A relationship between altered postural control and injury has been reported in sports. Sensorimotor function serves a fundamental role in postural control and is not often studied in runners. Persons who sustain running injury may have altered sensorimotor function contributing to risk of injury or reinjury.
To determine if differences in knee and ankle proprioception or plantar sensation exist between injured and noninjured runners.
Retrospective case-control study.
Twenty runners with a history of lower-extremity overuse injury and 20 noninjured runners were examined. Injured runners were subcategorized into 2 groups based on site of injury: foot/ankle and knee/hip.
Main Outcome Measures:
Active absolute joint-repositioning error of the ankle at 20° inversion and 10° eversion and the knee at 15° and 40° flexion was assessed using an isokinetic dynamometer. Vibratory threshold at the calcaneus, arch, and great toe was determined for each subject using a handheld electric sensory threshold instrument.
Runners in the injured-foot/ankle group had increased absolute error during ankle-eversion repositioning (6.55° ± 3.58°) compared with those in the noninjured (4.04° ± 1.78°, P = .01) and the hip/knee (3.63° ± 2.2°, P = .01) groups. Runners in the injured group, as a whole, had greater sensitivity in the arch of the plantar surface (2.94 ± 0.52 V) than noninjured runners (2.38 ± 0.53 V, P = .02).
Differences in ankle-eversion proprioception between runners with a history of ankle and foot injuries and noninjured runners were observed. Runners with a history of injury also displayed an increased vibratory threshold in the arch region compared with noninjured runners. Poor ankle-joint-position sense and increased plantar sensitivity suggest altered sensorimotor function after injury. These factors may influence underlying postural control and contribute to altered loading responses commonly observed in injured runners.
Switlick and Kernozek are with the Dept of Health Professions, University of Wisconsin-La Crosse, La Crosse, WI. Meardon is with the Dept of Physical Therapy, East Carolina University, Greenville, NC. Address author correspondence to Thomas Kernozek at firstname.lastname@example.org.