This study illustrates the validity and reliability of the KOOS in measuring the functional status and quality of life of athletes after ACL reconstruction. This study further validates the use of the KOOS in highly competitive athletes in research on knee injuries.

Prognostic study, case-control, Level III.

Lateral ankle sprains are one of the most common injuries among physically active individuals, especially those who participate in soccer, basketball, and volleyball.5 Furthermore, the recurrence rate has been estimated to be as high as 80%.11 The repeated ankle injury and giving-way feelings that occur in some individuals after the first sprain lead to a condition that has been defined as functional ankle instability (FAI).10 Neuromuscular deficits are believed to have a major contribution to the development of FAI. Poor postural control, which t StUdy deSiGN: Case-control study.t oBJeCtive: To compare the effect of dualtasking on postural and cognitive performance between subjects with functional ankle instability (FAI) and a matched control group without FAI.t BaCKGroUNd: Deficit and expertise in sensorimotor functions have been proposed as factors that can modify the interference between postural control and cognition. To the authors' knowledge, no study has investigated the posture-cognition interaction in individuals with recurrent ankle sprain, an orthopaedic condition with documented sensorimotor deficits.t MethodS: Single-limb postural stability was assessed in 15 recreational athletes with FAI and 15 matched healthy athletes without FAI. Each athlete stood on a Biodex Stability System at platform stabilities of 7 and 5, while they performed or did not perform a digits-backward cognitive task. Overall stability index (OSI), anteroposterior stability index (APSI), and mediolateral stability index (MLSI) were used as measures of postural performance. t reSUltS: At stability level 5, the individuals in the FAI group had poorer postural stability compared to those in the group without FAI (OSI, P.01; MLSI, P.01). A significant increase in OSI (P.01) and MLSI (P = .02) was also demonstrated by the individuals in the FAI group during dual-task performance compared to the single-task performance.t CoNClUSioN: Subjects with FAI demonstrated poorer postural stability when tested at level 5 on the Biodex Stability System, but not at level 7. Also, the results indicate that concurrent performance of a cognitive task decreased postural stability in the subjects with FAI, suggesting an increased dependency on attentional demands for maintenance of balance in that group. Such findings highlight the need for the assessment of postural control in patients with ankle sprain to include cognitive loading.

At the time of return to sports, the STG group had better performance in terms of quadriceps strength and the results of the triple-hop, crossover-hop, and jump-landing tests compared with the BPTB group. Compared with controls, soccer players who had undergone ACL reconstruction had less quadriceps and hamstrings strength and inferior hop performance and jump-landing strategy.

The purpose of this study was to investigate the effects of unilateral muscle fatigue induced on the hip flexors/extensors or the ankle plantar/dorsiflexors on unipedal postural stability under different visual conditions. Twenty-four healthy young women completed 2 testing sessions 1 week apart with a randomized order assigned according to the muscles tested. During each session, one set of muscle groups was fatigued using isokinetic contractions: ankle plantar/dorsi flexors or hip flexor/extensors. Postural stability was assessed during trials of unilateral stance on a force plate before and after the fatigue protocol. 10 s into the trial, subjects were asked to close their eyes. Mean velocity, the area of the 95% confidence ellipse, and standard deviation of velocity in anteroposterior and mediolateral directions of center of pressure displacements were calculated for two periods of 5 s, immediately before and 1 s after the eyes closure. The results of the repeated measures ANOVAs showed a significant fatigue-by-fatigue segment by visual condition interaction for the CoP parameters. When the vision was removed, the interaction between fatigue and fatigue segment was significant for the CoP parameters. In conclusion, fatigue in both proximal and distal musculature of the lower extremity yielded decreased postural stability during unipedal quiet standing in healthy young women. This effect was more accentuated when visual information was eliminated. Withdrawing vision following fatigue to the proximal musculature, led to a significantly greater impairment of postural stability compared to the fatigue of more distal muscles.