Context: Predicting when an athlete can return to sport after muscle injury is a major concern.
Objective: To determine whether combining objective clinical and ultrasound findings at presentation accurately predicted time to sport resumption in athletes with muscle injuries.
Design: Cohort study.
Setting: Sports medicine clinic.
Patients or other participants: A total of 93 consecutive patients, 87 male and 6 female, were seen over a 1-year period for sudden-onset muscle pain while engaging in a sporting activity within the last 5 days and inability to continue the training session or game.
Intervention(s): Standardized physical examination and sonogram.
Main outcome measure(s): Statistical associations between clinical and sonographic features at presentation and time to sport resumption (<40 days or ≥ 40 days) were evaluated using multivariate models. Correlations between time to sport resumption predicted by a sports medicine specialist and actual time to sport resumption were evaluated using the Spearman rank correlation coefficient.
Results: The 93 patients had 95 injuries, caused by muscle contraction in 86 cases and impact in 9 cases. Only 7 injuries had normal sonogram findings. Late sport resumption was associated with 4 clinical criteria (bruising, tenderness to palpation, range-of-motion limitation compared with the other limb, and increased pain with isometric contraction during passive limb straightening) and 4 sonographic criteria (disorganized fibrous tissue, intramuscular hematoma, intermuscular hematoma, and power Doppler signal). The Spearman rank correlation coefficient between predicted and actual times was 0.669 (P < .0001) for mild exercise resumption and 0.804 (P < .0001) for full sport resumption.
Conclusion: A combination of physical and sonographic data collected during the acute phase of sport-related muscle injury was effective in predicting time to sport resumption.