Referred pain from myofascial trigger points in head, neck, shoulder, and arm muscles reproduces pain symptoms in blue-collar (manual) and white-collar (office) workers
The Clinical Journal of Pain, 06/12/2012
Fernandez–de–las–Penas C et al. – Blue–collar and white–collar workers exhibited a similar number of TrPs in the upper quadrant musculature. The referred pain elicited by active TrPs reproduced the overall pain pattern. The distribution of TrPs was not significantly different between groups. Clinicians should examine for the presence of muscle TrPs in blue–collar and white–collar workers.
Methods- Sixteen (62% women) blue–collar and 19 (75% women) white–collar workers were included in this study.
- TrPs in the temporalis, masseter, upper trapezius, sternocleidomastoid, splenius capitis, oblique capitis inferior, levator scapulae, scalene, pectoralis major, deltoid, infraspinatus, extensor carpi radialis brevis and longus, extensor digitorum communis, and supinator muscles were examined bilaterally (hyper–sensible tender spot within a palpable taut band, local twitch response with snapping palpation, and elicited referred pain pattern with palpation) by experienced assessors blinded to the participants’ condition.
- TrPs were considered active when the local and referred pain reproduced any symptom and the patient recognized the pain as familiar.
- The referred pain areas were drawn on anatomic maps, digitized, and measured.
- Blue–collar workers had a mean of 6 (SD: 3) active and 10 (SD: 5) latent TrPs, whereas white–collar workers had a mean of 6 (SD: 4) active and 11 (SD: 6) latent TrPs (P>0.548).
- No significant differences in the distribution of active and latent TrPs in the analyzed muscles between groups were found.
- Active TrPs in the upper trapezius, infraspinatus, levator scapulae, and extensor carpi radialis brevis muscles were the most prevalent in both groups.
- Significant differences in referred pain areas between muscles (P<0.001) were found; pectoralis major, infraspinatus, upper trapezius, and scalene muscles showed the largest referred pain areas (P<0.01), whereas the temporalis, masseter, and splenius capitis muscles showed the smallest (P<0.05).
- The combination of the referred pain from TrPs reproduced the overall clinical pain area in all participants.
