Abstract
Shear wave elastography (SWE) has been used to assess muscle stiffness, but there is limited information on acute changes over time, particularly regarding how heating and stretching affect the intrinsic stiffness of the gastrocnemius. PURPOSE: to compare stiffness between neutral and relaxed ankle positions for the lateral head of the gastrocnemius (LG) and to evaluate whether passive heat alters muscle stiffness. A secondary aim is to assess stiffness changes in the LG over a 10-minute stretch, both with and without heat. METHODS: Thirteen subjects (4 men and 9 women) participated in this study. The mean age was 21.5 ± 2.5 years for men and 23.2 ± 4.2 years for women (age range = 19-48). Mean height was 175.9 ± 6.99 cm for men and 165.1 ± 12.7 cm for women, while mean weight was 73.4 ± 8.96 kg for men and 62.9 ± 9.68 kg for women. Participants lay prone with their ankles resting off the surface in a relaxed position. Baseline SWE measurements of the right and left LG were recorded in relaxed and neutral positions. The left ankle was fixed in a dorsiflexed position at the point of stretch tolerance for 10 minutes, with SWE assessed at one-minute intervals. SWE was then measured in both the relaxed and neutral ankle positions two minutes post-stretch. For the right leg, a clinical moist hot pack was applied to the right calf for 10 minutes, followed by SWE assessment. The right ankle was then stretched in the same manner as the left, with subsequent SWE measurements taken in the LG. RESULTS: at baseline, stiffness of the LG was significantly greater in the neutral ankle position than the relaxed position (t=11.0, p<.0001). Heat application resulted in a significant acute increase in stiffness for the neutral position only (p<.05 with SNK post-hoc analysis). A sustained stretch for 10 minutes showed a continuous decline in stiffness over time for both heat and no heat conditions with heated values being significantly lower than no heat (p=0.0053). CONCLUSION: Using SWE, we determined that the LG is stiffer in neutral ankle position than relaxed position. Applying passive heat acutely increases stiffness compared to no heat. Stretching over a 10-minute interval reduces stiffness in both conditions with lower levels of stiffness in the heated LG.
Recommended Citation
Thompson, Karissa; Skinner, Kaitlyn; Merrill, Ray M.; and Feland, Brent
(2024)
"Effects of Thermodynamics and Stretching on Lateral Gastrocnemius Muscle Stiffness via Shear Wave Elastography: A Pilot Study,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
Iss.
4, Article 107.
Available at:
https://digitalcommons.wku.edu/ijesab/vol14/iss4/107
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