Abstract:Exercises to improve joint proprioception and coordination of the functionally unstable ankle are advocated throughout the literature, yet there is little evidence that these exercises have any effect on proprioception and balance. The purpose of this study was to determine the effects of a 6-week coordination and balance training program on proprioception of subjects with functional ankle instability. Forty-five subjects (age = 22.53 ± 3.95 years, height = 172.04 ± 10.0 cm, weight = 71.72 ± 15.7 kg) were randomly placed into a control (Group 1), sham (Group 2), or experimental (Group 3) group. The experimental group trained 3 days per week, 10 minutes each day, performing various balance and proprioception exercises. Postural sway and active and passive joint position sense were assessed. Analysis of variance for postural sway modified equilibrium score for anterior and posterior sway, as well as medial and lateral sway revealed significant four-way interactions. Tukey post hoc analyses revealed that Group 3 performed significantly better (p < .05) than Group 1 and Group 2 on the posttests. There were no significant differences for joint position sense or postural sway index. Results suggest that balance and coordination training can improve some measures of postural sway. It is still unclear if joint position sense can be improved in the functionally unstable ankle. Article:Inversion ankle sprains are among the most common injuries in sports (22,39,70). Often, recurrent injury ensues, and functional instability (1517) becomes evident in as many as 33 (3) to 42% (18) of the patients suffering from an acute ankle injury. Contributing factors to functional ankle instability are decreased range of motion (4), decreased strength of ankle evertors (3,60,66), and a decrease in joint proprioception (8,18,21,25,43,61,66,67). Some authors reported symptoms of functional instability in the absence of mechanical instability (14,16,66).The ability to detect motion in the foot and make postural adjustments in response to these detected motions is crucial in the prevention of ankle injury. Similarly, the ability of an individual to sense the position of the foot prior to heel strike is of the utmost importance. Studies have shown that functional ankle instability results in a decreased ability to maintain balance (16,69) and a decrease in joint position sense (25).Freeman et al (18) proposed that ankle injury may cause disruption of joint afferents located in the supporting ligaments and capsule, leading to an impairment of the postural control system. Using a modified Rom-berg's test, they found a decrease in the ability to maintain static balance on the injured limb when compared to the uninjured limb of patients with unilateral ankle injury. From their finding of decreased postural control, they proposed a partial deafferentation of joint mechanoreceptors in the functionally unstable ankle, which contributed to symptoms of functional instability (18).

Changes in sex hormones mediate changes in knee laxity across the menstrual cycle. However, the strength of this relationship, the relative contribution of each hormone, and the associated time delay are highly variable between women. This individual variability is consistent with the variability in menstrual cycle characteristics among women.

Triple-hop distance is a useful clinical test to predict an athlete's lower extremity strength and power. Although THD was not a predictor of static balance, further research is needed to examine its relationship with more dynamic balance tests.

Females in this study appear to adopt a single leg landing style using less hip and knee flexion, absorbing less total lower body energy with more relative energy at the ankle resulting in a landing style that can be described as stiff. This may potentially cause increased demands on non-contractile components of the lower extremity. Preventative training programs designed to prevent knee injury may benefit from the biomechanical description of sex-specific landing methods demonstrated by females in this study by focusing on the promotion of more reliance on using the contractile components to absorb impact energy during landings.

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