Affiliations: [a] Department of Health and Rehabilitation, Woosong University, Daejeon, Republic of Korea | [b] Department of Physical Medicine and Rehabilitation, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea | [c] Department of Physical therapy, Woosong University, Daejeon, Republic of Korea | [d] Woosong Institute of Rehabilitation Science, Daejeon, Republic of Korea
Correspondence:
[*]
Corresponding author: Wootaek Lim, Department of Physical Therapy, College of Health and Welfare, Woosong University, 171 Dongdaejeon-ro, Dong-gu, Daejeon, Republic of Korea. Tel.: +82 42 630 4624; Fax: +82 42 630 4611; E-mail: wootaeklimpt@wsu.ac.kr.
Abstract: BACKGROUND: Although the medial and lateral hamstrings are clearly distinct anatomically and have different functions in the transverse plane, they are often considered as one muscle during rehabilitation. OBJECTIVE: The purpose of the study was to compare the electromyographic (EMG) activity between the prone position and the supine position during maximal isometric contraction and to additionally confirm the effect of submaximal isometric contractions on EMG activity of medial and lateral hamstrings, and force. METHODS: In the prone position, EMG activities of the long head of biceps femoris (BFLH) and semitendinosus (ST) were measured during the maximal isometric contraction. In the supine position, hip extension force with EMG activity were measured during the maximal and the submaximal isometric contractions. RESULTS: EMG activity in the prone position was significantly decreased in the supine position. In the supine position, there was a significant difference between the BFLH and ST during the maximal isometric contraction, but not during the submaximal isometric contractions. CONCLUSIONS: The dependence on the hamstrings could be relatively lower during hip extensions. When the medial and lateral hamstrings are considered separately, the lateral hamstrings may show a more active response, with increased muscle length, in clinical practice.
