Trend Symmetry of Dominant Limb During Prolonged Load Carriage
Dr. Tyler N. Brown
Musculoskeletal injuries are a common, costly military problem that may result from asymmetrical lower limb biomechanics during routine training exercises, such as prolonged walking with body borne load. But, it is currently unknown if military body borne load or duration of walking increase asymmetry of lower limb biomechanics. Fifteen (10 male, 5 female) participants had trend symmetry of the dominant limb quantified while walking at 3.0 m/s for 60 minutes with three body borne loads (0, 15, and 30 kg). Specifically, trend symmetry, including raw symmetry, phase shift, range amplitude, and range offset, were calculated for hip, knee, ankle motions and submitted to a linear model to test the main and interaction effects of time (0, 30, 60 minutes) and load (0, 15, 30 kg). Time, but not load impacted raw symmetry. Specifically, duration of walking had a significant effect on raw symmetry of hip adduction (p=0.035) and ankle internal rotation (p<0.001) motion. Neither load, nor time produced a phase offset in hip, knee, or ankle motion (p>0.05). Load impacted the range offset of ankle inversion motion (p=0.021), but no hip or knee motion (p>0.05). Both load and time impacted range amplitude. Specifically, load had a significant effect on range amplitude of knee (p=0.049) and ankle flexion (p=0.030) motions, while duration of walking had a significant effect on range amplitude of hip internal rotation motion (p=0.001). Body borne load and duration of walking may elevate injury risk by increasing asymmetry and altering lower limb motions during routine military training exercises.
Christensen, Fred W.; Drew, Micah; Krammer, Samantha; and Brown, Tyler N., "Trend Symmetry of Dominant Limb During Prolonged Load Carriage" (2020). 2020 Undergraduate Research Showcase. 26.