Different patterns of blood flow response in the trapezius muscle following needle stimulation (acupuncture) between healthy subjects and patients with fibromyalgia and work‐related trapezius myalgia

Abstract

Needle stimulation (acupuncture) has recently been shown to increase blood flow in the tibialis anterior muscle and overlying skin in healthy subjects (HS) and patients with fibromyalgia (FM). The aim of the present study was to examine the effect of needle stimulation on local blood flow in the trapezius muscle and overlying skin in HS and two groups of patients suffering from chronic pain in the trapezius muscle, i.e., FM and work-related trapezius myalgia (TM) patients. Two modes of needling, deep muscle stimulation (Deep) and subcutaneous needle insertion (SC), were performed at the upper part of the shoulder and blood flow was monitored for 60 min post-stimulation. Blood flow changes were measured non-invasively by using a new application of photoplethysmography. Increased blood flow in the trapezius muscle and overlying skin was found in all three groups following both Deep and SC. In HS, Deep was superior to SC in increasing skin and muscle blood flow, whereas in FM, SC was as effective as, or even more effective, than Deep. In the severely affected TM patients, no differences were found between the stimuli, and generally, a lesser blood flow response to the stimuli was found. At Deep, the muscle blood flow increase was significantly larger in HS, compared to the two patient groups. Positive correlations were found between muscle blood flow at Deep and pressure pain threshold in the trapezius muscle, neck movement and pain experienced at the stimulation, and negative correlations were found with spontaneous pain-related variables, symptom duration and age, pointing to less favorable results with worsening of symptoms, and to the importance of nociceptor activation in blood flow increase. It was hypothesized that the different patterns of muscle blood flow response to the needling may mirror a state of increased sympathetic activity and a generalized hypersensitivity in the patients. The intensity of stimulation should be taken into consideration when applying local needle stimulation (acupuncture) in order to increase the trapezius muscle blood flow in chronic pain conditions.

Autonomic Regulation in Musculoskeletal Pain

“…Impaired blood flow to the pain region has been observed in persons with both chronic regional and widespread pain during various provocations, e.g., cold water, needle stimulation by acupuncture, and static or dynamic contractions (Acero et al 1999;Larsson et al 1999;Sandberg et al 2005;Elvin et al 2006;; for comprehensive reviews on this topic see Passatore and Roatta (2006) and Vierck (2006).…”

The Effect of Acupuncture on Muscle Blood Volume and Oxygenation

“…Several studies have shown that acupuncture can be a useful modality for treating pain due to muscle spasms (Lundeberg et al, 1988: Sandberg et al, 2005: Inoue et al, 2006. It is believed that shoulder stiffness is caused primarily by restriction of blood flow to the working muscles where accumulated metabolites appear to activate sympathetic vasoconstrictors.…”

“…It is believed that shoulder stiffness is caused primarily by restriction of blood flow to the working muscles where accumulated metabolites appear to activate sympathetic vasoconstrictors. Acupuncture stimulation (AS) is reported to increase local tissue blood flow in animals (Noguchi et al, 1999;Sato et al, 2000;Uchida et al, 2007) and humans (Sakai 2005;Sandberg et al, 2003;Sandberg et al, 2005) and are applicable in therapeutic interventions of shoulder stiffness. The effects of acupuncture include neural, endocrinological, cardiovascular, and immunological functions.…”

Effects of Hot Water Baths Containing Carbon Dioxide and 3-Octylphthalide on Work-Related Chronic Shoulder-Neck Muscle Pain

“…For example, trophotherapy and pharmacotherapy 3) , physical therapy using massage 4) , acupuncture, and moxibustion or electrotherapy treatment 5 ) . Balneotherapy, which is a commonly used thermotherapy, has good prospects as a useful treatment for essential chronic shoulder-neck pain, because it has an underlying effect on the systemic circulation 6) .…”

“…With regard to muscle tension, previous studies have measured muscle hardness using various types of devices to identify the level of tension in the trapezius, because the hardness is thought to be closely related to the subjective symptoms 16) . For blood circulation analysis, direct measurement of dynamic flow using Laser-Doppler flowmetry 5,17) and non-invasive measurement of total hemoglobin volume and tissue oxygen saturation using nearinfrared spectroscopy (NIRS) have been reported 18) . To quantify pain intensity, the relationship between subjective symptoms and pressure pain has previously been used 19) .…”