ANKLE JOINT PROPRIOCEPTION AFTER AN ACHILLES TENDON RUPTURE

Researchers have suggested that foot position sense (i.e., proprioception) may be inherently poor in some persons and that poor ankle joint proprioception may increase the risk of an Achilles tendon rupture. PURPOSE To examine if ankle joint proprioception of the involved and uninvolved limbs of persons with a previous history of an Achilles tendon rupture is different than matched controls. METHODS Twenty persons (44.8 ± 13.9 yrs) with a unilateral rupture that was surgically repaired volunteered. All subjects had ruptured their Achilles tendon more than one-year prior to the study and 14 of the 20 ruptures occurred five years or less from the day of testing. A second group of twenty persons (44.2 ± 13.8 yrs) with no prior ankle injuries were matched to the experimental group using age, height, mass, calf circumference, body composition, and activity level as matching criteria. Proprioception was tested with a position-matching protocol using electrogoniometers attached to the ankles. Errors were calculated as the absolute and relative differences between target and estimated angles. Error measurements were compared within and between limbs using an alpha level of 0.05 to determine significance. RESULTS Error measurements were not different within groups (P > 0.63); however, between groups, absolute errors for the involved and uninvolved limbs of the experimental group were 27% and 31% greater respectively, than values for the control group (1.35 ± 0.5° and 1.39 ± 0.5° vs. 1.06 ± 0.4°, P < 0.04). Relative errors for the experimental group were not significantly different from the control group values (P > 0.62). CONCLUSION Persons with a previous history of an Achilles tendon rupture display proprioception deficits in the involved and uninvolved limb in comparison to matched controls. These data support the contention that an Achilles tendon rupture may be related to poor ankle joint proprioception. Supported by a faculty research grant from Utah State University