How To Diagnose Lateral Ankle Injuries

By Remy Ardizzone, DPM, and Ronald L. Valmassy, DPM

Recognizing Cases Of Functional Instability

   Additionally, a subset of patients may have negative stress exams but still demonstrate frequent minor inversion industries and a sense of instability to the ankle. This condition describes functional instability as opposed to mechanical instability.5,8,19,20 Under these circumstances, the ligaments may only have healed in a somewhat slightly loosened position but the patient has failed to re-establish the proprioceptive connection to the brain.21 Proprioceptive fibers are embedded within the lateral collateral ankle ligaments and sustain injury along with the ligament itself.8,21,22    One may assess proprioception in these patients by using a modified Rhomberg test. The patient stands on the normal ankle with his or her eyes open and then closed. Repeat this procedure on the symptomatic limb. Alternatively, the patient may rise onto the ball of the affected foot and perform five single leg hops.5-8 One of the key components of physical therapy is to reestablish these proprioceptive connections so the patient senses uneven surfaces and can recruit other muscles to stabilize the ankle and avoid inversion injury.23,24    Other contributors to functional instability include impaired joint position sense, delayed peroneal muscle reaction time, altered common peroneal nerve function and muscle weakness.5,8

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