Characteristicsofpatientswithmyofascialpainsyndromeofthelowback

Myofascial pain syndrome (MPS) is a regional pain disorder characterized by trigger points (MTrPs) in muscle tissue, but its role in low back pain remains poorly understood. While studies suggest 63.5-90% of low back pain patients may have MPS, there's limited research characterizing patients with MPS specifically in the lower back region. This lack of understanding hampers proper diagnosis and treatment of a potentially widespread condition.

Researchers conducted a cross-sectional study of 25 participants with chronic low back pain who had palpable trigger points confirmed by ultrasound examination. An osteopathic physician examined participants using physical palpation to identify trigger points, which were then verified using ultrasound to confirm hypo-echogenicity. Participants were categorized into four groups based on trigger point characteristics: Group 1 (active MTrPs with spontaneous pain and twitching), Group 2 (latent MTrPs with twitching but no spontaneous pain), Group 3 (atypical MTrPs with spontaneous pain but no twitching), and Group 4 (atypical MTrPs with neither spontaneous pain nor twitching). Researchers measured pain pressure threshold, physical function tests, quality of life questionnaires, and self-reported pain levels.

All 25 participants had multiple trigger points (average 4.36 trigger points per person), with 100% showing ultrasound confirmation of trigger point abnormalities. Participants with spontaneous pain (Groups 1 and 3) had significantly more trigger points (4.73 vs 3.80), higher current pain levels (3.80 vs 1.70), and worse pain in the past 24 hours (6.27 vs 3.10) compared to those without spontaneous pain. Interestingly, Group 3 (spontaneous pain without twitching) showed the worst physical function, highest pain levels, and most trigger points. The presence of spontaneous pain was more important for predicting poor physical function than the classic twitching response.

Female participants had longer pain duration and higher catastrophizing scores, while Black participants showed worse physical function and higher disability scores.

This study challenges traditional trigger point definitions by showing that spontaneous pain may be more clinically important than the classic twitching response for identifying problematic trigger points. The finding that all participants had multiple trigger points suggests MPS may be more common in low back pain than previously recognized. Clinicians should look for multiple trigger points in low back pain patients and focus on spontaneous pain rather than just twitching responses when assessing trigger points. The study also highlights the importance of considering sex and ethnicity in MPS assessment and treatment planning.