Summary

In a prospective cohort study of acute hamstring injuries, the accuracy of injury location was better determined by physician palpation compared to patient-reported pain, while the length of palpation pain only weakly correlated with oedema length on MRI.

Abstract

Objectives: 1） To compare patient-reported and palpation-identified pain locations with the primary injury site on MRI. 2） To examine the relationship between palpation pain length and edema length on MRI

Method

This cross-sectional study included patients with acute hamstring injuries. Maximal pain location was identified by (1) the patient (self-reported group) or (2) palpation during clinical examination (palpation-assessed group). A sports physician measured the proximal-to-distal length of palpation pain, and a radiologist identified the primary injury site and edema length on MRI. Distances between pain sites and injury locations were analyzed, and lengths of palpation pain and edema were compared using linear regression and Spearman's correlation.

Results

The study included 28 patients in the self-reported group and 53 in the palpation group. The palpation group showed a closer match to the primary injury site on MRI than the self-reported group (p = 0.058, 95% CI [0.02, 0.96], CLES = 0.615). Edema length was significantly greater than palpation pain length (p < 0.001, Cliff’s Delta = 0.61, 95% CI [0.44, 0.74], CLES = 0.80). A weak correlation was found between palpation pain length and edema length (Spearman's r = 0.22, 95% CI [0.01, 0.41], R² = 0.04).

Conclusion

The location of maximal pain on palpation by a physician is more accurate than the patient's subjective report. The length of pain on palpation is shorter than oedema on MRI and they are only poorly correlated.