Term of Award

Spring 2025

Degree Name

Master of Science in Kinesiology (M.S.)

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Health Sciences and Kinesiology

Committee Chair

NICHOLAS SIEKIRK

Committee Member 1

Emily Langford

Committee Member 2

Li Li

Abstract

Hamstring strain injuries are among the most common musculoskeletal injuries in sports with high recurrence rates. The Nordic hamstring exercise (NHE) is a commonly used eccentric exercise intervention to reduce injury risk but has generated controversy regarding its utility due to limited sport specificity. Research examining how NHE performance affects its efficacy remains scarce. Therefore, this study investigated whether accelerometry data could describe the loss of active eccentric control (Q2) and if there is an interaction between leg preference and repetition on time to Q2. METHODS: Thirty college-aged students with >3 months of resistance training experience (1-2x/week). were recruited. Participants completed active range of motion and isokinetic strength assessments, followed by three NHE repetitions for analysis. Visual and computational analyses of Q2 were conducted using processed accelerometry data. RESULTS: Significant differences existed between visual (M = 3.84, SD = 2.06, 95% CI = 3.45s to 4.24s) and computational (M = 4.19, SD = 2.17, 95% CI = 3.77s to 4.60s) Q2 determinations (p < 0.001). A significant main effect for repetition was observed in both visual (p < 0.001) and computational (p = 0.004) time to Q2. For visual analysis, post hoc comparisons revealed that rep 2 Q2 (M = 4.36s) occurred 0.67s later than rep 3 Q2 (M = 3.69s). Similarly, post hoc comparisons for the computational analysis revealed that rep 2 Q2 (M = 4.63s) occurred an average of 0.64s later than rep 3 Q2 (M = 3.99s). CONCLUSION: While significant differences were observed between the visual and computational Q2 determinations, both revealed identical trends between repetitions. The time to Q2 was longer for repetition 2 than for repetition 3, suggesting that the performance of the NHE is variable by repetition. These findings highlight potential fatigue-related decrements in eccentric control during repeated NHE performance, which may inform exercise prescription strategies for hamstring injury intervention programs.

OCLC Number

1520502012

Research Data and Supplementary Material

No

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