Article Title



D. Schrader, R. Houser, S.O. Henry, J. Miller

Pacific University, Forest Grove, OR

Current research suggests stretching, and the associated increase in range of motion (ROM), decreases performance. However, those studies have usually stretched the muscle directly responsible for the performance task (agonist). Very few studies have isolated the antagonist musculature for the stretching intervention, while using performance of the agonist musculature as the dependent variable. PURPOSE: To determine the acute effects of increased antagonist ROM on agonist muscle force and energy expenditure. METHODS: Ten participants (6 male, 4 females; 170.26 + 3.2 cm stature; 77.86 + 9.44 kg mass) completed baseline assessment of hip abduction passive ROM (PROM, degrees), hip abduction active ROM (AROM, degrees), and peak hip abduction force (newtons). The experimental design required participants to complete two 5-min trials of standing hip abduction movements, one trial pre-stretching (baseline PROM) and one trial post-stretching (criterion >15% PROM). Each trial consisted of repetitively abducting one leg (30 per min) to 80% of original baseline AROM for 5 min. Peak force, PROM, AROM and gaseous exchange data were assessed. Using principles of indirect calorimetry, steady-state VO2and VCO2were used to calculate energy expenditure (kJ∙min-1). Paired two-tailed t-tests compared force and energy expenditure for non-stretched and stretched trials. RESULTS: The experimental design was predicated upon a participant having different ROM when completing the two trials. The stretching regimen accomplished that goal, verified by stretched trial having higher PROM and AROM as compared to non-stretched trial (116.9 ± 10.7ovs. 101.4 ± 12.2o, p < 0.05; 78.2 ± 11.4ovs. 69.6 ± 12.6o, p < 0.05, respectively). Agonist abduction force was not affected by targeted stretching of the antagonist musculature (stretched trial = 61.5 ± 22.4 N, non-stretched trial = 59.0 ± 24.1 N, p = 0.17). Similarly, energy expenditure associated with the standing hip abduction task remained unchanged (stretched trial = 19.4 ± 5.8 kJ∙min-1, non-stretched trial = 20.4 ± 6.1 kJ∙min-1, p = 0.15). CONCLUSION: Increasing the antagonist ROM did not alter the energy expenditure or peak force production associated with a novel leg abduction task. Stretching was shown to be neither beneficial nor detrimental.

Supported by Pacific University Grant.

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