In 2012 a study conducted by Smith, et. al., at a university athletic training research laboratory has shed light on the effects of strength training on ankle rehabilitation, specifically in individuals with functional ankle instability (FAI). Despite the widespread use of strength training in rehabilitating ankle injuries, the study reveals that while such training significantly enhances ankle strength, it does not improve proprioception, or force sense, in affected individuals.

The randomized controlled clinical trial involved 40 participants, equally divided between men and women, all of whom suffered from FAI. The participants were randomly assigned to either a training group or a control group. The training group, comprising 20 individuals, engaged in a 6-week strength-training regimen focusing on the injured ankle, performed three times a week. The protocol combined the use of rubber exercise bands and the Multiaxial Ankle Exerciser, which are both well-established methods in clinical ankle rehabilitation. Over the six weeks, the resistance and number of sets in the exercises were progressively increased.

Measurements of strength and force sense were taken using a load cell, with inversion and eversion strength recorded to the nearest 0.01 Newton (N). Additionally, force-sense reproduction was assessed at two different loads: 20% and 30% of the participants’ maximal voluntary isometric contraction.

The results of the study were clear: the training group exhibited significant increases in both inversion and eversion strength compared to the control group. Specifically, inversion strength showed a marked improvement (F(1,38) = 11.59, P < 0.01, η(p)(2) = 0.23, power = 0.91), while eversion strength saw an even more substantial increase (F(1,38) = 57.68, P < .01, η(p)(2) = 0.60, power = 0.99). However, when it came to force sense, no significant improvements were observed in either group.

The findings suggest that while a structured strength-training program can effectively enhance muscle strength around the ankle in individuals with FAI, it does not translate to improvements in proprioception. This distinction is crucial for clinicians and trainers, highlighting the need for incorporating additional proprioceptive training exercises to fully address the rehabilitation needs of individuals with ankle instability.

This study underscores the complexity of ankle rehabilitation and the necessity of a multifaceted approach to effectively restore both strength and proprioceptive function in patients with FAI.

Reference: Smith, B. I., Docherty, C. L., Simon, J., Klossner, J., & Schrader, J. (2012). Ankle strength and force sense after a progressive, 6-week strength-training program in people with functional ankle instability. Journal of athletic training, 47(3), 282-288.