this review is to illuminate and discuss to what extent an Achilles tendon rupture affects muscle, tendon, and function when assessed with the Achilles tendon total rupture score (ATRS), muscle strength, muscle cross-sectional area, tendon length, and the heel-rise test. The patient-reported outcome measures (PROM) data in the literature suggest that the recovery takes longer than 6 months (ATRS, 70 out of 100), that one-year postinjury, the ATRS only reaches 82, and that this does not appear to noticeably improve thereafter. Loss of muscle mass, strength, and function can in some cases be permanent. Over the first 6 months postinjury, the tendon undergoes elongation, which appears to be negatively correlated to heel-rise function. More recently, there has been some interest in how muscle length and excursion is related to the reduced function. The available literature indicates that further research is highly warranted and that efforts to restore normal tendon length may improve the likelihood of returning to preinjury level after an Achilles tendon rupture.
ABSTRACT
BACKGROUND: In the treatment of an Achilles tendon rupture the patients are commonly equipped with an orthopaedic walker boot with wedges. To what extent this influences the tensile force placed on the Achilles tendon is unclear. PURPOSE: To assess the forefoot force and describe changes in muscle activity of the medial gastrocnemius, soleus and tibialis anterior when using one or three wedges during ambulation in a weightbearing orthopaedic walker boot. METHODS: The force on the forefoot was measured with a force sensor insole and muscle activity of the medial gastrocnemius, soleus and tibialis anterior were measured using surface electromyography in 10 healthy participants. Three different types of ambulation were performed (walking without crutches (unass.), walking with crutches (+crutch) and walking with crutches and verbal instructions to place body weight on heel (heel+crutch) with one and three heel wedges respectively. FINDINGS: The total peak force displayed an interaction where forefoot force decreased when wearing three wedges only for the +crutch ambulation type (80N, p=0.001) although there was a trend to decrease with three wedges also for the heel+crutch ambulation type (48N, p=0.05). The relative peak force on the forefoot showed a main effect with a significant decrease when using three wedges compared to one wedge across all three ambulation types (19.1%, p=0.009). INTERPRETATION: The force on the forefoot and hereby the Achilles tendon significantly decreased when using three wedges compared to one wedge. These findings have important implications for the rehabilitation post Achilles tendon rupture.