Article Title



L. Matz1, Y. Chun2, C. Johannsen3, L. Krumpl1, N. Martonick1, J. P. Bailey1

1University of Idaho

2 Sonoma State University

3University of Washington

Assistive devices have aimed to correct form, reduce injury, and increase performance. PURPOSE: To investigate the effects of a passive elastic corrective device on movement mechanics. METHODS: Participants (n=12, Age =24.7yrs [±4.5], mass=87.9kg [±18.6]. Lifting experience: 0yrs n=2; 1-3yrs n=2; 4-5yrs n=3; 5+yrs n=5) performed three back squat (BS) trials at each load condition (body weight [BW], 50% of 5 rep max [5RM], 5RM) per device condition (with or without). 12 surface electromyography sensors (sEMG) were attached bilaterally (Rectus Femoris, Biceps Femoris, Gluteus Maximus, and Medius, Adductor Longus [AL], Erector Spinae [ES]). Foot position and footwear were self-selected and matched between conditions. Device condition was counterbalanced with load condition being from BW to 5RM. The squat was divided into 4 phases, initial and final of eccentric and concentric phases. Signals were demeaned, bandpass filtered, and full wave rectified. RMS values were averaged for each squat phase. Differences were assessed with 2*2 (limb*device condition) mixed model ANOVAs (a= 0.05). RESULTS: No interactions were found for AL and ES. AL significantly increased muscle activation across all load conditions and squat phases (Table 1; p<0.05); significantly greater muscle activation was found in the left leg during 100%5RM (Table 1; p<0.05). ES muscle activation with device significantly decreased (Table 1; p=0.036). No other significant differences were found across muscles. CONCLUSION: Increased AL muscle activation with device is in response to the device providing abduction tension. The lack of changes in many other muscles may be attributed to individual variability of movement patterns.

Table 1.docx (15 kB)
Table 1

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