The current literature on the value of clinical evaluation for predicting time to return to sport (RTS) after acute hamstring injuries has not been systematically summarised. The aim of this study was to systematically review the literature on the prognostic value of clinical findings (patient history and physical examination) for time to RTS after acute hamstring injuries in athletes.
Two authors independently screened the search results and assessed risk of bias using the modified Quality in Prognosis Studies (QUIPS) tool for quality appraisal of prognosis studies. The authors used a best-evidence synthesis to determine the level of evidence. Sixteen studies were included, of which one study had a low risk of bias and 15 had a high risk of bias. Moderate evidence for an association with time to RTS was found for three clinical findings (visual analogue scale; pain at time of injury, self-predicted time to RTS and clinician predicted time to RTS). There was limited evidence for an association with time to RTS for seven clinical findings (muscle pain during everyday activities, popping sound at injury, forced to stop within 5 min, visual bruising at the site of injury, width (cm) of tenderness to palpation, pain on trunk flexion and pain on active knee flexion initially after injury). The remaining clinical findings revealed either conflicting evidence or limited evidence for an association with time to RTS.
There is at present no strong evidence that any clinical finding at baseline provides a valuable prognosis for time to RTS after an acute hamstring injury. There is moderate evidence that visual analogue scale pain at time of injury and predictions for time to RTS by the patient and the clinician are associated with time to RTS. The methodological quality of the current literature is characterised by a substantial risk of bias and reporting of RTS definitions and criteria for RTS were inconsistent. We provide recommendations that can guide the design of future studies.