Barbara I. Polus

Muscle activation patterns in the scapular positioning muscles during loaded scapular plane elevation: The effects of latent myofascial trigger points

BACKGROUND Latent Myofascial Trigger Points are pain-free neuromuscular lesions that have been found to affect muscle activation patterns in the unloaded state. The aim was to extend these observations to loaded motion by investigating muscle activation patterns in upward scapular rotator muscles (upper and lower trapezius and serratus anterior) hosting Latent Myofascial Trigger Points simultaneously with lesion-free synergists for shoulder abduction (infraspinatus and middle deltoid). This approach allowed examination of the effects of these lesions on both their hosts and their lesion-free synergists in order to understand their effects on the performance of shoulder abduction. METHODS Surface electromyography was employed to measure the timing of onset of muscle activation of the upper and lower trapezius and serratus anterior (upward scapular rotators), infraspinatus (rotator cuff) and middle deltoid (abductor of the arm) initially without load and then with light (1-4 kg) dumbbells. Comparisons were made between control (no Latent Trigger Points; n=14) and Latent Trigger Point (n=28) groups. FINDINGS The control group displayed a relatively stable sequence of muscle activation that was significantly different in timing and variability to that of the Latent Trigger Point group in all muscles except middle deltoid (all P<0.05). The Latent Trigger Point group muscle activation pattern under load was inconsistent, with the only common feature being the early activation of the infraspinatus. INTERPRETATION The presence of Latent Trigger Points in upward scapular rotators alters the muscle activation pattern during scapular plane elevation, potentially predisposing to overuse conditions including impingement syndrome, rotator cuff pathology and myofascial pain.

Acupuncture, chiropractic and osteopathy use in Australia: a national population survey

BackgroundThere have been no published national studies on the use in Australia of the manipulative therapies, acupuncture, chiropractic or osteopathy, or on matters including the purposes for which these therapies are used, treatment outcomes and the socio-demographic characteristics of users.MethodsThis study on the three manipulative therapies was a component of a broader investigation on the use of complementary and alternative therapies. For this we conducted a cross-sectional, population survey on a representative sample of 1,067 adults from the six states and two territories of Australia in 2005 by computer-assisted telephone interviews. The sample was recruited by random digit dialling.ResultsOver a 12-month period, approximately one in four adult Australians used either acupuncture (9.2%), chiropractic (16.1%) or osteopathy (4.6%) at least once. It is estimated that, adult Australians made 32.3 million visits to acupuncturists, chiropractors and osteopaths, incurring personal expenditure estimated to be A

A randomized, placebo-controlled clinical trial on the efficacy of chiropractic therapy on premenstrual syndrome.

1.58 billion in total. The most common conditions treated were back pain and related problems and over 90% of the users of each therapy considered their treatment to be very or somewhat helpful. Adverse events are reported. Nearly one fifth of users were referred to manipulative therapy practitioners by medical practitioners.ConclusionThere is substantial use of manipulative therapies by adult Australians, especially for back-related problems. Treatments incur considerable personal expenditure. In general, patient experience is positive. Referral by medical practitioners is a major determinant of use of these manipulative therapies.

Electroacupuncture for Tension‐type Headache on Distal Acupoints Only: A Randomized, Controlled, Crossover Trial

OBJECTIVE To evaluate the efficacy of chiropractic therapy on the treatment of symptoms associated with premenstrual syndrome. DESIGN A prospective, randomized, placebo-controlled, crossover clinical trial. SETTING Multicenter private clinics. SUBJECTS Twenty-five subjects with diagnosed premenstrual syndrome (with a Moos premenstrual syndrome questionnaire plus daily symptom monitoring). INTERVENTION After randomization, 16 of the subjects received high-velocity, low-amplitude spinal manipulation plus soft tissue therapy 2 to 3 times in the week before menses for at least 3 cycles. The remaining 9 subjects received a placebo treatment with a spring-loaded adjusting instrument wound down for minimum force. After a 1-cycle washout, the 2 groups changed over. OUTCOME MEASURE Daily rating of symptom level, comparing total scores for premenstrual week with baseline for treatment and placebo phases. DATA ANALYSIS The data were analyzed with paired Student t tests and Wilcoxon signed rank tests, with the statistical significance set at P < .05. RESULTS There was a significant decrease in scores after treatment compared with baseline scores (P = .00001) and a statistically significant decrease in scores for the treatment phase compared with the placebo (P = .006). For group 1 (n = 16), there was a significant decrease in scores after treatment compared with baseline scores (P = .0001) and a statistically significant decrease in scores for the treatment phase compared with the placebo (P = .041). For group 2 (n = 9), there was a significant decrease in scores during treatment compared with the baseline (P = .01); however, there was no difference at the P = .05 level between treatment and placebo scores. CONCLUSIONS Within the limitations of the study, the results support the hypothesis that the symptoms associated with PMS can generally be reduced by chiropractic treatment consisting of adjustments and soft-tissue therapy. However, the role of a placebo effect needs further elucidation, given that the group receiving the placebo first, although improving over the baseline, showed no further improvement when they had actual treatment.

Chiropractic Observation and Analysis Study (COAST): Providing an understanding of current chiropractic practice

Objective.—To investigate the efficacy of electroacupuncture, applied to distal acupoints only, for tension‐type headache.

Effects of body position on autonomic regulation of cardiovascular function in young, healthy adults.

Objectives: COAST (Chiropractic Observation and Analysis Study) aimed to describe the clinical practices of chiropractors in Victoria, Australia.

How common are latent myofascial trigger points in the scapular positioning muscles

BackgroundAnalysis of rhythmic patterns embedded within beat-to-beat variations in heart rate (heart rate variability) is a tool used to assess the balance of cardiac autonomic nervous activity and may be predictive for prognosis of some medical conditions, such as myocardial infarction. It has also been used to evaluate the impact of manipulative therapeutics and body position on autonomic regulation of the cardiovascular system. However, few have compared cardiac autonomic activity in supine and prone positions, postures commonly assumed by patients in manual therapy. We intend to redress this deficiency.MethodsHeart rate, heart rate variability, and beat-to-beat blood pressure were measured in young, healthy non-smokers, during prone, supine, and sitting postures and with breathing paced at 0.25 Hz. Data were recorded for 5 minutes in each posture: Day 1 – prone and supine; Day 2 – prone and sitting. Paired t-tests or Wilcoxon signed-rank tests were used to evaluate posture-related differences in blood pressure, heart rate, and heart rate variability.ResultsProne versus supine: blood pressure and heart rate were significantly higher in the prone posture (p < 0.001). Prone versus sitting: blood pressure was higher and heart rate was lower in the prone posture (p < 0.05) and significant differences were found in some components of heart rate variability.ConclusionCardiac autonomic activity was not measurably different in prone and supine postures, but heart rate and blood pressure were. Although heart rate variability parameters indicated sympathetic dominance during sitting (supporting work of others), blood pressure was higher in the prone posture. These differences should be considered when autonomic regulation of cardiovascular function is studied in different postures.

Strategies to identify changes in SEMG due to muscle fatigue during cycling

Objective: To determine how commonly latent trigger points [LTrPs] occur within the scapular positioning muscles of asymptomatic adults by examining normal controls, represented by a sample of university staff and students. Methods: One hundred and fifty-four healthy subjects volunteered to undergo a physical examination for the presence of LTrPs in the trapezius, rhomboids, levator scapulae, serratus anterior, and the pectoralis minor muscles bilaterally. Results: Of the 154 subjects, 89.8 percent had at least one LTrP in the scapular positioning muscles [mean = 10.65 ± 6.8, range = 1–27]. Discussion: Consistent with clinical opinion, the current study found a high occurrence of LTrPs in the scapular positioning muscles, however, the clinical significance of their presence requires further investigation.

Power changes of EEG signals associated with muscle fatigue: the root mean square analysis of EEG bands

Detection, quantification and analysis of muscle fatigue are crucial in occupational/rehabilitation and sporting settings. Sports organizations such as the Australian Institute of Sports (AIS) currently monitor fatigue by a battery of tests including invasive techniques that require taking blood samples and/or muscle biopsies, the latter of which is highly invasive, painful, time consuming and expensive. SEMG is non-invasive monitoring of muscle activation and is an indication of localized muscle fatigue based on the observed shift of the power spectral density of the SEMG. But the success of SEMG based techniques is currently limited to isometric contraction and is not acceptable to the human movement community. This paper proposes and tests the use of spectral analysis of narrow windows of SEMG near the peak of a cyclic activity to identify the onset of muscle fatigue during cyclic activities. The results demonstrate a highly significant relationship of reduction of the median frequency with the onset of muscle fatigue. The paper also reports the validation of the SEMG study using biochemical analysis of muscle biopsy and blood tests and further verified using power output of the cycle and speed of pedalling.

Use of the measure your medical outcome profile (MYMOP2) and W-BQ12 (Well-Being) outcomes measures to evaluate chiropractic treatment: an observational study

The paper reports a research conducted to determine changes in the electrical activity of the contralateral motor cortex of the brain that drives the maximum voluntary contraction (MVC) of the right adductor pollicis muscle (APM) after fatigue. The power changes of EEG signals after muscle fatigue were computed. In twenty-five subjects, EEG signals from the left motor cortical area (C3, FC3) were recorded simultaneously with EMG signals from the right APM, before and after exercise-induced fatigue. The root mean square (RMS) of the EEG bands (alpha, beta, and gamma) was calculated to determine the power changes of the EEG signals after right APM fatigue. The mean RMS of the EEG bands were increased during MVC of the fatigued right APM compared to the RMS value during relaxation before fatigue (p<0.05). The RMS value was seen to be greatest in the beta band, and lowest in the gamma band. The observed increase in the RMS of EEG bands during MVC of the fatigued right APM suggest an increase in the EEG signal power, which could reflect an increase in energy needed by the motor cortex to perform MVC in fatigued muscles, which might give an indication of neural fatigue in the motor cortex.