Refining and adapting the measurement properties of evidence-based practice measures for physiotherapy students.

OBJECTIVE: There is a lack of reliable and valid evidence-based practice (EBP) measures for physiotherapy students. This study validated EBP-student (EBP-S) measures for physiotherapy students. METHODS: EBP measures developed from previous research were cross-culturally validated for use by physiotherapy students. The adapted EBP-S consisted of six measures: use of EBP, EBP activities, EBP knowledge, self-efficacy for EBP, attitudes towards EBP, and perceptions of the teaching and assessment of EBP in the curriculum. The final version was completed by physiotherapy students (n = 335). The psychometric properties for each EBP-S measure were estimated, including construct validity using Rasch model, internal consistency reliability using person separation index (PSI), test-retest reliability using intraclass correlation coefficient (ICC), and differential item functioning (DIF). RESULTS: Two formative measures (use of EBP and EBP activities) were only linguistically modified for use with students. A Rasch model was applied to the other four reflective measures. For knowledge, 55% (6/11) items fit the Rasch model with chi-square fit statistic (χ2) = 34.46, p = 0.08; PSI = 0.85. For self-efficacy, 89% (8/9) items fit the Rasch model with χ2 = 25.11, p = 0.80; PSI = 0.89. For attitudes, 62% (8/13) items fit the Rasch model with χ2 = 61.49, p = 0.00; PSI = 0.71. For perception of the teaching and assessment of EBP in the curriculum, 62% (8/13) items fit the Rasch model with χ2 = 80.99, p = 0.45; PSI = 0.92. perception of the teaching and assessment of EBP in the curriculum showed DIF in three items. The ICCs ranged between 0.80 and 0.98. CONCLUSIONS: The EBP-S measures were validated for physiotherapy students, including the testing of psychometric properties, which were not tested in the original studies. Further refinements should be considered for the use of the EBP-S with other groups of students or if changes are applied to the current curriculum.

Reactive postural adjustment in response to predictable and unpredictable perturbations in healthy adults: A comparison between swayback, hyperlordotic and erect postures.

BACKGROUND: Promoting an erect posture in standing has been advocated to offer superior protection to the spine when compared to hyperlordotic and swayback postures. RESEARCH QUESTION: Do postural adjustments towards external perturbation differ between erect, hyperlordotic and swayback postures? If so, which posture offers better protection to lumbar spine? METHODS: Forty-four healthy adults received top-down perturbations under unpredictable (without visual-and-auditory input) and predictable (with visual-and-auditory input) conditions in three simulated postures: erect, hyperlordotic, and swayback. Postural adjustments namely the centre of pressure parameters, joint angle onsets, and neuromuscular responses measured by muscle onsets and co-contraction between muscle pairs upon the perturbation were compared using the two-way repeated measures ANOVA. Post-hoc analysis with Bonferroni correction was conducted to identify the between-posture differences for the respective postural adjustment parameters. RESULTS: Path length, ellipse area and average velocity of centre of pressure were significantly greater under unpredictable condition as compared to predictable condition (p < 0.001). Significant between-posture difference was detected in centre of pressure path length (p < 0.035), pelvic tilt onset (p < 0.038) and all muscle co-contraction indexes (p < 0.001). Post-hoc analysis revealed significantly smaller centre of pressure path length in erect posture as compared to hyperlordotic and swayback postures (p < 0.01) under unpredictable conditions. Significantly greater co-contraction indexes of lumbar multifidus and erector spinae, and internal oblique and lumbar multifidus were found in hyperlordotic as compared to erect and swayback postures (p < 0.05). SIGNIFICANCE: Compared to erect posture, adoption of hyperlordotic and swayback postures altered the contributions of the active and passive subsystems of the spine that regulates postural control upon external perturbations. Such differences in neuromuscular control may lessen the capacity of the human spine to withstand loading and shear forces. Prospective studies are required to validate if habitually adopted hyperlordotic and swayback postures contribute to an earlier/ higher prevalence of spinal dysfunctions.

Effect of chest wall mobilization on respiratory muscle function in patients with severe chronic obstructive pulmonary disease (COPD): A randomized controlled trial.

BACKGROUND: Clinical trials have demonstrated positive correlation between pulmonary function and chest wall expansion in COPD. Decrease in chest wall expansion in patients with COPD compromises rib cage mobility and functional length of respiratory muscles that ultimately jeopardize the efficacy and function of respiratory system. METHOD: Thirty male adults (mean age: 74.97 ± 6.29) suffered with severe COPD were randomly allocated to either experimental group (chest wall mobilizations) or control group. Both groups received standardized education and walking exercise (twice/week) for 6 weeks. Patients in experimental group received additional chest wall mobilizations that include stretching and joints mobilization. Pulmonary function, respiratory muscle strength, thoracic excursion, cervical and thoracic range of movement were evaluated at baseline, post-program and at 3-month follow-up. RESULTS: There were significantly greater improvements in respiratory muscle strength, thoracic excursion and thoracic range of movement (p < 0.01) except thoracic flexion. Lower thoracic excursion is strongly associated with increase in maximum inspiratory pressure (ß = 13.64, p < 0.001) and maximum expiratory pressure (ß = 16.23, p < 0.001). Thoracic range of movement especially extension (p < 0.001) and bilateral rotation (p < 0.01) exhibit a strong relationship with increase in lower thoracic excursion (adjusted R2 = 0.876) as shown in multiple regression analysis. CONCLUSION: Additional chest wall mobilization in the rehabilitation of patients with COPD is likely to enhance thoracic extension and rotation which increase lower thoracic excursion. This significant improvement in chest expansion capacity allows respiratory muscles to work at an optimal functional length which result in greater respiratory muscle strength in patients with severe COPD.

Evaluation of a Restoration Algorithm Applied to Clipped Tibial Acceleration Signals.

Wireless accelerometers with various operating ranges have been used to measure tibial acceleration. Accelerometers with a low operating range output distorted signals and have been found to result in inaccurate measurements of peaks. A restoration algorithm using spline interpolation has been proposed to restore the distorted signal. This algorithm has been validated for axial peaks within the range of 15.0-15.9 g. However, the accuracy of peaks of higher magnitude and the resultant peaks have not been reported. The purpose of the present study is to evaluate the measurement agreement of the restored peaks using a low-range accelerometer (±16 g) against peaks sampled using a high-range accelerometer (±200 g). The measurement agreement of both the axial and resultant peaks were examined. In total, 24 runners were equipped with 2 tri-axial accelerometers at their tibia and completed an outdoor running assessment. The accelerometer with an operating range of ±200 g was used as reference. The results of this study showed an average difference of -1.40 ± 4.52 g and -1.23 ± 5.48 g for axial and resultant peaks. Based on our findings, the restoration algorithm could skew data and potentially lead to incorrect conclusions if used without caution.

Excessive use of electronic devices among children and adolescents is associated with musculoskeletal symptoms, visual symptoms, psychosocial health, and quality of life: a cross-sectional study.

Objective: Electronic devices have become an indispensable part of our daily lives. The frequency and duration of device use in children and adolescents have increased drastically over the years and the study of its negative musculoskeletal, visual and psychosocial health impacts is necessary. Materials and methods: This cross-sectional study aimed to evaluate the associations between electronic device use and the prevalence and severity of musculoskeletal symptoms, visual symptoms, psychosocial health, and quality of life in children and adolescents studying at primary and secondary schools. Data were collected through confidential online and paper-and-pencil questionnaires. Primary 4-5 and Secondary 1-4 students were recruited from 3 schools in Hong Kong. Demographics, frequency and duration of electronic device use, frequencies of musculoskeletal symptoms, visual symptoms, psychosocial health, and quality of life outcomes were measured. Results: 1,058 children and adolescents aged 9-17 years participated. Sixty-one percent and 78% of all students spent more than 2 h per day using electronic devices during school days and weekend/holidays, respectively. Extended electronic device use was associated with increased prevalence and severity of musculoskeletal symptoms (ρ's = 0.28-0.33, P's < 0.001), visual symptoms (ρ's = 0.33-0.35, P's < 0.001), and poorer device use-related psychosocial health (ρ's = 0.38-0.47, P's < 0.001). Secondary school students reported greater device use and severity of symptoms than primary school students. Conclusion: Excessive electronic device use was associated with increased prevalence and severity of physical and psychosocial symptoms, and such use is more prevalent in adolescents when compared to the children. The findings have important health implications for children and adolescents, suggesting that early intervention is needed to reduce the risk of developing device use-related disorders.

Effect of muscle fatigue of the thoracic erector spinae on neuromuscular control when performing the upper extremity functional tasks in people with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) disrupts spinal alignment and increases the intrinsic demand for active stabilization to maintain postural stability. Understanding the paraspinal muscle fatigability and its effects on spinal alignment and kinematics informs the importance of paraspinal muscle endurance for postural stability. This study aims to investigate the effects of fatigue of thoracic erector spinae on the spinal muscle activity and spinal kinematics in individuals with scoliosis. Spinal muscle activity, posture and mobility measured by electromyography and surface tomography were compared between 15 participants with scoliosis and 15 age- and gender-matched healthy controls during unilateral shoulder flexion and abduction with and without holding a 2-kg weight and performed before and after a fatigue task (prone isometric chest raise). No between-groups difference was found for the spinal extensor endurance. Erector spinae activity at the convex side of AIS group was significantly higher than that at their concave side and than that of healthy controls during shoulder elevations, regardless of the fatigue status. Significant decreases in translational and rotational mobility were found at convex side of AIS group during weighted abduction tasks after fatigue. In contrast, a significant increase in rotational mobility was demonstrated at convex side of AIS participants during weighted flexion tasks after fatigue. Our results revealed a comparable level of spinal extensor endurance between individuals with or without AIS. The increase in muscle activation post-fatigue provides no additional active postural stability but may increase the risk of back pain over the convex side in individuals with scoliosis. Findings highlight imbalances in muscles and the potential implications in optimising neuromuscular activation and endurance capacity in the rehabilitation for AIS patients. Future research is needed to investigate if endurance training of the convex-sided back extensors could optimize the impaired neuromuscular control in the AIS patients.

Severity of slouched posture during smartphone use is associated with the musculoskeletal discomfort, daily usage, and school year among adolescents.

Real-time measurement of the craniovertebral, thoracic kyphosis, and lumbar lordosis angles during natural and smartphone usage postures in sitting were analysed in a cohort of 560 adolescents using independent t-tests and Spearman's correlations between their reported musculoskeletal symptoms, daily device use and school year. Students with musculoskeletal symptoms (mean difference: 4.1-9.4°, p < .001) and in secondary schools (mean difference: 13.6-29.4°, p < .001) had a greater forward-head posture quantified by craniovertebral angle in both postures. Loss of lumbar lordosis was found in students spending ≥2 h/day on electronic devices (mean difference: 3.2°, p = .029) and those with musculoskeletal symptoms (mean difference: 5.4°, p = .001). Secondary school students exhibited a greater thoracic kyphosis when using smartphones (mean difference: 3.3°, p = .003). Findings suggest the urgent need for early and proactive intervention targeted to minimise the risk of developing musculoskeletal disorders related to intense device use for young adolescents.Practitioner Summary: Adolescents: (1) in higher school year had increased forward-head posture (FHP) and thoracic kyphosis; (2) with musculoskeletal symptoms had increased FHP and loss of lumbar lordosis, and; (3) with extended device use had a loss of lumbar lordosis. Early intervention targeting young adolescents promoting optimal posture and habit of device use is warranted.

Using cervical movement velocity to assist the prediction of pain and functional recovery for people with chronic mechanical neck pain.

BACKGROUND: Impaired cervical kinematics particularly the movement velocity had been consistently found in people with neck pain. The recovery and potential of cervical movement velocity in assisting the prediction of recovery in individuals with chronic neck pain remained unknown. This study investigated the application of cervical movement velocity to predict the outcomes of pain intensity and functional disability for a cohort of participants with chronic mechanical pain after completion of a 12-week intervention program. METHODS: Cervical movement velocity when performing neck motions in the anatomical planes, pain intensity and functional disability score were assessed before and after the physiotherapy program. Correlations between kinematic and clinical outcomes, and validity of applying the peak velocity values of the cervical spine measured at baseline for prediction of recovery of pain and function after the physiotherapy program were examined (n = 68). FINDINGS: Significant improvements were found in the peak values of cervical velocity in all movement planes, pain intensity and functional disability score at post-program reassessment (p < 0.001). Significant negative correlations between peak values of cervical movement velocity and pain intensity (for specific directions, r = -0.163 to -0.191), and functional disability were found (for all directions, r = -0.158 to -0.282). Area under the Receiver Operating Characteristics curve was >0.6 for cervical extension, flexion and right rotation velocity for predicting functional recovery post-program. INTERPRETATION: These findings suggest that cervical velocity of selected planes measured at baseline may inform the prediction of recovery of functional disability but not pain intensity in people with chronic mechanical neck pain.

Recovery of the lumbopelvic movement and muscle recruitment patterns using motor control exercise program in people with chronic nonspecific low back pain: A prospective study.

This study aims to investigate the dysfunction and recovery of the lumbopelvic movement and motor control of people with chronic nonspecific low back pain after a structured rehabilitation which emphasizes on re-education and training of movement and motor control. The lumbopelvic movement and motor control pattern of 30 adults (15 with chronic low back pain, 15 healthy controls) were assessed using 3D motion and electromyographic analysis during the repeated forward bending test, in additional to the clinical outcome measures. Regional kinematics and muscle recruitment pattern of the symptomatic group was analysed before and after the 6-week rehabilitation, and compared to healthy controls. Significant improvement in back pain, functional capacity and self-efficacy of the symptomatic group was found after the rehabilitation. Patients with chronic nonspecific low back pain were capable to recover to a comparable level of the healthy controls in terms of their lumbopelvic movement and motor control pattern upon completion of a 6-week rehabilitation program, despite their dysfunction displayed at baseline. Phase specific motor control reorganization in which more profound and positive changes shown during the flexion phase. Our findings indicate that the recovery of the movement and motor control pattern in patients with chronic low back pain achieved to a comparable level of the healthy able-bodies. The improvement of both the physical outcome measures suggest that specific rehabilitation program which emphasizes on optimizing motor control during movements would help promoting the functional recovery of this specific low back pain subgroup.

A field study on spinal postures and postural variations during smartphone use among university students.

This field study compared the real-time spinal movements and postural variations during smartphone-use versus non-use in university students. Ten males and eight females (mean age of 21.5 ± 2.6 years) participated, with similar daily phone use time between the two sexes. Five inertial motion sensors were attached to the cervical, thoracic and lumbar spinal regions, and kinematics was recorded for 3 h while participants went about their usual academic activities within the university campus. Significantly greater degrees of cervical and upper thoracic flexion were adopted during phone use versus non-use time (p < 0.01). There were also significantly greater frequency of postural variations (zero crossing per min) in all spinal regions in the sagittal plane (all p < 0.05), and in some of the movements in transverse and frontal planes comparing phone use vs non-use. The postural variables also showed some significant correlations with self-reported pre-existing neck and upper back pain scores.

Effects of Ergomotor Intervention on Improving Occupational Health in Workers with Work-Related Neck-Shoulder Pain.

(1) Background: Work-related neck and shoulder pain (WRNSP) are common problems, and past occupational research has focused on ergonomic interventions such as adjusting workstations while physiotherapists have traditionally focused on teaching exercises to improve posture and movement control in the clinical setting. The current study aimed to integrate these two approaches and evaluate the immediate and long-term effects of such interventions on occupational exposure outcomes. (2) Methods: A total of 101 patients diagnosed with WRNSP were randomized into 2 groups: Control (CO) group (n = 50) and ergomotor (EM) group (n = 51). Participants in the control group had 12 weeks of usual care (conventional physiotherapy) while participants in the EM group received an integrated program with tailor-made motor control training and ergonomic advice for 12 weeks. (3) Results: Both groups achieved significant improvement in pain and functional outcomes at post-intervention. The EM group also reported significantly improved scores in terms of perceived exertion in the job-related physical demands (JRPD) and the short form workstyle questionnaires compared to the control group. (4) Conclusions: The results suggest that ergomotor intervention may be more effective in producing favorable occupational health outcomes compared to conventional physiotherapy.

Comparing the effectiveness of integrating ergonomics and motor control to conventional treatment for pain and functional recovery of work-related neck-shoulder pain: A randomized trial.

BACKGROUND: Work-related neck and shoulder pain (WRNSP) is highly prevalent among patients who seek physiotherapy treatment. Clinicians may tend to focus on teaching home exercises and provide general advice about workplace improvement. The present study investigates the short- and long-term impact of an intervention approach that emphasizes on integrating the motor control re-education with ergonomic advice. METHODS: Participants diagnosed with WRNSP (n = 101) were randomly assigned into two groups in this randomized controlled trial. The Ergo-motor Group (EM, n = 51) received an integrated intervention with ergonomic advice/modifications and motor control training individualized for each participant based on their specific work demands. Control Group (CO, n = 50) received treatment for pain relief and general exercises of their necks at a designated physiotherapy clinic. Neck pain intensity and functional outcome measures were assessed before, immediately and 1-year after the 12-week intervention programmes. Global Rating of Change Score was used to evaluate the perceived recovery at 1-year follow-up. RESULTS: Both groups reported significant reductions in pain and functional disability scores at post-intervention (EM, n = 44; CO, n = 42) and 1-year follow-up (EM, n = 40; CO, n = 38); however, no significant between-group differences were found (p > 0.05). Significantly higher rating in global recovery score was reported in EM group at 1-year follow-up (p < 0.05). CONCLUSIONS: Intervention integrating ergonomic advice/modification with motor control exercise was found to be equally effective as pain relief and general exercise for pain and functional recovery. However, at 1-year follow-up, such integrated approach resulted in significantly better global recovery perceived by people with WRNSP. SIGNIFICANCE: Integrating ergonomic intervention and motor control training achieved similar reduction in pain and functional outcomes compared to conventional physiotherapy at post-intervention and at 1-year follow-up, for patients with moderate level of work-related neck-shoulder pain and mild degree of functional disability. The Ergo-motor Group reported significantly better perceived overall recovery at 1-year follow-up.

Abdominal muscle recruitment and its effect on the activity level of the hip and posterior thigh muscles during therapeutic exercises of the hip joint.

Abdominal exercise has been advocated to improve the protection of the spine and neuromuscular efficiency of the limb movements. The purpose of this study was to examine the effect of enhanced contraction of internal oblique and transversus abdominis (IO/TrA) on the activity level of the hip and posterior thigh muscles during therapeutic hip exercises. Twenty healthy females were required to perform eight hip exercises under two conditions, natural versus enhanced IO/TrA contraction conditions. Muscle activity of gluteus maximus, gluteus medius, tensor fasciae latae and biceps femoris of the exercising leg was measured by surface electromyography during hip exercises, and expressed in percentage normalized to the maximal voluntary isometric contraction (%MVIC). The activity levels of the gluteal and posterior thigh muscles recorded under natural and enhanced IO/TrA conditions were compared. IO/TrA was found to have activated at the range of 2.7%-16.1% and 6.3%-24.1% of MVIC when hip exercises were executed under natural and enhanced conditions respectively. Enhanced IO/TrA contraction resulted in significantly greater activity in gluteus maximus, gluteus medius and bicep femoris at various phases of hip extension and clam exercises, single leg sit-to-stand and pelvic drop exercise (increased by 1.7-7.2% of MVIC). These findings indicate the presence of coactivation of the abdominal and hip muscles when performing the free active hip exercises. Further studies are recommended to investigate the efficacy of this muscle coactivation in improving the clinical outcome of therapeutic hip exercises.

Association of electromyographic activation patterns with pain and functional disability in people with chronic neck pain.

PURPOSE: This study examined the activation patterns of the cervical and thoracic muscles in people with and without chronic neck pain during functional activities and their associations with pain intensity and functional disability. METHODS: Thirty-four adults with chronic neck pain and 34 asymptomatic adults were recruited. They were requested to perform active cervical movements and an upper limb lifting task. Electromyographic activation patterns (EMG) of bilateral upper trapezius, cervical erector spinae, sternocleidomastoid, and thoracic erector spinae were recorded during these tasks. Correlation and multiple regression analysis were used to examine the associations between EMG variables and severity of pain and functional disability. RESULTS: When performing the cervical movements, the neck pain group displayed lower EMG activity levels, especially in the cervical and thoracic extensors. In addition, significantly prolonged activation was observed in seven of the ten muscles during the upper limb lifting task. The changes in EMG amplitude and activation duration were found to be significantly correlated with severity of pain (R2 = 0.716) and functional disability (R2 = 0.623). CONCLUSIONS: Significant differences in the activation patterns of multiple cervical and thoracic muscles were found in individuals with neck pain compared with those without neck pain. These were significantly associated with their degree of pain and functional limitation. The findings of this study highlight the importance of assessing and optimising the neuromuscular activation of these muscles in the rehabilitation of those suffering from chronic neck pain.

Changes in Lumbopelvic Movement and Muscle Recruitment Associated with Prolonged Deep Squatting: A Pilot Study.

This study examined the changes in spinal kinematics and muscle recruitment of the lumbopelvic region associated with prolonged squatting. Eight subjects with chronic nonspecific low back pain (LBP) and eight asymptomatic subjects (AS) performed squat-to-stand and reverse movements, before and immediately after 15 min deep-squatting. Within-group and between-group differences in lumbopelvic kinematics and electromyographic activity acquired in lumbar erector spinae (ES), gluteus maximus (GM), and vastus lateralis (VL) were analyzed. During squat-to-stand after squatting, the LBP group showed slower then faster lumbar movement in the second and third quartiles, respectively. In the second quartile, the AS group moved with a significantly greater lumbar angle. However, significantly greater bilateral GM activity (+4⁻4.5%) was found in the LBP group only. A more profound decrease in bilateral ES activity (-10%) was also shown in the LBP group, yet this was nonsignificant compared to the AS group (-4%). In the third quartile, only the LBP group moved with a significantly greater lumbar angle, together with a significant increase in bilateral ES (+6⁻8%) and GM muscle (+2⁻3%) activity. The findings of the altered pattern of joint kinematics and recruitment of the key lumbopelvic muscles displayed in the LBP group inform on the possible mechanisms that may contribute to the increased risk of developing lumbar dysfunctions for people who work in prolonged squatting postures.

Effects of combining ergonomic interventions and motor control exercises on muscle activity and kinematics in people with work-related neck-shoulder pain.

PURPOSE: This study compared the effects of "Ergomotor" intervention and conventional physiotherapy, on influencing the motor control in the neck-shoulder region in people with work-related neck-shoulder pain (WRNSP). METHODS: 101 patients (age range 20-54 years) diagnosed with chronic WRNSP were randomized into control (CO) group (n = 50) and Ergomotor (EM) group (n = 51). Each group received a 12-week intervention. Participants in CO group received treatment for pain relief and general exercises. EM group received individualized motor control training and advice of ergonomic modifications at their workplaces. RESULTS: At post-intervention, EM group showed significant reduction of bilateral upper trapezius muscle activity during active neck movements (left: 40-35%, right: 35-27%) and functional tasks such as lifting a weight forward-backward (left: 31-21%, right: 22-14%) and upward-downward (left: 26-23%, right: 20-13%). Cervical erector spinae also showed significant decrease in muscle activity during some phases of the functional tasks (left: 13-6%, right: 10-2%). In contrast, CO group did not show such changes in muscle activity at post-intervention. EM group also showed significant increase in movement velocity and acceleration during active neck movements in all directions (from 18 to 31%), while CO group only showed significant increase in movement velocity in some directions. Both groups reported significant but similar reduction in pain scores, at post-intervention and 1-year follow-up. CONCLUSIONS: The present results provided some evidence to support the positive and sustainable benefits of integrating motor control training into the workplace postures and motions.

The effects of bending speed on the lumbo-pelvic kinematics and movement pattern during forward bending in people with and without low back pain.

BACKGROUND: Impaired lumbo-pelvic movement in people with low back pain during bending task has been reported previously. However, the regional mobility and the pattern of the lumbo-pelvic movement were found to vary across studies. The inconsistency of the findings may partly be related to variations in the speed at which the task was executed. This study examined the effects of bending speeds on the kinematics and the coordination lumbo-pelvic movement during forward bending, and to compare the performance of individuals with and without low back pain. METHODS: The angular displacement, velocity and acceleration of the lumbo-pelvic movement during the repeated forward bending executed at five selected speeds were acquired using the three dimensional motion tracking system in seventeen males with low back pain and eighteen males who were asymptomatic. The regional kinematics and the degree of coordination of the lumbo-pelvic movement during bending was compared and analysed between two groups. RESULTS: Significantly compromised performance in velocity and acceleration of the lumbar spine and hip joint during bending task at various speed levels was shown in back pain group (p < 0.01). Both groups displayed a high degree of coordination of the lumbo-pelvic displacement during forward bending executed across the five levels of speed examined. Significant between-group difference was revealed in the coordination of the lumbo-pelvic velocity and acceleration (p < 0.01). Asymptomatic group moved with a progressively higher degree of lumbo-pelvic coordination for velocity and acceleration while the back pain group adopted a uniform lumbo-pelvic pattern across all the speed levels examined. CONCLUSIONS: The present findings show that bending speed imposes different levels of demand on the kinematics and pattern of the lumbo-pelvic movement. The ability to regulate the lumbo-pelvic movement pattern during the bending task that executed at various speed levels was shown only in pain-free individuals but not in those with low back pain. Individuals with low back pain moved with a stereotyped strategy at their lumbar spine and hip joints. This specific aberrant lumbo-pelvic movement pattern may have a crucial role in the maintenance of the chronicity in back pain.

Relationship between neck acceleration and muscle activation in people with chronic neck pain: Implications for functional disability.

BACKGROUND: Previous study has found that people with chronic neck pain moved with a consistently compromised acceleration/deceleration at their cervical and thoracic spines. This study examined the strength of the association between the electromyographic activities and the acceleration/deceleration of the cervical and thoracic spine, and its correlation with the functional disabilities in individuals with neck pain. METHODS: Time history of the cervical and thoracic acceleration/deceleration and EMG activity was acquired in thirty-four subjects with chronic neck pain and thirty-four age- and gender-matched asymptomatic subjects during active neck movements. The strength of the association between the electromyographic activity of spinal muscles and the cervical and thoracic acceleration/deceleration was determined using cross-correlation method. Relationship between the strength of this association and the severity of the functional disabilities in neck pain group was examined using correlation analysis. FINDINGS: The strength of the association between cervical and thoracic acceleration/deceleration and electromyographic activities was significantly lower in neck pain group. Significant negative correlations were found between the functional disability level and the strength of this defined association in the symptomatic group. INTERPRETATION: The compromised capability of the spinal muscles to produce acceleration/deceleration in the neck pain group may imply an impaired electromechanical coupling of these spinal muscles when performing neck movements. Significant negative correlation of the degree of functional disabilities suggests that the present approach can be used as an objective and specific evaluation of the dynamic performance of the spinal muscles and its relationship with the functional disabilities in neck pain subjects.

Altered spinal kinematics and muscle recruitment pattern of the cervical and thoracic spine in people with chronic neck pain during functional task.

Knowledge on the spinal kinematics and muscle activation of the cervical and thoracic spine during functional task would add to our understanding of the performance and interplay of these spinal regions during dynamic condition. The purpose of this study was to examine the influence of chronic neck pain on the three-dimensional kinematics and muscle recruitment pattern of the cervical and thoracic spine during an overhead reaching task involving a light weight transfer by the upper limb. Synchronized measurements of the three-dimensional spinal kinematics and electromyographic activities of cervical and thoracic spine were acquired in thirty individuals with chronic neck pain and thirty age- and gender-matched asymptomatic controls. Neck pain group showed a significantly decreased cervical velocity and acceleration while performing the task. They also displayed with a predominantly prolonged coactivation of cervical and thoracic muscles throughout the task cycle. The current findings highlighted the importance to examine differential kinematic variables of the spine which are associated with changes in the muscle recruitment in people with chronic neck pain. The results also provide an insight to the appropriate clinical intervention to promote the recovery of the functional disability commonly reported in patients with neck pain disorders.

Movement coordination and differential kinematics of the cervical and thoracic spines in people with chronic neck pain.

BACKGROUND: Research on the kinematics and inter-regional coordination of movements between the cervical and thoracic spines in motion adds to our understanding of the performance and interplay of these spinal regions. The purpose of this study was to examine the effects of chronic neck pain on the three-dimensional kinematics and coordination of the cervical and thoracic spines during active movements of the neck. METHODS: Three-dimensional spinal kinematics and movement coordination between the cervical, upper thoracic, and lower thoracic spines were examined by electromagnetic motion sensors in thirty-four individuals with chronic neck pain and thirty-four age- and gender-matched asymptomatic subjects. All subjects performed a set of free active neck movements in three anatomical planes in sitting position and at their own pace. Spinal kinematic variables (angular displacement, velocity, and acceleration) of the three defined regions, and movement coordination between regions were determined and compared between the two groups. FINDINGS: Subjects with chronic neck pain exhibited significantly decreased cervical angular velocity and acceleration of neck movement. Cross-correlation analysis revealed consistently lower degrees of coordination between the cervical and upper thoracic spines in the neck pain group. The loss of coordination was most apparent in angular velocity and acceleration of the spine. INTERPRETATION: Assessment of the range of motion of the neck is not sufficient to reveal movement dysfunctions in chronic neck pain subjects. Evaluation of angular velocity and acceleration and movement coordination should be included to help develop clinical intervention strategies to promote restoration of differential kinematics and movement coordination.