Chronic anterior compartment syndrome and deep peroneal nerve function.

OBJECTIVE: We hypothesized that athletes with chronic anterior exertional compartment syndrome (CAECS) would demonstrate an impairment in deep peroneal nerve function, as determined by electrodiagnostic studies or neuromuscular examination, either at baseline as compared with control athletes or after exercise.

DESIGN: Prospective, controlled study comparing athletes with CAECS to asymptomatic athletes.

SETTING: Outpatient, academic practice.

PARTICIPANTS: Ten athletes with CAECS were recruited sequentially over 1 year from an outpatient academic practice; diagnosis was confirmed by history, physical examination, and compartment pressure testing. Ten similarly aged control athletes were recruited from the surrounding facility.

INTERVENTION: Repetitive dorsiflexion exercise to the point of typical symptoms (CAECS subjects) or fatigue (control subjects).

MAIN OUTCOME MEASURES: Deep peroneal nerve conduction study velocity and amplitude; neuromuscular examination in the deep and superficial peroneal distributions.

RESULTS: Control subjects demonstrated a significant increase in peroneal motor amplitudes postexercise as compared with preexercise (6.3 +/- 2.2 mV preexercise to 8.2 +/- 3.1 mV postexercise; p = 0.033), but the CAECS subjects did not (8.8 +/- 2.6 to 8.9 +/- 2.1; p = 0.89). At baseline and postexercise, the subjects with CAECS demonstrated decreased vibratory sensation compared with the controls (p = 0.030 at baseline and 0.045 postexercise).

CONCLUSIONS: Athletes with CAECS demonstrate a decreased postexercise potentiation of the peroneal motor amplitude and a mild impairment in vibratory sensation; these findings may contribute to their sense of poor foot and ankle control. Further study is necessary before the absence of postexercise potentiation of the peroneal motor amplitude may be considered a diagnostic sign of CAECS.