Affiliations: [a] Department of Physical Therapy and Graduate Institute
of Rehabilitation Science, Chang Gung University, Taoyuan, Taiwan | [b] The Graduate Institute of Sports Injury Prevention,
National College of Physical Education and Sports, Taoyuan, Taiwan | [c] Institute and Faculty of Physical Therapy, National
Taiwan University, Taipei, Taiwan
Note: [] Address for correspondence: Yang Hua Lin, Ph.D, Graduate
Institute of Rehabilitation Science, Chang Gung University, 259, Wen-Hwa 1st
Rd., Kweishan, Taoyuan, Taiwan, 333. Tel.: +886 3 2118800 5438; Fax: +886 3
2118700; E-mail: linyh@mail.cgu.edu.tw
Abstract: Objective: To investigate whether muscle fatigue of ankle invertors
and evertors reduces the ability to detect inversion and eversion angles in
subjects with an ankle proprioceptive deficit. Design: A cross-sectional
before-after study with repeated measures design. Setting: Research
laboratory. Subjects: Thirty young adults with defective passive joint
sense of ankle inversion were recruited into this study and compared with 30
similar controls without ankle proprioceptive deficits. Interventions:
Muscle fatigue of ankle invertors and evertors was defined as occuring when the
maximal isokinetic torque declined to below 50% of the peak torque. Main measures: The absolute differences between the angles detected and
assigned, with target angles at inversion 10°, inversion 20°,
and eversion 10° trialled in random orders. Results: Proprioceptive deficits and muscle fatigue of ankle inversion and eversion had
a significant interaction with the ability to detect small amplitude target
angles. Detecting 10° of ankle eversion and inversion showed
significantly greater errors than for 20° of ankle inversion.
Following muscle fatigue or in subjects with proprioceptive deficits there were
greater errors in detecting small amplitudes of ankle positions (10°
of ankle inversion and eversion). Conclusions: The potential deleterious
effects of fatigue and proprioceptive deficits on the ability to detect the
small range of lateral movements of ankle joint was addressed in this
investigation.. Fatigue worsens chronic proprioceptive ankle deficits and hence
may enhance the risk of injury.
Keywords: Ankle injury, muscle fatigue, position sense, proprioceptive deficits
