Myofascial trigger points and innervation zone locations in upper trapezius muscles.

BACKGROUND: Myofascial trigger points (MTrPs) are hyperirritable spots located in taut bands of muscle fibres. Electrophysiological studies indicate that abnormal electrical activity is detectable near MTrPs. This phenomenon has been described as endplate noise and it has been purported to be associated MTrP pathophysiology. Thus, it is suggested that MTrPs will be overlap the innervation zone (IZ). The purpose of this work was to describe the location of MTrPs and the IZ in the right upper trapezius. METHODS: We screened 71 individuals and eventually enrolled 24 subjects with neck pain and active MTrPs and 24 neck pain-free subjects with latent MTrPs. Surface electromyography (sEMG) signals were detected using an electrode matrix during isometric contraction of the upper trapezius. A physiotherapist subsequently examined the subject's trapezius to confirm the presence of MTrPs and establish their location. IZ locations were identified by visual analysis of sEMG signals. IZ and MTrPs locations were described using an anatomical coordinate system (ACS), with the skin area covered by the matrix divided into four quadrants. RESULTS: No significant difference was observed between active and latent MTrPs locations (P = 0.6). Forty-five MTrPs were in the third quadrant of the ACS, and 3 were included in second quadrant. IZs were located approximately midway between the seventh cervical vertebrae and the acromial angle in a limited area in the second and third quadrants. The mean distance between MTrP and IZ was 10.4 ± 5.8 mm. CONCLUSIONS: According to the acquired results, we conclude that IZ and MTrPs are located in well-defined areas in upper trapezius muscle. Moreover, MTrPs in upper trapezius are proximally located to the IZ but not overlapped.

Pain intensity and quality of life perception in children with hypermobility syndrome.

Hypermobility syndrome (HMS) is a major source of morbidity in children. Impaired quality of life (QoL) has been observed recently in adults with HMS; however, this issue is yet to be investigated in children with this condition. This study compared pain intensity and QoL in children with HMS with healthy controls. It also examined the relationship between pain intensity and QoL in children with HMS. Following ethical approval, 29 children diagnosed with HMS and 37 healthy children aged 8-15 years participated. Informed written consent was obtained from participants and their parents/guardians. Average knee pain over the past week was examined using the Coloured Analogue Scale. QoL was measured via the Pediatric Quality of Life Inventory. Mann-Whitney U tests were performed to compare pain and QoL scores between the two groups. Spearman Rho correlation analysis was performed to examine the relationship between pain and QoL. Overall QoL scores in each domain were significantly lower in children with HMS (all p < 0.001) compared with the controls. Pain intensity was significantly higher in children with HMS compared with their healthy counterparts (p < 0.001). A strong negative correlation was observed between pain intensity and overall QoL and all the domains (r range = -0.614 to -0.717; all p < 0.001). In conclusion, the findings of the present study imply that pain and QoL assessment might form important components of clinical examination for children diagnosed with HMS. These children may benefit from appropriate treatment programmes to alleviate pain intensity and improve QoL.

Intra-rater reliability of an experienced physiotherapist in locating myofascial trigger points in upper trapezius muscle.

OBJECTIVES: Myofascial trigger points (MTrPs) are considered the principal clinical feature of myofascial pain syndrome (MPS). An MTrP consists of spot tenderness within a taut band of muscle fibers and its stimulation can produce both local and referred pain. The clinical diagnosis of MPS depends on correct history taking and a physical examination aimed at identifying the presence of MTrP. The purpose of this study was to investigate the intra-rater reliability of a palpation protocol used for locating an MTrP in the upper trapezius muscle. METHODS: Twenty-four subjects with MTrP in the upper trapezius muscle were examined by an experienced physiotherapist. During each of eight experimental sessions, subjects were examined twice in randomized order using a palpation protocol. An anatomical landmark system was defined and the MTrP location established using X and Y values. RESULTS: The intraclass correlation coefficient ICC(1,1) values were 0.62 (95% CI: 0.30-0.81) for X and 0.81 (95% CI: 0.61-0.91) for Y. The Bland-Altman plots for X and Y showed a mean of difference of 0.04 and -0.2 mm, respectively. Limits of agreement for X ranged from -26.3 to 26.2 mm and for Y from -27 to 26.4 mm. DISCUSSION: The ICC(1,1) for the observed values revealed a moderate to high correlation and the Bland-Altman analysis showed means of difference very close to zero with narrow limits of agreement. An experienced physiotherapist can reliably identify MTrP locations in upper trapezius muscle using a palpation protocol.

Reliability of surface EMG matrix in locating the innervation zone of upper trapezius muscle.

The identification of the motor unit (MU) innervation zone (IZ) using surface electromyographic (sEMG) signals detected on the skin with a linear array or a matrix of electrodes has been recently proposed in the literature. However, an analysis of the reliability of this procedure and, therefore, of the suitability of the sEMG signals for this purpose has not been reported. The purpose of this work is to describe the intra and inter-rater reliability and the suitability of surface EMG in locating the innervation zone of the upper trapezius muscle. Two operators were trained on electrode matrix positioning and sEMG signal analysis. Ten healthy subjects, instructed to perform a series of isometric contractions of the upper trapezius muscle participated in the study. The two operators collected sEMG signals and then independently estimated the IZ location through visual analysis. Results showed an almost perfect agreement for intra-rater and inter-rater reliability. The constancy of IZ location could be affected by the factors reflecting the population of active MUs and their IZs, including: the contraction intensity, the acquisition period analyzed, the contraction repetition. In almost all cases the IZ location shift due to these factors did not exceed 4mm. Results generalization to other muscles should be made with caution.

Gait kinematics and passive knee joint range of motion in children with hypermobility syndrome.

Hypermobility syndrome (HMS) is characterised by generalised joint laxity and musculoskeletal complaints. Gait abnormalities have been reported in children with HMS but have not been empirically investigated. The extent of passive knee joint range of motion (ROM) has also not been well reported in children with HMS. This study evaluated gait kinematics and passive knee joint ROM in children diagnosed with HMS and healthy controls. Thirty-seven healthy children (mean age±SD=11.5±2.6 years) and 29 children with HMS (mean age±SD=11.9±1.8 years) participated. Sagittal knee motion and gait speed were evaluated using a VICON 3D motion analysis system. Passive knee ROM was measured with a manual goniometer. Independent t-tests compared the values of sagittal knee motion and gait speed between the two groups. Mann-Whitney U tests compared passive knee ROM between groups. Passive ROM (extension and flexion) was significantly higher (both p<0.001) in children with HMS than the healthy controls. Peak knee flexion (during loading response and swing phase) during walking was significantly lower (both p<0.001) in children with HMS. Knee extension in mid stance during walking was significantly increased (p<0.001) in children with HMS. However, gait speed was not statistically (p=0.496) different between the two groups. Children with HMS had higher passive knee ROM than healthy children and also demonstrated abnormal knee motion during gait. Gait re-education and joint stability exercise programmes may be of value to children with HMS.

Repeatability of joint proprioception and muscle torque assessment in healthy children and in children diagnosed with hypermobility syndrome.

BACKGROUND: Impairment of joint proprioception in patients with hypermobility syndrome (HMS) has been well documented. Both joint proprioception and muscle torque are commonly assessed in patients with musculoskeletal complaints. It is unknown, however, if these measures change significantly on repeated application in healthy children and in children with HMS. AIM: To investigate the between-days repeatability of joint proprioception and muscle torque in these groups. METHODS: Twenty children (10 healthy and 10 with HMS), aged eight to 15 years, were assessed on two separate occasions (one week apart) for joint kinaesthesia (JK), joint position sense (JPS), and the extensor and knee flexor muscle torque of the knee. JK was measured using threshold to detection of passive movement. JPS was measured using the absolute angular error (AAE; the absolute difference between the target and perceived angles). Knee extensor and flexor muscle torque was normalized to body weight. RESULTS: Intra-class correlation coefficients (ICC) for JK, extensor and flexor muscle torque were excellent in both groups (range 0.83 to 0.98). However, ICC values for JPS tests were poor to moderate in the two groups (range 0.18 to 0.56). 95% limits of agreement (LOA) were narrow in both cohorts for JK and muscle torque (indicating low systematic error) but wide for the JPS tests. 95% LOA also demonstrated that the measuring instruments used in this study had low between-days systematic error. CONCLUSIONS: Based on ICC and 95% LOA, the repeatability of JK and muscle torque measurements was excellent in both healthy children and those with HMS. The JPS test can only be assessed with poor to moderate repeatability. The use of the JPS test in these children should be undertaken with caution.

Effects of taping on pain and function in patellofemoral pain syndrome: a randomized controlled trial.

STUDY DESIGN: A randomized controlled trial. OBJECTIVES: To investigate the effectiveness of daily patella taping and exercise on pain and function in individuals with patellofemoral pain syndrome. BACKGROUND: Patella taping and muscle-strengthening programs are commonly used to treat patellofemoral pain syndrome. There is, however, little evidence for the effectiveness of these approaches. METHODS AND MEASURES: Twenty-four men and 6 women aged 17 to 25 years (mean +/- SD, 18.7 +/- 1.2 years) participated in the study. Subjects were randomly and exclusively assigned to 1 of 3 treatment groups: patella taping combined with a standardized exercise program, placebo patella taping and exercise program, or exercise program alone (n = 10 in each group). Taping was applied and exercises performed on a daily basis for 4 weeks. Outcome measures were visual analog scales for pain and the functional index questionnaire, recorded at weekly intervals by a therapist who was blinded to group allocation. RESULTS: Separate mixed-model ANOVAs, with repeated measures on time, indicated statistically significant improvements in pain and function over time for all groups (P<.01) and also significant differences between groups for all measures (P<.01). Separate independent samples t tests showed that the group receiving taping and exercises had better pain and function scores following treatment than the placebo taping-and-exercise group and the exercise-alone group. There were no significant differences between the placebo taping-and-exercise group and exercise-alone group at any time point. CONCLUSIONS: These findings indicate that over a period of 4 weeks a combination of daily patella taping and exercises was successful in improving pain and function in individuals with patellofemoral pain syndrome. The combination of patella taping and exercise was superior to the use of exercise alone.