To determine overall handgrip strength (HGS), we assessed the short-term change of HGS after trigger point injection (TPI) in women with muscular pain in the upper extremities by comparison with established pain scales.

The study enrolled 50 female patients (FMS with MPS group: 29 patients with combined fibromyalgia [FMS] and myofascial pain syndrome [MPS]; MPS group: 21 patients with MPS) who presented with muscular pain in the upper extremities at Konyang University Hospital. In addition, a total of 9 healthy women (control group) were prospectively enrolled in the study. We surveyed the three groups using the following established pain scales: the Fibromyalgia Impact Questionnaire (FIQ), the 36-Item Short Form Health Survey (SF-36), and the Short Form McGill Pain Questionnaire (MPQ). HGS was measured in both hands of study participants using a handgrip dynamometer. We performed TPI (0.5% lidocaine, total 10 mL, injected at the pain site of upper extremities). After 20 minutes, we remeasured the patient's HGS and MPQ score.

ANOVA analysis was conducted among groups. Based on Tukey multiple comparison test, the majority of FIQ and SF-36 subscales, total FIQ and SF-36 scores, MPQ and HGS were significantly different between FMS with MPS and the other groups. There was no statistically significant difference between MPS and control groups. Higher HGS was positively associated with enhanced physical function, negatively associated with total FIQ and MPQ scores, and positively associated with the total SF-36 score calculated using Spearman correlation. Post-TPI MPQ decreased and HGS increased. In patient groups, a negative correlation was found between MPQ and HGS.

The HGS test might potentially be a complementary tool in assessing the short-term treatment effects of women with muscular pain in the upper extremities.