A proposed experimental model of myofascial trigger points in human muscle after slow eccentric exercise

Pressure pain sensitivity and hardness along human normal and sensitized muscle

The spatial distribution of pressure sensitivity and muscle hardness was examined on normal muscle tissue and muscle tissue after induction of delayed onset muscle soreness (DOMS). The pressure sensitivity and muscle hardness were assessed at nine sites on the tibialis muscle from the proximal to distal tendon on two separate days. In total 37 healthy volunteers participated in three experiments. In the first experiment pressure pain threshold (PPT) and pressure pain tolerance (PPTO) were assessed. Decreased PPT and PPTO were found on day 2, 7 days after day 1. Proximal and distal stimulation sites were harder compared to muscle belly sites. In a second experiment two different probe sizes were used. Variation in PPT between the nine sites was found for the large probe with muscle belly being less sensitive to pressure stimulation compared to proximal and distal sites. The most proximal stimulation site was harder compared to muscle belly sites. In a third experiment PPT and muscle hardness were assessed before and 48 h after eccentric exercise. PPT at two muscle belly sites was significantly decreased during DOMS. No specific sites were harder during DOMS, the average muscle hardness across sites was however significantly increased. Decreased PPT and increased muscle hardness did not correlate. In conclusion, within subjects the pressure sensitivity varies along the musculoskeletal unit. In DOMS, specific muscle belly sites were more sensitive to pressure stimulation. Muscle-tendon sites were harder compared to muscle belly sites.

A musculoskeletal model of low grade connective tissue inflammation in patients with thyroid associated ophthalmopathy (TAO): the WOMED concept of lateral tension and its general implications in disease

Background

Low level connective tissue inflammation has been proposed to play a role in thyroid associated ophthalmopathy (TAO). The aim of this study was to investigate this postulate by a musculoskeletal approach together with biochemical parameters.

Methods

13 patients with TAO and 16 controls were examined. Erythrocyte levels of Zn, Cu, Ca²⁺, Mg, and Fe were determined. The musculoskeletal evaluation included observational data on body posture with emphasis on the orbit-head region. The angular foot position in the frontal plane was quantified following gait observation. The axial orientation of the legs and feet was evaluated in an unloaded supine position. Functional propioceptive tests based on stretch stimuli were done by using foot inversion and foot rotation.

Results

Alterations in the control group included neck tilt in 3 cases, asymmetrical foot angle during gait in 2, and a reaction to foot inversion in 5 cases. TAO patients presented facial asymmetry with displaced eye fissure inclination (mean 9.1°) as well as tilted head-on-neck position (mean 5.7°). A further asymmetry feature was external rotation of the legs and feet (mean 27°). Both foot inversion as well as foot rotation induced a condition of neuromuscular deficit. This condition could be regulated by gentle acupressure either on the lateral abdomen or the lateral ankle at the acupuncture points gall bladder 26 or bladder 62, respectively. In 5 patients, foot rotation produced a phenomenon of moving toes in the contra lateral foot. In addition foot rotation was accompanied by an audible tendon snapping. Lower erythrocyte Zn levels and altered correlations between Ca²⁺, Mg, and Fe were found in TAO.

Conclusion

This whole body observational study has revealed axial deviations and body asymmetry as well as the phenomenon of moving toes in TAO. The most common finding was an arch-like displacement of the body, i.e. eccentric position, with foot inversion and head tilt to the contra lateral side and tendon snapping. We propose that eccentric muscle action over time can be the basis for a low grade inflammatory condition. The general implications of this model and its relations to Zn and Se will be discussed.

How do acupuncture and moxibustion act? - Focusing on the progress in Japanese acupuncture research -

The mechanisms of action of acupuncture and moxibustion as reported by Japanese researchers are reviewed. The endogenous opioid-mediated mechanisms of electroacupuncture (EA) as used in China are well understood, but these are only one component of all mechanisms of acupuncture. These studies emphasize the similarity of the analgesic action of EA to various sensory inputs to the pain inhibition mechanisms. In Japanese acupuncture therapy, careful detection of the acupuncture points and fine needling technique with comfortable subjective sensation are considered important. The role of polymodal receptors (PMR) has been stressed based on the facts that PMRs are responsive to both acupuncture and moxibustion stimuli, thermal sensitivity is essential in moxibustion therapy, and the characteristics of acupuncture points and trigger points are similar to those of sensitized PMRs. Acupuncture and moxibustion are also known to affect neurons in the brain reward systems and blood flow in skin, muscle, and nerve. Axon reflexes mediated by PMRs might be a possible mechanism for the immediate action of acupuncture and moxibustion. Reports on the curative effects of acupuncture on various digestive and urological disorders are also reviewed briefly.

Effects of trigger point acupuncture on chronic low back pain in elderly patients--a sham-controlled randomised trial

INTRODUCTION

There is some evidence for the efficacy of acupuncture, but it remains unclear whether trigger point acupuncture is effective. Our objective was to evaluate the effects of trigger point acupuncture on pain and quality of life in chronic low back pain patients compared with sham acupuncture.

METHODS

Twenty-six consecutive out-patients (17 women, 9 men; age range: 65-91 years) from the Department of Orthopaedic Surgery, Meiji University of Oriental Medicine, with non-radiating low back pain for at least six months and normal neurological examination, were randomised to two groups. Each group received one phase of trigger point acupuncture and one of sham acupuncture with a three week washout period between them, over 12 weeks. Group A (n = 13) received trigger point acupuncture in the first phase and sham acupuncture in the second. Group B (n = 13) received the same interventions in the reverse order. Outcome measures were pain intensity (visual analogue scale, VAS) and Roland Morris Questionnaire.

RESULTS

Nineteen patients were included in the analysis. At the end of the first treatment phase, group A receiving trigger point acupuncture scored significantly lower VAS (P < 0.001) and Roland Morris Questionnaire scores (P < 0.01) than the sham control group. There were significant within-group reductions in pain in both groups during the trigger point acupuncture phase but not in the sham treatment phase. However, the beneficial effects were not sustained.

CONCLUSION

These results suggest that trigger point acupuncture may have greater short term effects on low back pain in elderly patients than sham acupuncture.

Randomised trial of trigger point acupuncture compared with other acupuncture for treatment of chronic neck pain

INTRODUCTION

There is some evidence for the efficacy of acupuncture in chronic neck pain (CNP) treatment, but it remains unclear which acupuncture modes are most effective. Objective was to evaluate the effects of trigger point acupuncture on pain and quality of life (QOL) in CNP patients compared to three other acupuncture treatments (acupoints, non-trigger point and sham treatment).

METHODS

Forty out-patients (29 women, 11 men; age range: 47-80 years) from the Department of Orthopaedic Surgery, Meiji University of Oriental Medicine, with non-radiating CNP for at least 6 months and normal neurological examination were randomised to one of four groups over 13 weeks. Each group received two phases of acupuncture treatment with an interval between them. The acupoint group (standard acupuncture; SA, n=10) received treatment at traditional acupoints for neck pain, the trigger point (TrP, n=10) and non-trigger point (non-TrP, n=10) groups received treatment at tenderness points for the same muscle, while the other acupuncture group received sham treatments on the trigger point (SH, n=10). Outcome measures were pain intensity (visual analogue scale; VAS 0-100mm) and disease specific questionnaire (neck disability index; NDI, 60-point scale).

RESULTS

After treatment, the TrP group reported less pain intensity and improved QOL compared to the SA or non-TrP group. There was significant reduction in pain intensity between the treatment and the interval for the TrP group (p<0.01, Dunnett's multiple test), but not for the SA or non-TrP group.

CONCLUSION

These results suggest that trigger point acupuncture therapy may be more effective on chronic neck pain in aged patients than the standard acupuncture therapy.

An expansion of Simons' integrated hypothesis of trigger point formation

Simons' integrated hypothesis proposed a model of trigger point (TrP) activation to explain known TrP phenomena, particularly endplate noise. We propose an expansion of this hypothesis to account for new experimental data and established muscle pathophysiology.