Influence of the temporomandibular joint on range of motion of the hip joint in patients with complex regional pain syndrome.

Objective: This study evaluated if patients with complex regional pain syndrome (CRPS) would have an increase in range of motion (ROM) after myofascial release and a similar ROM decrease after jaw clenching, whereas in healthy subjects these effects would be minimal or nonexistent.
Methods: Documentation of patients with CRPS (n = 20) was established using the research diagnostic criteria for CRPS, questionnaires, average pain intensity for the past 4 weeks, and the temporomandibular index (TMI). Healthy subjects (n = 20, controls) also underwent the same testing. Hip ROM (alpha angle) was measured at 3 time points as follows: baseline (t1), after myofascial release of the temporomandibular joint (t2), and after jaw clenching for 90 seconds (t3). Comparison of the CRPS and control groups was made using t tests.
Results: Mean TMI total score and mean pain reported for the last 4 weeks were significantly different between the 2 groups (P < .0005). Hip ROM at t1 was always slightly higher compared to t3, but t2 was always lower in value compared to t1 or t3 for both groups. The differences of all hip ROM values between the groups were significant (P < .0005). Moreover, the difference between t1 or t3 and t2 was significantly different within the CRPS group (t1 = 48.7 degrees ; t2 = 35.8 degrees ; P < .0005).
Conclusions: The results suggest that temporomandibular joint dysfunction plays an important role in the restriction of hip motion experienced by patients with CRPS, which indicated a connectedness between these 2 regions of the body.