Affiliations: [a] Department of Physical Therapy, Yeungnam University College, Hyunchung-ro, Nam-gu, Daegu 42415, Korea | [b] Department of Physical Therapy, College of Health Science, Cheongju University, Cheongwon-gu, Chungcheongbuk-do 28503, Korea
Correspondence:
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Corresponding author: Yonghyun Kwon, Department of Physical Therapy, Yeungnam University College, 170, Hyunchung-ro, Nam-gu, Daegu 42415, Korea. Tel.: +82 53 650 9702; Fax: +82 53 629 5048; E-mail: kwonpt@gmail.com.
Abstract: BACKGROUND: Many studies have investigated the correlation between muscle torque and joint position sense (JPS), but few studies have been performed on the correlation between torque ratio and JPS. OBJECTIVE: The aim of this study was to investigate JPS and muscle torque ratios of agonist and antagonist muscles in the ankle and knee joints of young adults. METHODS: A total of 38 right handed healthy participants, 12 males and 26 females, were recruited. All participants measured their peak torque of knee flexor/extensor and ankle dorsiflexor/plantar flexor by using a Biodex system. They also used the Biodex to assess the proprioception through active joint reposition sense test in knee and ankle joint. Peak torque of each muscle, agonist/antagonist torque ratio and JPS error were collected, and Pearson’s correlation analysis was used to examine correlations between peak torque, torque ratio and JPS error. RESULTS: For knee joints, correlations were found between flexion and extension torque, extension torque and torque ratio, and torque ratio and JPS error (r= 0.825/p= 0.000, r=-0.482/p= 0.002, and r=-0.685/p= 0.000, respectively). For ankle joints, correlations were found between dorsiflexion and plantar flexion torques, plantar flexion torque and torque ratio, plantar flexion torque and JPS, and torque ratio and JPS (r= 0.654/p= 0.000, r=-0.621/p= 0.000, r=-0.563/p= 0.000, and r=-0.761/p= 0.000, respectively). CONCLUSIONS: JPS error of lower extremity joint may be more related with agonist/antagonist torque ratio rather than peak torque. Therefore, people who will have training for reducing JPS error need to consider torque ratio, too.
Keywords: Torque ratio, joint position sense error, peak torque
