Afferent activity from the knee joint capsule resulted in an inhibitory effect on the vastus medialis and a facilitatory effect on the soleus. Facilitation of the soleus in cooperation with other lower extremity musculature could be a mechanism for compensation of the inhibited quadriceps to maintain lower kinetic chain function.

Background: Arthrogenic muscle inhibition (AMI) is a continuing reflex reaction of the musculature surrounding a joint after distension or damage to the structures of that joint. This phenomenon has been well documented after knee joint injury and has been generalised to occur at other joints of the human body, yet minimal research has been conducted in this regard. The response of the muscles crossing the ankle/foot complex after ankle injury and effusion is not well understood. AMI may occur after an ankle sprain contributing to residual dysfunction. Objective: To determine if AMI is present in the soleus, peroneus longus, and tibialis anterior musculature after a simulated ankle joint effusion. Methods: Eight neurologically sound volunteers (mean (SD) age 23 (4) years, height 171 (6) cm, mass 73 (10) kg) participated. Maximum H-reflex and maximum M-wave measurements were collected using surface electromyography after delivery of a percutaneous stimulus to the sciatic nerve before its bifurcation into the common peroneal and posterior tibial nerves. Results: The H-reflex and M-wave measurements in all muscles increased (p(0.05) after the simulated ankle joint effusion. Conclusions: Simulated ankle joint effusion results in facilitation of the soleus, peroneus longus, and tibialis anterior motoneurone pools. This may occur to stabilise the foot/ankle complex in order to maintain posture and/or locomotion.

The purpose of this study was to evaluate the effects of ankle bracing on rearfoot angular displacement and angular velocity during a sudden inversion movement. A 1 x 3 factorial design was used. The single independent variable was ankle brace condition with three levels: semi-rigid, lace-up and control. The two dependent variables were rearfoot average angular displacement and average angular velocity. Twenty-four healthy volunteers participated in this study. A motion analysis system was used to capture, model and calculate two-dimensional rearfoot motion while the subjects' ankle/foot complex was inverted to 35 degrees on a platform device. All subjects performed five trials of each ankle brace condition, and the average of these trials was used for statistical analysis. The semi-rigid brace significantly reduced rearfoot angular displacement and angular velocity compared with the lace-up (P<0.05) and control conditions (P<0.05). Additionally, the lace-up style brace demonstrated significantly less rearfoot angular displacement and angular velocity compared with the control condition (P<0.05). These results demonstrate that a semi-rigid ankle brace is more superior then a lace-up style brace in limiting rearfoot angular displacement and angular velocity. Moreover, the lace-up style brace offers significant restriction of these measures compared with no support.

Background: Braces are often used before returning to activity following ankle sprains and also prophylactically in sports considered the high risk for ankle sprains. The purpose of this study was to compare range of motion (ROM) limitations, functional performance, and satisfaction of rigid double upright and lace-up braces. Subjects: In total, 30 healthy adults >18 years of age (Mean, 22.6 6 2.7 years) without lower extremity injury and involved in regular physical activity participated in this study. Materials/Methods: Ankle ROM assessment and lower extremity performance testing (fig-ure-of-8 hop, side hop, 6-m single-limb crossover, and square hop) was administered under the following 3 conditions: unbraced, rigid braces, and lace-up braces. A questionnaire was completed following the test protocol on brace characteristics and satisfaction. Repeated-measures ANOVA was used to determine the main effects on outcome variables of ROM, hop performance, and satisfaction. Tukey LSD post hoc comparisons were conducted on significant main or interaction effects (P < .05) to determine differences between group by condition means. Results: In total, 30 participants completed the study. The lace-up brace limited plantarflex-ion and inversion ROM more than the rigid brace. When compared to the unbraced condition , both braced conditions resulted in better performance times, although not statistically significant. Higher satisfaction was reported with the lace-up brace on appearance, fit, prevention , and overall satisfaction. Conclusions and Clinical Relevance: The ankle braces primarily limited ankle plantarflex-ion and inversion ROM, which are motions related to common reported mechanisms of ankle sprains. The braces did not negatively affect hop performance, and user satisfaction indicated a slight preference for the lace-up brace. Original Research OPEN ACCESS Key Points: The ankle braces used in the current study did not negatively affect functional performance of the participants. Both braces controlled ankle range of motion, but the lace-up brace had a greater effect on limiting plantarflexion and inversion. Participants in this study expressed a slight preference for the lace-up braces.