Biomedical subjects

Peter Gibbons

Publications and source records attributed to Peter Gibbons.

3 recordsLinked to original sources

PubMed2004

Paraspinal muscles and intervertebral dysfunction: part one.

BACKGROUND: One of the diagnostic characteristics of the manipulable spinal lesion--a musculoskeletal disturbance detected by manual palpation and corrected with manipulation--is said to be altered segmental tissue texture. Various manual therapy authors have speculated on the possible nature of this tissue change, with some authors hypothesizing that it represents deep segmental muscle overactivity. OBJECTIVES: To review the literature relating to the detection and nature of altered paraspinal tissue texture, proposed explanations for altered tissue texture, evidence for the plausibility of paraspinal muscle spasm, and evidence of muscle dysfunction associated with low back pain (LBP). DATA SOURCE: MEDLINE and CINAHL databases were searched using various combinations of the keywords paraspinal, muscle, palpation, EMG, spine, low back pain, pain, myofascial, hardness, manipulation, reliability, and somatic dysfunction, along with searching the bibliographies of selected articles and textbooks. DATA EXTRACTION: All relevant data were used. RESULTS: Little direct evidence exists for the nature of abnormal paraspinal tissue texture detected by palpation. Palpation for tenderness is more reliable than palpation for tissue texture change. Indirect evidence from animal studies and experimental muscle inflammation support the plausibility of protective paraspinal muscle contraction. Increased paraspinal electromyographic (EMG) activity observed in subjects with LBP appears to be a result of voluntary and nonvoluntary changes in motor control, modified by psychophysiological responses to perceived stress rather than a simple protective reflex. CONCLUSION: Although little direct evidence exists of the nature of clinically detected paraspinal tissue texture change, the concept of reactive muscle contraction appears plausible. Increased paraspinal EMG activity associated with LBP does not appear to be mediated by a simple protective reflex.

Electromyography↗

PubMed2004

Paraspinal muscles and intervertebral dysfunction: part two.

BACKGROUND: One of the diagnostic characteristics of the manipulable spinal lesion--a musculoskeletal disturbance that is claimed to be detected with manual palpation and corrected with manipulation--is said to be altered segmental tissue texture. Little evidence for the nature of abnormal paraspinal tissue texture exists, but indirect evidence from experimental studies supports the plausibility of the concept of protective muscle spasm, although investigations of increased paraspinal electromyography (EMG) associated with low back pain suggests complex changes in motor control rather than simple protective reflexes. OBJECTIVES: To review the literature for evidence that may support or refute proposed explanations for clinically observed altered paraspinal tissue texture associated with the manipulable spinal lesion. This review aims to highlight areas that require further research and make recommendations for future studies. Data Source MEDLINE and CINAHL databases were searched using various combinations of the keywords paraspinal, muscle, palpation, EMG, spine, low back pain, pain, myofascial, hardness, manipulation, reliability, and somatic dysfunction, along with searching the bibliographies of selected articles and textbooks. Data Extraction All relevant data were used. RESULTS: Decreased paraspinal muscle activity and strength associated with low back pain is well established, and there is evidence of changes in muscle fiber composition and localized selective multifidus atrophy. Disturbances in microcirculation have been implicated in nonparaspinal muscle pain. The effect of spinal manipulation on paraspinal EMG activity is inconclusive but promising. CONCLUSION: Little direct evidence exists to support the existence or nature of paraspinal tissue texture change that is claimed to be detected with palpation. The proposal of segmental reflex paraspinal muscle contraction was not supported, at least in association with low back pain. There appears to be a complex relationship between deep paraspinal muscle inhibition during dynamic activity and nonvoluntary guarding behavior during static activity. The relationship between these findings and palpable tissue change is speculative, but increased activity, decreased activity, or both may be responsible for paraspinal tissues detected as abnormal with palpation. Recommendations are outlined for future research.

Atrophy↗

PubMedDate not supplied

The electromyographic activity of thoracic paraspinal muscles identified as abnormal with palpation.

OBJECTIVE: The aim of this study was to compare the electromyographic (EMG) activity of deep muscles in the thoracic paravertebral gutter (PVG) detected as abnormal to palpation (AbPT) and reported as tender by the subject with muscles underlying nontender (NT), normal to palpation sites under various experimental conditions. METHODS: Twelve subjects (mean age, 25.42 years; range, 22-43 years) participated in this study. Fine-wire, bipolar intramuscular electrodes were inserted, under real-time ultrasonic guidance, into the deep paravertebral muscle mass underlying 1 AbPT and 2 NT sites (1 segment above and below the AbPT site) in the thoracic PVG regions. Electromyographic activity was recorded under the following conditions: resting prone, prone active trunk extension, application of pressure (300 kPa) to adjacent spinous processes, resting seated, passive and active seated trunk rotation, and supporting 2-kg weights in outstretched arms. RESULTS: Mean EMG activity was highest at the AbPT site, relative to NT sites, under all conditions, with a significant between-group effect of site (F2,31 = 4.13, P = .03) and large between-group effect size (eta2 = 0.21). There was also a trend for lower percentage change from baseline resting at the AbPT sites, relative to the NT sites, in response to the demand of other conditions. There were large variations in EMG activity within and between individuals, and large SDs accompanied the mean values of EMG activity in all cases. CONCLUSION: Increased motor activity may be a contributing factor to tissue changes in the PVG detected with palpation. However, caution must be used when interpreting these results because of the large variations, small sample size, and issues associated with EMG normalization.

Adult↗