Effects of Eccentric Nordic Hamstring Exercise on Fascicle Length in Females

<p>The eccentric Nordic hamstring exercise (NHE) may be useful for increasing fascicle length (FL) of the bicep femoris long head and reduce the risk of hamstring strain injury. Compared to changes in hamstring strength, FL has been shown to reduce the risk of injury to a greater extent. While previous studies have investigated the eccentric NHE on FL, many lack control groups, female participants, and have not measured performance outcomes. Our aim was to examine the effect of 6-weeks of NHE on FL and measures of performance in females. Seven recreationally active females (age: 22.43 ± 2.99 years; BMI: 20.8 ± 4.14 kg/m2 ), were allocated into either a concentric only (control, n = 2) or eccentric only (n = 5) NHE group and completed 6-weeks of twice weekly NHE training. Outcome measures were assessed at baseline and post-intervention and included: bicep femoris FL and pennation angle (measured via 2D ultrasound), lower body isokinetic strength, and countermovement jump height. Independent samples Mann-Whitney U test were used to assess whether the change in the outcome variables pre-to-post intervention were different between the groups. Although not statistically significant (p>0.05), the eccentric group demonstrated increases in FL (median = 1.24cm) and decrease in pennation angle (median = -0.73°) compared to females in the control concentric group who showed a decrease in FL (median = -0.61cm) and increase in pennation angle (median = 1.38°). Additionally, there were non-statistically significant changes in isokinetic strength and countermovement jump for both groups pre-to-post intervention. Our findings suggest the eccentric NHE may be effective for increasing FL in females.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Health and Human Performance

Year dc:date.available

2023

Author dc:creator

• Triemstra, Sarah J

Contributors dc:contributor

• Megan Nelson

• Eccentric
• Nordic hamstring exercise
• fascicle length
• pennation angle
• muscle architecture
• hamstring strain injury
• females
• strength
• countermovement jump
• Sports Sciences

Repository record dc:identifier

https://commons.nmu.edu/theses/748

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1793