Context: Plyometric exercise has been recommended to prevent lower limb injury, but its feasibility in and effects on those with functional ankle instability (FAI) are unclear. Objective: To investigate the effect of integrated plyometric and balance training in participants with FAI during a single-legged drop landing and single-legged standing position. Design: Randomized controlled clinical trial. Setting: University motion-analysis laboratory. Patients or Other Participants: Thirty athletes with FAI were divided into 3 groups: plyometric group (8 men, 2 women, age = 23.20 ± 2.82 years; 10 unstable ankles), plyometric-balance (integrated)–training group (8 men, 2 women, age = 23.80 ± 4.13 years; 10 unstable ankles), and control group (7 men, 3 women, age = 23.50 ± 3.00 years; 10 unstable ankles). Intervention(s): A 6-week plyometric-training program versus a 6-week integrated-training program. Main Outcome Measure(s): Postural sway during single-legged standing with eyes open and closed was measured before and after training. Kinematic data were recorded during medial and lateral single-legged drop landings after a 5-second single-legged stance. Results: Reduced postural sway in the medial-lateral direction and reduced sway area occurred in the plyometric- and integrated-training groups. Generally, the plyometric training and integrated training increased the maximum angles at the hip and knee in the sagittal plane, reduced the maximum angles at the hip and ankle in the frontal and transverse planes in the lateral drop landing, and reduced the time to stabilization for knee flexion in the medial drop landing. Conclusions: After 6 weeks of plyometric training or integrated training, individuals with FAI used a softer landing strategy during drop landings and decreased their postural sway during the single-legged stance. Plyometric training improved static and dynamic postural control and should be incorporated into rehabilitation programs for those with FAI.

To compare the differences in sit-to-stand and stand-to-sit movements of older nonfalling males and older male fallers (also referred to herein as fallers) to contribute to the development of posture transfer–assisting devices or interventional therapies to prevent falls. Controlled study. University research laboratory. Ten older men (mean age, 75.9±5.4 years) who had fallen or been unstable at least once in the past year and 10 nonfalling older men (mean age, 70.0±5.0 years) participated in this study. Not applicable. Movement duration; sagittal trunk, hip, knee, and ankle joint range of motion (ROM); anteroposterior and mediolateral (ML) center of mass (COM) total trajectory. During the sit-to-stand transition, fallers exhibited greater trunk joint ROM in the flexion and extension phase and smaller hip joint ROM in the extension phase as well as greater ML COM total trajectory. During stand-to-sit, older fallers exhibited greater trunk joint ROM in the flexion phase and smaller hip and knee joint ROM in the flexion phase as well as greater ML COM total trajectory. Older fallers took more time to perform the stand-to-sit and had greater ML COM total trajectory during the movement; additionally, they exhibited different proportional distributions of ROM for each joint compared with nonfaller. Older fallers had more difficulty performing stand-to-sit than sit-to-stand; they exhibited more body sway in COM motion and, in particular, were unable to control ML motion y. Older fallers were more likely to adopt trunk, hip, and knee joint flexion strategies to maintain balance during sit-to-stand and stand-to-sit than nonfaller participants were.