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Gait and movement asymmetries are important variables for assessing locomotor mechanics in humans and other animals and as a predictor of risk of injury and success of clinical interventions. The four indices used most often to assess symmetry are not well designed for different variable types and perform poorly when presented with cases of high asymmetry or when variables are of low magnitude and are easily influenced by small variation in the signal. The purpose of the present study was to test the performance of these indices on previously unpublished data on ACL-R patients and to propose a new index to resolve some of these limitations. The performance of four currently used indices and a new index-the Normalized Symmetry Index (NSI), which is scaled to the range of variables being tested across multiple trials-were compared using force and angular data on participants who had undergone anterior cruciate ligament reconstruction and healthy controls. The NSI performed well compared to all other indices with all variables and had the additional benefit of returning values that range from 0% (full symmetry) to ±100% (full asymmetry). Therefore, the NSI can serve as a universal index for assessing asymmetry in humans, nonhuman animal models, and in a clinical context for assessing risk for injury and clinical outcomes.

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Background: Athletes who return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) often have reduced physical performance and a high reinjury rate. Additionally, it is currently unclear how physical performance measures can change during the RTS transition and with the use of a functional knee brace. Purpose/Hypothesis: The purpose of this study was to examine the effects of time since surgery (at RTS and 3 months after RTS) and of wearing a brace on physical performance in patients who have undergone ACLR. We hypothesized that physical performance measures would improve with time and would not be affected by brace condition. Study Design: Controlled laboratory study. Methods: A total of 28 patients who underwent ACLR (9 males, 19 females) completed physical performance testing both after being released for RTS and 3 months later. Physical performance tests included the modified agility t test (MAT) and vertical jump height, which were completed with and without a knee brace. A repeated-measures analysis of variance determined the effect of time and bracing on performance measures. Results: The impact of the knee brace was different at the 2 time points for the MAT side shuffle ( P = .047). Wearing a functional knee brace did not affect any other physical performance measure. MAT times improved for total time ( P < .001) and backpedal ( P < .001), and vertical jump height increased ( P = .002) in the 3 months after RTS. Conclusion: The present study showed that physical performance measures of agility and vertical jump height improved in the first 3 months after RTS. This study also showed that wearing a knee brace did not hinder physical performance. Clinical Relevance: Wearing a functional knee brace does not affect physical performance, and therefore a brace could be worn during the RTS transition without concern. Additionally, physical performance measures may still improve 3 months past traditional RTS, therefore justifying delayed RTS.

It is estimated that approximately 40% of the population suffers from abnormal foot posture, specifically high arched or low arched feet. While the evaluation of foot posture can involve many aspects, it commonly requires the measurement of basic dimensions of the foot. Clinicians and researchers often rely on the use of specialized devices or 3D scanners to evaluate specific aspects of a patient's foot posture. However, current technologies are extremely expensive, therefore highlighting the need for a cost-effective device to be used in rural and clinical settings. Therefore, the purpose of this study was to develop an inexpensive system to measure total foot length, truncated length, dorsum height, navicular height, and foot width. Bland-Altman plots showed significant differences between this measurement system and a 3D scanner for total foot length, truncated length, and navicular height (p&lt;0.001) and significant differences when assessing the repeatability of dorsum height (p=0.022). However, interclass correlation coefficients revealed that this system had excellent validity when compared to a 3D scanner (ICC = 0.908-0.994), and good to excellent repeatability when compared between days (ICC = 0.867-0.996). These results demonstrate that it is possible to design an inexpensive, valid, and repeatable system that can be used in clinical, research, and rural settings to successfully evaluate basic dimensions of the foot that can be used for the determination of foot type.