Myofascial trigger points, pain, disability, and sleep quality in patients with chronic nonspecific low back pain.

OBJECTIVE: To investigate the difference in the presence of trigger points (TrPs) between patients with chronic nonspecific low back pain (LBP) and healthy people, and to determine the relationship of TrPs with the intensity of ongoing pain, disability, and sleep quality. DESIGN: A cross-sectional study. SETTING: The role of TrPs in LBP has not been determined. PATIENTS: Forty-two patients with nonspecific LBP (50% women), aged 23-55 years old, and 42 age- and sex-matched controls participated. OUTCOME MEASURES: TrPs were bilaterally explored within the quadratus lumborum, iliocostalis lumborum, psoas, piriformis, gluteus minimus, and gluteus medius muscles in a blinded design. TrPs were considered active if the subject recognized the local and referred pain as familiar symptoms, and TrPs were considered latent if the pain was not recognized as a familiar symptom. Pain measures were collected with a numerical pain rate scale, disability was assessed with the Roland-Morris questionnaire, and sleep quality was determined with the Pittsburgh Sleep Quality Index. RESULTS: Patients with nonspecific LBP exhibited a greater disability and worse sleep quality than healthy controls (P < 0.001). Patients with nonspecific LBP exhibited a mean of 3.5 ± 2.3 active TrPs. Further, patients with nonspecific LBP showed a greater (P < 0.001) number of latent TrPs (mean: 2.0 ± 1.5) than healthy controls (mean: 1.0 ± 1.5). Active TrPs in the quadratus lumborum, iliocostalis lumborum, and gluteus medius muscles were the most prevalent in patients with nonspecific LBP. A greater number of active TrPs was associated with higher pain intensity (rs = 0.602; P < 0.001) and worse sleep quality (rs = 0.338; P = 0.03). CONCLUSIONS: The local and referred pain elicited by active TrPs in the back and hip muscles contributes to pain symptoms in nonspecific LBP. Patients had higher disability and worse sleep quality than controls. The number of active TrPs was associated with pain intensity and sleep quality. It is possible that a complex interaction among these factors is present in patients with nonspecific LBP.

Myofascial trigger points, pain, disability, and sleep quality in individuals with mechanical neck pain.

OBJECTIVE: The purpose of this study was to investigate the presence of active myofascial trigger points (MTrPs) in a greater number of muscles than previous studies and the relation between the presence of MTrPs, the intensity of pain, disability, and sleep quality in mechanical neck pain. METHODS: Fifteen patients with mechanical neck pain (80% women) and 12 comparable controls participated. Myofascial trigger points were bilaterally explored in the upper trapezius, splenius capitis, semispinalis capitis, sternocleidomastoid, levator scapulae, and scalene muscles in a blinded design. Myofascial trigger points were considered active if the subject recognized the elicited referred pain as a familiar symptom. Myofascial trigger points were considered latent if the elicited referred pain was not recognized as a symptom. Pain was collected with a numerical pain rate scale (0-10); disability was assessed with Neck Disability Index; and sleep quality, with the Pittsburgh Sleep Quality Index. RESULTS: Patients exhibited a greater disability and worse sleep quality than controls (P < .001). The Pittsburgh Sleep Quality Index score was associated with the worst intensity of pain (r = 0.589; P = .021) and disability (r = 0.552; P = .033). Patients showed a greater (P = .002) number of active MTrPs (mean, 2 ± 2) and similar number (P = .505) of latent MTrPs (1.6 ± 1.4) than controls (latent MTrPs, 1.3 ± 1.4). No significant association between the number of latent or active MTrPs and pain, disability, or sleep quality was found. CONCLUSIONS: The referred pain elicited by active MTrPs in the neck and shoulder muscles contributed to symptoms in mechanical neck pain. Patients exhibited higher disability and worse sleep quality than controls. Sleep quality was associated with pain intensity and disability. No association between active MTrPs and the intensity of pain, disability, or sleep quality was found.