The effect of unilateral arm swing motion on lower extremity running mechanics associated with injury risk.

Many field sports involve equipment that restricts one or both arms from moving while running. Arm swing during running has been examined from a biomechanical and physiologic perspective but not from an injury perspective. Moreover, only bilateral arm swing suppression has been studied with respect to running. The purpose of this study was to determine the influence of running with one arm restrained on lower extremity mechanics associated with running or sport-related injury. Fifteen healthy participants ran at a self-selected speed with typical arm swing, with one arm restrained and with both arms restrained. Lower extremity kinematics and spatiotemporal measures were analysed for all arm swing conditions. Running with one arm restrained resulted in increased frontal plane knee and hip angles, decreased foot strike angle, and decreased centre of mass vertical displacement compared to typical arm swing or bilateral arm swing restriction. Stride length was decreased and step frequency increased when running with one or both arms restrained. Unilateral arm swing restriction induces changes in lower extremity kinematics that are not similar to running with bilateral arm swing restriction or typical arm swing motion. Running with one arm restrained increases frontal plane mechanics associated with risk of knee injury.

Automated assessment of postural stability system.

The Balance Error Scoring System (BESS) is one of the most commonly used clinical tests to evaluate static postural stability deficits resulting from traumatic brain events and musculoskeletal injury. This test requires a trained operator to visually assess balance and give the subject a performance score based on the number of balance "errors" they committed. Despite being regularly used in several real-world situations, the BESS test is scored by clinician observation and is therefore (a) potentially susceptible to biased and inaccurate test scores and (b) cannot be administered in the absence of a trained provider. The purpose of this research is to develop, calibrate and field test a computerized version of the BESS test using low-cost commodity motion tracking technology. This `Automated Assessment of Postural Stability' (AAPS) system will quantify balance control in field conditions. This research goal is to overcome the main limitations of both the commercially available motion capture systems and the standard BESS test. The AAPS system has been designed to be operated by a minimally trained user and it requires little set-up time with no sensor calibration necessary. These features make the proposed automated system a valuable balance assessment tool to be utilized in the field.