Author(s): HUGHES, J.1, HOLZHAUER, L.2, JULIAN, R.2,3, Institution: CARDIFF METROPOLITAN UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 1196

INTRODUCTION:
Team sports often require high volumes of acceleration, deceleration, and changes in direction that lead to fatigue through intense force generation and braking, increasing the risk of hamstring injuries1, 2. The hips ability to generate substantial force is crucial for hamstring support during the stance phase of running, particularly at higher speeds and during sprinting3. The gluteus maximus, identified as a compensatory hip extensor, can protect the hamstrings from excessive strain under fatigue4. Therefore, evaluating the gluteus maximus capacity is vital to mitigate non-contact injuries linked to fatigue. This paper presents a novel unilateral isometric hip-extension strength test for assessing posterior-chain muscle activity.
METHODS:
Muscle activity of biceps femoris, gluteus maximus, semitendinosus, and gastrocnemius were assessed in eight participants (age: 21.9 ± 2.4y) using normalized sEMG during maximal voluntary contraction for the stance and pull leg. The study used a 2 x 4 x 2 (task condition x muscle group x leg dominance) repeated measures factorial ANOVA design.
RESULTS:
A significant main effect of the task condition (p < .001, eta2 = .55), showed the pull leg had higher muscle activation than the stance leg. Muscle activation varied significantly across muscle groups when combined with the task condition (p < .001, eta2 = .49), especially in the hamstrings of the pull leg. Leg dominance did not significantly affect muscle activation patterns (p < .758, eta2 < .01).
CONCLUSION:
The test effectively assessed hamstring activation, particularly in the pull leg, and demonstrated its utility in independently monitoring each leg. It could reveal asymmetries in leg strength, potentially valuable in sports like football, where such differences are relevant. The influence of leg dominance on muscle activation was minimal, suggesting the test’s potential to highlight between-leg strength disparities.

REFERENCES
1. Thorborg, et al. (2013), 2. Hägglund, et al. (2013), 3. Schache, et al. (2014), Edouard, et al. (2018)