Search

Exergaming, or technology-driven physical exercise, has gained popularity in recent years. Its applications include physical education, health promotion, and rehabilitation. Although studies have obtained promising results regarding the positive effects of exergaming, the outcomes of exergaming for different populations remain undetermined. Inconsistencies in the literature on this topic have multiple potential explanations, including the content and demand of the exergames and the capability of the exergamer. A model with a sound theoretical framework is required to facilitate matching between games and gamers. This article proposes a relational model based on a matrix of Bloom's taxonomy of learning domains and the performance components of exergames. Appropriate matching of the physical demands of an exergame and the ability of the exergamer would enhance the effective usage of exergaming for individuals with various needs. This theory-based exergame model is developed to promote the general development, physical status, and psychosocial well-being of students, older adults, and individuals with rehabilitation needs. This model may provide a resource for future research on the application, effectiveness, and design of exergaming., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Chow and Mann.)

Distance running related injuries are common, and many ailments have been associated with faulty posture. Conventional measurement of running kinematics requires sophisticated motion capture system in laboratory. In this study, we developed a wearable solution to accurately predict lower limb running kinematics using a single inertial measurement unit placed on the left lower leg. The running data collected from participants was used to train a model using long short-term memory (LSTM) neural networks with an inter-subject approach that predicted lower limb kinematics with an average accuracy of 80.2%, 85.8%, and 69.4% for sagittal hip, knee and ankle joint angles respectively for the ipsilateral limb. A comparable accuracy range was observed for the contralateral limb. The average RMSE (root mean squared error) of sagittal hip, knee and ankle were 8.76°, 13.13°, and 9.67° respectively for the ipsilateral limb. Analysis of contralateral limb kinematics was performed. The model established in this study can be used as a monitoring device to track essential running kinematics in natural running environments. Besides, the wearable solution can be an integral part of a real-time gait retraining biofeedback system for injury prevention and rehabilitation.

Student well-being and its relationships with academic achievement in China have not been well-investigated. This study aimed at investigating student well-being and the trade-off of the well-being and academic achievement with a sample of 1,353 Chinese high-school students from four cities in China during coronavirus disease 2019 (COVID-19) pandemic period. The six dimensions of well-being (academic, psychological, self, physical, social, and spiritual) were utilised to test the relationships with three subjects including Mathematics, English, and Chinese using a quantitative analysis. In this study, the relationships between six dimensions of well-being and three academic subject achievements were tested in one statistical model. Results showed that spiritual well-being was ranked the highest, followed by psychological, physical, self, and social well-being. Students gave the lowest ranking to academic well-being. The two significant paths identified were between spiritual well-being and two subjects, namely, Chinese and Mathematics. It is interesting to note that the other five dimensions of well-being were significantly associated with any subjects and English was not significantly related to any dimensions of well-being in this study. Our findings suggested that policymakers and other stakeholders should avoid an "all or nothing" mindset on practice when considering well-being as a multidimensional construct., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ling, Chen, Chow, Xu and Li.)

Background: Active exercise is the only proven effective intervention for knee osteoarthritis (OA). The addition of manual therapy has shown to improve outcome of exercises. Passive mobilization with submaximal bilateral passive ankle dorsiflexion was examined in a double-blinded randomized controlled clinical trial. A passive ankle dorsiflexion apparatus was used to standardize the frequency, range of motion, and duration parameters., Objectives: The purpose of the study was to determine whether a simple standardised mobilization technique could be incorporated as a safe and unsupervised conservative treatment for knee OA., Methods: In total, 73 participants were randomly assigned to the experimental (n= 37) or control group (n= 36). All participants performed active exercises and received six sessions of 10-minute dorsiflexion intervention, either real or sham, for two weeks. Pre- and post-experimental assessments for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and range of motion of the knee were conducted., Results: Results were analyzed using two-way repeated measures analysis of variance and Independent-Samples Mann-Whitney U Test. The mean score of WOMAC for the experimental and control groups changed from 31.84 to 18.19 and 34.74 to 21.06, respectively, after the intervention. The VAS also showed significant improvements. Significant improvements were observed in WOMAC in both groups after the intervention; however, differences between the groups were not statistically significant., Conclusions: Exercise with either 30∘ or 5∘ of passive dorsiflexion yielded favorable clinical effects. Although submaximal bilateral ankle dorsiflexion was proven to be safe for elderly participants with osteoarthritis of the knee, whether it provided extra benefits to exercises alone was unclear. Further research is required to determine the effectiveness of dorsiflexion and optimal range of mobilization.

During the half time of intermittent team sports, substantial physiological changes relating to acid-base balance and glycemic response affect the second-half performance. Refuel and rehydrate strategy is therefore necessary to be investigated. This field experiment assessed the acute effect of a brief mindfulness-based intervention (MBI) coupled with fluid intake on players' cognitive function in a simulated soccer game. In a single-blinded, randomized, cross-over experiment, 14 male players received three treatments [Control: noncarbohydrate solution + traveling introduction audio; CHO: Carbohydrate (CHO)-electrolyte solution + traveling introduction audio; and CHO-M: CHO-electrolyte solution + MBI] during a simulated half-time break of a soccer game. Participants' mindfulness level, blood glucose and lactate, rating of perceived exertion, and cognitive function performance assessed by the Stroop effect task (ST), Corsi block-tapping test (CBT), and rapid visual information processing task (RVIPT) were immediately measured before, during, and after the trial. Repeated measure ANOVA was used for statistical analysis. The results revealed that: (1) in ST, the CHO_M group performed better than the Control group and marginally better than the CHO group; (2) in CBT, both the Control group and CHO-M group responded faster in the posttest than in the pretest; however, the performance of the CHO group remained the same; (3) the CHO group spent less time on missing numbers in post RVIPT compared with the other two groups. In conclusion, findings of this study provided a preliminary evidence of the positive effect of MBI coupled with CHO intake on athletes' cognitive function, with both positive and negative effect of CHO ingestion., (© Journal of Sports Science and Medicine.)

The Test of Gross Motor Development 2 (TGMD-2) is currently the standard approach for assessing fundamental movement skills (FMS), including locomotor and object control skills. However, its extensive application is restricted by its low efficiency and requirement of expert training for large-scale evaluations. This study evaluated the accuracy of a newly-developed video-based classification system (VCS) with a marker-less sensor to assess children's locomotor skills. A total of 203 typically-developing children aged three to eight years executed six locomotor skills, following the TGMD-2 guidelines. A Kinect v2 sensor was used to capture their activities, and videos were recorded for further evaluation by a trained rater. A series of computational-kinematic-based algorithms was developed for instant performance rating. The VCS exhibited moderate-to-very good levels of agreement with the rater, ranging from 66.1% to 87.5%, for each skill, and 72.4% for descriptive ratings. Paired t-test revealed that there were no significant differences, but significant positive correlation, between the standard scores determined by the two approaches. Tukey mean difference plot suggested there was no bias, with a mean difference (SD) of -0.16 (1.8) and respective 95% confidence interval of 3.5. The kappa agreement for the descriptive ratings between the two approaches was found to be moderate (k = 0.54, p < 0.01). Overall, the results suggest the VCS could potentially be an alternative to the conventional TGMD-2 assessment approach for assessing children's locomotor skills without the necessity of the presence of an experienced rater for the administration., (© Journal of Sports Science and Medicine.)

Objective: The efficacy of two optimization-driven biomechanical modeling approaches has been compared with an electromyography-assisted optimization (EMGAO) approach to predict lumbar spine loading while walking with backpack loads., Background: The EMGAO approach adopts more variables in the optimization process and is complex in data collection and processing, whereas optimization-driven approaches are simple and include the fewest possible variables. However, few studies have been conducted on the efficacy of using the optimization-driven approach to predict lumbar spine loading while walking with backpack loads., Method: Anthropometric information of 10 healthy male adults as well as their kinematic, kinetic, and electromyographic data acquired while they walked with various backpack loads (no-load, 5%, 10%, 15%, and 20% of body weight) served as inputs into the model for predicting lumbosacral joint compression forces. The efficacy of two optimization-driven models, namely double linear optimization with constraints on muscle intensity and single linear optimization without any constraints, was investigated by comparing the resulting force profile with that provided by a current EMGAO approach., Results: The double and single linear optimization approaches predicted mean deviations in peak force of -5.1%, and -19.2% as well as root-mean-square differences in force profile of 16.2%, and 25.4%, respectively., Conclusion: The double linear optimization approach was a relatively comparable estimator to the EMGAO approach in terms of its consistency, slight bias, and efficiency for predicting peak lumbosacral joint compression forces., Application: The double linear optimization approach is a useful biomechanical model for estimating peak lumbar compression forces while walking with backpack loads.

The stiffness matrix is a useful way to describe the mechanical behaviour of the functional spinal unit, which is defined as the superior and inferior vertebrae, capsules and ligaments. This usefulness is extended by means of the concept of the "balance point". The balance point is the load application point where the coupling coefficients of the stiffness matrix are minimized. Theoretical considerations are used to demonstrate that the stiffness matrix varies with load point location and thus a single stiffness matrix does not fully characterize the motion segment as well as to derive the stiffness matrix at any one specified point from the stiffness matrix at some other specified point. Special characteristics of the stiffness matrix obtained by loading through the "balance point" were shown. Some possible advantages derived from mechanical testing using the "balance point" concept are discussed. This study validates an improved stiffness matrix model that enhances the understanding of pathological changes by setting the gold standard of the behaviour of a normal functional spinal unit., (Copyright © 2019 IPEM. Published by Elsevier Ltd. All rights reserved.)

Electromyography-assisted optimization (EMGAO) approach is widely used to predict lumbar joint loads under various dynamic and static conditions. However, such approach uses numerous anthropometric, kinematic, kinetic, and electromyographic data in the computation process, and thus makes data collection and processing complicated. This study developed an electromyography-based support vector machine (EMGB&#95;SVM) approach for predicting lumbar spine load during walking with backpack loads. The EMGB&#95;SVM is simple and uses merely the electromyographic data. Anthropometric information of 10 healthy male adults as well as their kinematic, kinetic, and electromyographic data acquired during walking exercises with no-load and with various backpack loads (5%, 10%, 15%, and 20% of their body weight) were used as the inputs of a biomechanical model, which was then used for predicting the lumbosacral joint compression force. The efficacy of the EMGB&#95;SVM was investigated by comparing the force profiles obtained using this model with those obtained using the current EMGAO approach. On average, the EMGB&#95;SVM obtained deviations in the peak and minimum forces of -3.3% and 5.1%, respectively, and a root mean square difference in the force profile of 7.5%. The EMGB&#95;SVM is a comparable estimator in terms of its slight bias, favourable consistency, and efficiency at predicting the lumbosacral joint compression force., (Copyright © 2019. Published by Elsevier Ltd.)

Background: The fluctuations within stride time series (i.e., stride time variability and complexity) during running exhibit long-range correlation. Detecting the breakdown of the long-range correlation was proposed for monitoring the occurrence of running-related injuries during running. However, the stride time fluctuations were only measured from the unilateral side. In addition, the reliability of the stride time fluctuations of within-subject repeated measures remains largely unknown, particularly during exhaustive running., Purposes: This study investigated between-side and between-day reliabilities of the stride time variability and complexity of right and left sides during an exhaustive running., Methods: The stride time variability and complexity of bilateral sides were obtained while 24 healthy participants performed a 31-minute treadmill running at their individual anaerobic threshold speed. Seven of the 24 participants performed the treadmill running test twice at two different days 5-7 days apart. Limits of agreement (LoA) and intraclass correlation coefficient (ICC) were respectively used to assess the absolute and relative between-side and between-day reliabilities., Results: The stride time variability and complexity of right and left sides were highly symmetrical (LoA: (-0.500%, 0.459%) and (-0.052, 0.051), respectively; ICC: 0.94 (0.87, 0.97) and 0.98 (0.95, 0.99), respectively). The overall stride time variability and complexity revealed good between-day reliability (LoA: (-1.044%, 0.724%) and (-0.067, 0.115), respectively; ICC: 0.78 (0.45, 0.92) and 0.81 (0.48, 0.93), respectively). However, the segmented stride time complexity showed poor between-day reliability (ICCs<0.40)., Conclusion: The findings demonstrated that the stride time series showed equivalent fluctuations between right and left sides and good between-day reliability in fluctuations during exhaustive running. Given the poor between-day reliability in the segmented stride time series, stride time series during exhaustive running could be collected from either right or left side and should be processed as an overall in the future., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Walking with backpack loads induces additional mechanical stress on the spine and has been identified as a risk factor of lower-back pain. This study evaluated the effects of walking with backpack loads on the lumbosacral joint compression force profile in both the magnitude and time domains. Ten male adults geared with anatomical markers and trunk surface electromyographic sensors walked along a walkway embedded with three force plates with no load and various backpack loads (5%, 10%, 15%, and 20% body weight). Lower-body movements, ground reaction forces, and trunk muscle activations were measured using a synchronized motion analysis, force plate, and surface electromyography system. The force profiles of identified gait cycles were predicted using an integrated inverse dynamic and electromyography-assisted optimization model and evaluated statistically. The results showed that as backpack load increased, the 10th, 50th, and 90th percentiles of force profiles escalated disproportionately. However, no significant changes were observed in the timing of the two peak force incidences. Such changes in the compression force might be an indication of the combined effects of the increase in both gravitational and mass moment of inertia of the system (body plus pack loads) when walking with a backpack. Pearson correlation coefficients of the force profiles between the five loading conditions were greater than 0.94. Strong associations between the force profiles at different backpack loads were confirmed., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Measurement of postural stability is crucial for identifying predictors of performance, determining the efficacy of physical training and rehabilitation techniques and evaluating and preventing injuries, particularly for heavy load carriage in hikers, mountain search and rescue personnel and soldiers. This study investigated the effect of load distribution on postural stability in an upright stance using backpack and double pack loads under conflicting or impaired somatosensory, visual and vestibular conditions. The sensory organisation tests were conducted on 20 young adults before and after a 10-min level walking exercise. Young adults' ability to use inputs from somatosensory and visual systems to maintain postural stability was significantly reduced following a 10-min walking exercise with a heavy backpack (30% of body weight), whereas no significant changes were observed for double pack carriage. Thus, the distribution of heavy loads to the front and back provides superior balance control compared with back-only loading. Practitioner summary: This study investigated the effects of heavy (30% of body weight) load distribution on postural stability after a 10-min walking exercise. Backpack carriage significantly reduced postural stability, whereas there was no significant effect under double pack loads. Distribution of heavy loads on the front-and-back is desirable for superior balance control.

Objective: To investigate gender differences in energy expenditure during walking with backpack and double-pack loads., Background: Studies have reported that energy expenditure during walking with double-pack loads is lower compared with backpack carriage. However, the effect of gender on energy expenditure while walking with these two load distribution systems has not been investigated., Method: Thirty healthy young adults (15 female and 15 male participants) walked on a treadmill with backpack and double-pack loads weighing 30% of their body weight at a speed of 0.89 m/s for 10 min. The energy expenditure in terms of oxygen consumption (VO 2 ) and respiratory exchange ratio (RER) were continuously monitored using a portable gas analyzer throughout each walking exercise. A mixed-design analysis of variance model was adopted to test the effects of gender, pack, and time on VO 2 and RER., Results: No time effect was observed on VO 2 . However, significant gender, pack, and interaction effects were observed. The lowest VO 2 was found in female participants under double-pack carriage. No significant gender or pack differences existed in RER. However, RER significantly and incrementally increased in time from the 4th through 6th, 8th, and 10th min., Conclusion: This study revealed that heavy double-pack load carriage for healthy young female participants had significantly lower energy expenditure (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) than that of the male participants in a 10-min walking exercise., Application: The findings of this study indicated that healthy young female participants carried a heavy double-pack with less energy cost (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) compared with their male counterparts during a 10-min walking exercise.

Background: Motor control, related to running performance and running related injuries, is affected by progression of fatigue during a prolonged run. Distance runners are usually recommended to train at or slightly above anaerobic threshold (AT) speed for improving performance. However, running at AT speed may result in accelerated fatigue. It is not clear how one adapts running gait pattern during a prolonged run at AT speed and if there are differences between runners with different training experience., Purposes: To compare characteristics of stride-to-stride variability and complexity during a prolonged run at AT speed between novice runners (NR) and experienced runners (ER)., Methods: Both NR (n = 17) and ER (n = 17) performed a treadmill run for 31 min at his/her AT speed. Stride interval dynamics was obtained throughout the run with the middle 30 min equally divided into six time intervals (denoted as T1, T2, T3, T4, T5 and T6). Mean, coefficient of variation (CV) and scaling exponent alpha of stride intervals were calculated for each interval of each group., Results: This study revealed mean stride interval significantly increased with running time in a non-linear trend (p<0.001). The stride interval variability (CV) maintained relatively constant for NR (p = 0.22) and changed nonlinearly for ER (p = 0.023) throughout the run. Alpha was significantly different between groups at T2, T5 and T6, and nonlinearly changed with running time for both groups with slight differences., Significance: These findings provided insights into how the motor control system adapts to progression of fatigue and evidences that long-term training enhances motor control. Although both ER and NR could regulate gait complexity to maintain AT speed throughout the prolonged run, ER also regulated stride interval variability to achieve the goal., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study investigated the effects of carrying a backpack while walking. Critical changes featuring the disproportionality of increases in trunk muscle activation and lumbar joint loading between light and heavy backpack carriage weight may reveal the load-bearing strategy (LBS) of the lumbar spine. This was investigated using an integrated system equipped with a motion analysis, a force platform and a wireless surface electromyography (EMG) system to measure the trunk muscle EMG amplitudes and lumbar joint component forces. A predictive goal programming model was developed to determine the most critical changes in trunk muscle activation and lumbar joint loading. Results suggested that lightweight backpack carriage at approximately 3% of body weight (BW) might reduce the peak lumbosacral compression force by 3% during walking compared with no load condition. The most critical changes in both trunk muscle activation and lumbosacral joint loading were found at a backpack load of 10% of BW. Practitioner Summary: This study investigated the effects of backpack load on the LBS of lumbar spine while walking. A backpack load of 3% of BW might reduce the peak lumbosacral compression force by 3 and 10% of BW induced the most critical changes in LBS of lumbar spine.

Inertial measurement units (IMUs) have been extensively used to detect gait events. Various methods have been proposed for detecting initial contact (IC) and toe-off (TO) using IMUs affixed at various anatomical locations. However, the accuracy of such methods has yet to be compared. This study evaluated the accuracy of three common methods used for detecting gait events during jogging and running: (1) S-method, in which IC is identified as the instant of peak foot-resultant acceleration and TO is identified when the acceleration exceeds a threshold of 2g in the region of interest; (2) M-method, in which IC and TO are defined as the minimum before the positive peak shank vertical acceleration and the minimum in the region of interest, respectively; and (3) L-method, in which IC is indicated by the instant of peak pelvis anteroposterior acceleration and TO is identified by the maximum in the region of interest. The performance of the IMU-based methods in detecting IC and TO and estimating stance time (ST) were tested on 11 participants at jogging and running speeds against a reference provided by a force-platform method. The S-method was the most accurate for IC detection (overall mean absolute difference (MAD): 4.7±4.1ms). The M-method was the most accurate for TO detection (overall MAD: 7.0±3.5ms). A combination of M- and S-methods, called the MS-method, was the most accurate for ST estimation (overall MAD: 9.0±3.9ms). Thus, the MS-method is recommended for ST estimation; however, this method requires four IMUs for bilateral estimation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Although traction has long been used for treating patients with low back pain (LBP), its effects are still inconclusive mainly because of limited high-quality evidence., Objective: To provide evidence of the mechanism of traction on lumbar intervertebral discs., Design: A quantitative approach with a repeated measurement protocol., Method: Nine participants (mean age = 22.1 ± 0.8 years) without any LBP history were recruited. Magnetic Resonance Images of the lumbar spine of each participant were recorded before and after 30 min of horizontal lying and directly after 30 min of horizontal traction of 42% body weight. The average, anterior, central, and posterior disc height and tilt angle of each lumbar disc and lumbar lordosis were measured., Results: A significant increase in the average disc height for all lumbar discs, a significant reduction of lumbar lordosis and changes in tilt angle were observed after the application of 30 min of resting followed by 30 min of traction. A significant increase in the average disc height was observed only in lower lumbar discs after 30 min of traction. The increase in the posterior disc height was more apparent than that in the anterior disc height., Conclusions: Horizontal traction was evidently effective in increasing the disc height of lower lumbar levels, particularly in the posterior regions of the discs. Further evidence of the effects of traction of different modes, magnitudes, and durations on the change in disc height is required for proper control of traction applied to specific disc levels., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Change in sagittal spinal curvature from the neutral upright stance is an important measure of the heaviness and correctness of backpack use. As current recommendations, with respect to spinal profile, of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the most critical backpack load by assessing simultaneously the spinal curvature changes along the whole spine. A motion analysis system was used to measure the curvature changes in cervical, upper thoracic, lower thoracic and lumbar regions with backpack load at 0, 5, 10, 15 and 20% of body weight. A multi-objective goal programming model was adopted to determine the global critical load of maximum curvature change of the whole spine in accordance with the maximum curvature changes of the four spinal regions. Results suggested that the most critical backpack load was 13% of body weight for healthy male college students. Practitioner Summary: As current recommendations of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the backpack load by considering simultaneously the spinal curvature changes along the whole spine. The recommendation, in terms of the global critical load, was 13% of body weight for healthy male college students.

Previous studies reported that children with cerebral palsy (CP) exhibited premature anticipatory postural adjustments (APAs) with high variability and excessive activity in the frontal plane. To better understand the effects of gross motor functioning level on APAs over the life course, the authors examined the presence and consistency of APAs in 11 adults with diplegia at 2 functioning levels against 8 age-matched healthy adults during unilateral and bilateral reaching. Results revealed an anticipatory vertical torque (TZ) and an increased likelihood of APAs during bilateral reaching for the lower functioning group. It is postulated that APAs may first emerge in TZ in CP. Results also indicated an excessive premovement postural activity in the frontal plane in both CP groups.

Background: Partial body weight-supported treadmill training has been shown to be effective in gait training for patients with neurological disorders such as spinal cord injuries and stroke. Recent applications on children with cerebral palsy were reported, mostly on spastic cerebral palsy with single subject design. There is lack of evidence on the effectiveness of such training for nonspastic cerebral palsy, particularly those who are low functioning with limited intellectual capacity., Objectives: This study evaluated the effectiveness of partial body weight-supported treadmill training for improving gross motor skills among these clients., Study Design: A two-period randomized crossover design with repeated measures., Methods: A crossover design following an A-B versus a B-A pattern was adopted. The two training periods consisted of 12-week partial body weight-supported treadmill training (Training A) and 12-week conventional gait training (Training B) with a 10-week washout in between. Ten school-age participants with nonspastic cerebral palsy and severe mental retardation were recruited. The Gross Motor Function Measure-66 was administered immediately before and after each training period., Results: Significant improvements in dimensions D and E of the Gross Motor Function Measure-66 and the Gross Motor Ability Estimator were obtained., Conclusions: Our findings revealed that the partial body weight-supported treadmill training was effective in improving gross motor skills for low-functioning children and adolescents with nonspastic cerebral palsy. .

Background: Tienchi (Panax notoginseng) has been used in conservative treatments for back pain as a major ingredient of many herbal medicines. This study aims to investigate the effects of a herbal medicine containing tienchi on compressed intervertebral discs in rats., Methods: Using an in vivo rat tail model, intervertebral disc compression was simulated in the caudal 8-9 discs of 25 rats by continuous static compression (11 N) for 2 weeks. An herbal medicine plaster (in which the major ingredient was tienchi) was externally applied to the compressed disc (n=9) for three weeks, and held in place by an adhesive bandage, in animals in the Chinese Medicine (CM) group. The effect of the bandage was evaluated in a separate placebo group (n=9), while no intervention with unrestricted motion was provided to rats in an additional control group (n=7). Disc structural properties were quantified by in vivo disc height measurement and in vitro morphological analysis., Results: Disc height decreased after the application of compression (P < 0.001). The disc height decreased continuously in the control (P = 0.006) and placebo (P = 0.003) groups, but was maintained in the CM group (P = 0.494). No obvious differences in disc morphology were observed among the three groups (P = 0.896)., Conclusion: The tienchi-containing herbal plaster had no significant effect on the morphology of compressed discs, but maintained disc height in rats.

Background: Chronic low back pain (LBP) is a common secondary musculoskeletal problem among adults with cerebral palsy (CP). This study investigated the feasibility of incorporating backpack carriage with daily production activities for relieving chronic LBP among adults with CP., Objectives: The effects of backpack carriage in relieving chronic LBP for adults with CP., Study Design: A multiple bivariate approach with convenience sampling., Methods: Nine adults with CP suffering from chronic LBP were scheduled to carry a 4 lb backpack at work for 60 minutes on weekdays for four consecutive weeks. The pain level was rated by the participants on an 11-point scale. Muscle activity of erector spinae was measured by surface electromyography., Results: Significant improvement in back pain was found immediately after the backpack carriage with no adverse effect reported. It was accompanied with significantly reduced erector spinae activity. Although the overall change in pain ratings across the study period was not significant, a decreasing trend with time was observed., Conclusions: The loaded backpack has the potential to serve as an 'orthosis' for immediate back pain relief among adults with CP. Its underlying mechanism can be attributed to a reduction in back muscle tension during the load carriage.

We present a computer-aided detection (CAD) scheme for early detection of ischemic stroke with small lesions using image feature characteristics. A novel Circular Adaptive Region of Interest (CAROI) method is proposed to analyze the Computed Tomography (CT) images of the brain. Our result indicates that for the emergency physicians and radiology residents, there is a significant improvement in sensitivity and specificity when using CAD (P < 0.005). A mathematical model is established incorporating the weighting of the feature changes. Our CAD scheme is promising for early detection of ischemic stroke and helps improve the efficiency and accuracy of clinical practice., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Study Design: An in vivo rat-tail model was adopted to study the structural changes of degenerated intervertebral disc after different traction protocols., Objective: To investigate the effects of traction with different modes and magnitudes on disc with simulated degeneration., Summary of Background Data: Traction has been commonly used in clinical practice for treating low back pain. Its effects on disc with degeneration have not been fully investigated., Methods: Forty-seven mature rats were used. Continuous static compression of 11 N was applied to the rat caudal 8-9 disc for 2 weeks to simulate disc degeneration. Tractions with different modes (static or intermittent) and magnitudes (1.4 N or 4.2 N) were applied to the degenerated disc for 3 weeks. The disc height was quantified in vivo on days 4, 18, and 39. The treated discs were then harvested for morphologic analysis., Results: Significant decrease in disc height with degenerative morphologic changes was observed after the application of the static compression. The changes in disc height after the application of traction were found to be magnitude dependent. Continuous decrease in disc height was observed after 4.2-N traction, whereas the disc height maintained after traction of 1.4 N. However, no obvious morphologic change was found in comparison with the degenerated discs without traction., Conclusion: Although traction was not demonstrated to have restored disc with degeneration, traction with relatively low magnitude was found to have significant beneficial effect in maintaining disc height of degenerated disc, and it might be a potential intervention to slow down the process of degeneration. Future studies of the effects of low-magnitude traction on degenerated disc are recommended.

Aims: This study aims to identify the needs, concerns and problems of pregnant women when using maternity support garments., Background: Maternity support belt is regarded as helpful in reducing low back pain during pregnancy. However, several garment-related problems exist which might lead to poor adherence behaviour undermining the benefit of garment therapy., Design: A qualitative exploratory study. METHODS. Semi-structured interviews were conducted with 10 pregnant Chinese women who experienced low back pain during pregnancy. All the interviews followed an interview guide and different maternity support garments were shown to the participants as a method of tangible objects to stimulate responses. Content analysis was used to analyse the data., Results: The results showed that 60% of pregnant women discontinued using maternity support garments due to excessive heat, perceived ineffectiveness, itchiness, excessive pressure around the abdomen and inconvenience of adjustment. The content analysis generated five main themes of needs including effective function, safety, skin comfort, ease to put on and take off and aesthetics of maternity support garments., Discussion: The findings of the five main themes of needs were largely consistent with previous studies examining medical garments for overall satisfaction and compliance. The results revealed that women's physiological and psychological changes during pregnancy influenced their clothing preferences on both functional and aesthetical values., Conclusions: Maternity support garments are convenient and easily-accessible therapy to manage LBP during pregnancy and are frequently recommended and worn by pregnant women. However, inappropriate choice of garment therapy not only led to ineffectiveness but also undesirable effects. The key findings of the five main themes of garment needs in pregnant women will facilitate healthcare professionals in providing evidence-based advice to assist patients in the selection of an appropriate and optimal maternity support garment., Relevance to Clinical Practice: These recommendations in the clinical practice will assist patients in making well informed treatment decisions and ultimately improve the quality of care.

Aims: This article aims to review the literature published to date on the types, current use, the biomechanical effects and adverse effects of maternity support belts for low back pain during pregnancy, to identify future research directions., Background: Lumbar/pelvic support belts are frequently recommended for the prevention and treatment of low back pain during pregnancy., Design: Systematic review., Methods: MEDLINE, CINAHL, the Cochrane Library and patents databases were electronically searched., Results: Maternity support belts belong to one of the four main types of maternity support garments, which are widely commercially-available. Current research showed limited evidence in support of the commercial maternity products regarding the effectiveness in the prevention and/or treatment of low back pain during pregnancy, other than that from the manufacturers. However, potential stabilisation effect of maternity support belt was demonstrated in some studies. Adverse effects reported include increased pain, fetal heart rate changes, skin irritation and discomfort., Conclusions: There is insufficient scientific evidence to conclude that wearing maternity support belts reduces pregnancy-related low back pain and/or pelvic girdle pain. Future research directions in the area of biomechanics and physiology are recommended., Relevance to Clinical Practice: This review provides comprehensive understanding of the effectiveness of maternity support belts for the relief of low back pain during pregnancy which will facilitate healthcare professionals in providing evidence-based advice to their patients.

Although spinal manipulation is widely used in the management of neck and pain, its exact mechanisms and biomechancial effects are not clear. A porcine model was used to study the relative movements of intervertebral joints under spinal rotation maneuvers with different input angular displacements and thrust velocities. Ten porcine spines (C2/4) were fixed and mounted in a material testing machine. Rotational maneuvers with different input angular displacements (0.8, 1.5, 2 and 3 degrees) and thrust velocities (0.1 - 200 degrees/s) were applied to C2 with C4 fixed. Angular displacement induced at the adjacent level was measured and expressed as percentage of the applied angular displacement. For all the tested conditions, angular deformation at the adjacent level could not be avoided when an angular thrust was applied to the target level. The percentage of the angular displacement induced at the adjacent level was found to be dependent on both the input angular displacement and thrust velocity. If rapid thurst of manipulation is used to direct the input energy and motion at the target level with minimal interference at the adjacent levels, the applied angular displacement should not be too large and the thrust velocity should be within a medium velocity range.

Background: Both balance control dysfunction and dysfunction of the central nervous system have been proposed as being causative factors in adolescent idiopathic scoliosis (AIS), yet the relationship between these factors has not been investigated in detail. An intergroup comparative study was conducted to investigate the effect of abnormal somatosensory function on the dynamic balance parameters of girls with AIS., Methods: The relationship between dynamic balance control and abnormal somatosensory function seen in AIS patients was examined by studying the dynamic balance parameters in normal controls, in AIS patients with normal posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEPs), and in AIS patients with abnormal PTN-SCEPs. Gait parameters were recorded in 18 AIS girls (8 showing abnormal PTN-SCEPs and 10 showing normal PTN-SCEPs). Eight healthy age-matched volunteers served as a control group., Results: No significant left-right asymmetry of gait parameters was found for the controls or the AIS patients with normal PTN-SCEPs, whereas significantly higher gait parameters were found on the side of the curvature in the AIS patients with abnormal PTN-SCEPs., Conclusions: Somatosensory dysfunction in AIS patients shows to have an impact on dynamic balance control. Further studies to examine the association between somatosensory dysfunction and balance control and how they may be related to the etiology of AIS are recommended., Level of Evidence: Diagnostic study, level IV (case-control study).

Study Design: An in vivo rat-tail model was used to study the effects of static compression with different loading magnitudes and durations on the intervertebral disc., Objective: To investigate the effects of static compression with different loading magnitudes and durations on the intervertebral disc over a period of time., Summary of Background Data: A disc degeneration model is essential for studying therapeutic effects on degenerated disc. Static compression can induce degenerative-like changes in the intervertebral disc. However, the consequences of the simulation model over a period of resting have not been clearly documented, which may have confounding effects on the experimental outcome., Methods: Thirty-five rats were used. Static compressions with different loads (11 or 17 N) and durations (1 hour daily or continuous) were applied to the rat-tail caudal 8-9 disc for 2 weeks, and followed with 3 weeks of rest. The disc height was quantified in vivo on days 4, 18, and 39. The rats were killed and the discs were harvested for morphologic examination on day 39 after the disc height measurement., Results: Significant decrease in disc height was observed after continuous static compression for both 11 and 17 N, and continued during the resting period. The morphologic evaluation of the continuous compressed disc showed a decreased nuclear size, reduced number of nuclear cells, and irregular nuclear shape with inward bulging of disorganized annular collagen lamellas. Daily compression of 1 hour was found to induce a transient increase in disc height, but restored after the 3-week resting period. Favorable morphologic changes, including vacuolated nuclear cells and oval nuclear shape with well-organized annular collagen lamellas, were seen in the rat disc specimens with daily compression of 1 hour., Conclusion: Disc degenerative-like changes without recovery were demonstrated in the rat caudal disc after continuous compression. The changes in disc height and disc morphology were found to be dependent on the duration of load application and may have clinical implication.

Study Design: A prospective study on the comparison of the clinical efficacy and patient's acceptance of the 2 orthotic management methods., Objective: To compare the treatment effectiveness and patients' acceptance of the flexible spinal orthosis, SpineCor with that of the rigid spinal orthosis for the patients with moderate adolescent idiopathic scoliosis., Summary of Background Data: The patients' acceptance to the rigid spinal orthoses is always a concern as it could greatly affect the clinical outcome. SpineCor is a relatively new design for tackling those inevitable drawbacks found in rigid orthosis. However, there was no study to compare this design with the conventional method regarding their treatment efficacy and the patient's acceptance., Methods: Forty-three subjects with moderate adolescent idiopathic scoliosis were randomly assigned to the SpineCor group (S group, n = 22) and rigid orthosis group (R group, n = 21). Their survival rate in the first 45 months of intervention was studied. The subjects' acceptance to the orthoses was evaluated by a purpose-designed questionnaire, which was administered in the 3rd, 9th, and 18th months of intervention., Results: In the study period, there were 68% of the subjects in the S group and 95% of the subjects in the R group did not show curve progression. Significant difference (P = 0.046, by Fisher exact test) in failure rate between the 2 subject groups was found although the 2 groups had similar responses to the questionnaire., Conclusion: The current study showed that the failure rate of the SpineCor was significantly higher than that of the rigid spinal orthosis, and the patients' acceptance to the SpineCor was comparable to the conventional rigid spinal orthosis.

Question: What is the effect of early physiotherapy intervention on pain and patient satisfaction in acute low back pain?, Design: Randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis., Participants: 110 patients attending the Accident and Emergency Department of a local acute hospital., Intervention: The experimental group received early physiotherapy intervention which consisted of education, reassurance, pain management, mobility training, interferential therapy, walking training, and walking aids as indicated. The control group received only walking training and walking aids as indicated. All participants received conventional medical intervention and outpatient physiotherapy intervention., Outcome Measures: Pain was measured using the Numeric Pain Rating Scale and satisfaction was measured using the Numeric Global Rating of Change Scale at baseline, discharge from the Accident and Emergency Department, admission to the Physiotherapy Outpatient Department, 1 month, 3 months, and 6 months., Results: Participants in the experimental group had 1.6 out of 10 points (97.5% CI 0.8 to 2.3) less pain than the control group on discharge from the Accident and Emergency Department and still had 0.9 points (97.5% CI 0.1 to 1.6) less pain on admission to the Physiotherapy Outpatient Department. Participants in the experimental group were 2.1 out of 20 points (97.5% CI 1.2 to 2.9) more satisfied than the control group on discharge from the Accident and Emergency Department., Conclusion: Early physiotherapy intervention was effective in reducing pain and increasing satisfaction for patients with acute low back pain in an Accident and Emergency Department but the effect tailed off.

The balance function of children is known to be affected by carriage of a school backpack. Children with adolescent idiopathic scoliosis (AIS) tend to show poorer balance performance, and are typically treated by bracing, which further affects balance. The objective of this study is to examine the combined effects of school backpack carriage and bracing on girls with AIS. A force platform was used to record center of pressure (COP) motion in 20 schoolgirls undergoing thoraco-lumbar-sacral orthosis (TLSO brace) treatment for AIS. COP data were recorded with and without brace while carrying a backpack loaded at 0, 7.5, 10, 12.5 and 15% of the participant's bodyweight (BW). Ten participants stood on a solid base and ten stood on a foam base, while all participants kept their eyes closed throughout. Sway parameters were analyzed by repeated measures ANOVA. No effect of bracing was found for the participants standing on the solid base, but wearing the brace significantly increased the sway area, displacement and medio-lateral amplitude in the participants standing on the foam base. The medio-lateral sway amplitude of participants standing on the solid base significantly increased with backpack load, whereas significant increases in antero-posterior sway amplitude, sway path length, sway area per second and short term diffusion coefficient were found in participants standing on the foam base. The poorer balance performance exhibited by participants with AIS when visual and somatosensory input is challenged appears to be exacerbated by wearing a TLSO brace, but no interactive effect between bracing and backpack loading was found.

Quantification of changes in intervertebral disc height is critical for studying intervertebral disc degeneration. Reliability of disc height measurement is therefore especially important for in vivo studies using animal models of disc degeneration. In this study, the effects of image intensity and percentage of disc width used for disc height measurement from radiographic images were evaluated in a rat-tail model. Radiographs were taken for 10 Sprague-Dawley rats using a standardized protocol. Average disc heights of the caudal 8-9 discs were determined using original and intensity adjusted images with different percentages of disc width. The average disc height was found to be significantly affected by both the image intensity and the percentage of disc width measured. A higher reliability was found in the measurement for image with adjusted intensity and using smaller disc width. Image intensity is suggested to be controlled and the disc width should be taken into account in quantifying the disc height.

Concerns have been raised regarding the effect of carrying a backpack on adolescent posture and balance, but the effect of backpack loading combined with other factors affecting balance, such as adolescent idiopathic scoliosis (AIS), has not been determined. This study examines the effects of backpack load on the posture and balance of schoolgirls with AIS and normal controls. The standing posture of 26 schoolgirls with mild AIS (mean age 13, Cobb angle 10-25 degrees ) and 20 age-matched normal schoolgirls were recorded without a backpack and while carrying a standard dual-strap backpack loaded at 7.5%, 10%, 12.5% and 15% of the subject's bodyweight (BW). Kinematics of the pelvis, trunk and head were recorded using a motion analysis system and centre of pressure (COP) data were recorded using a force platform. Reliable COP data could only be derived for 13 of the subjects with AIS. Increasing backpack load causes a significantly increased flexion of the trunk in relation to the pelvis and extension of the head in relation to the trunk, as well as increased antero-posterior range of COP motion. While backpack load appears to affect balance predominantly in the antero-posterior direction, differences between groups were more evident in the medio-lateral direction, with AIS subjects showing poor balance in this direction. Overall, carrying a backpack causes similar sagittal plane changes in posture and balance in both normal and AIS groups. Load size or subject group did not influence balance, but the additive effect of backpack carrying and AIS on postural control alters the risk of fall in this population. Therefore, load limit recommendations based on normal subjects should not be applicable to subjects with AIS.

A high degree of gait symmetry is characteristic of healthy gait. The aim of this study is to examine the symmetry of various gait parameters in subjects with unilateral trans-tibial amputation over a range of acceptable anteroposterior translational and tilt alignments, and further to examine if a consistent alignment of highest symmetry can be found. Acceptable alignments were determined by bench, static and dynamic testing on level and non-level surfaces. A total of 15 kinetic and kinematic parameters were then measured in the seven subjects participating in this study. Results indicate that some parameters show consistently higher symmetries, particularly the vertical ground reaction force parameters and the stance duration, step length and time to full knee flexion during the swing phase. Symmetries in other parameters such as knee flexion at loading response, acceleration impulse, and peak anteroposterior propulsive force seem to have little relevance in determining whether the gait pattern for that prosthetic alignment is acceptable or not. While analysis of the symmetry of more relevant gait parameters may assist the prosthetist in consistently and objectively identifying a most symmetrical alignment within the acceptable range, further clinical study is required before any conclusions can be drawn regarding evaluation of symmetry as a tool in defining any optimum alignment.

Adolescent idiopathic scoliosis (AIS) and load-bearing both appear to place similar demands on gait, but no data regarding the combined effects of load-bearing gait in subjects with AIS could be found. The gait patterns of 22 normal adolescent girls and 28 girls with mild AIS (Cobb angle<25 degrees ) were recorded at backpack loads of 0, 7.5, 10, 12.5 and 15% body weight. Temporal-distance and joint kinematic, moment and power parameters were analyzed by repeated measures ANOVA. Findings showed that backpack carriage places an increased demand on the musculature of the lower limb and results in a gait characterized by reduced pelvic motion and greater hip flexion-extension. AIS has a generally similar effect on gait kinematics as backpack carriage, with AIS subjects having significantly longer double support durations, shorter single support durations and lower knee joint power generation and absorption than normal subjects. No interaction between backpack load and AIS was found however, although investigation of parameters indicating a critical response to load showed that this typically occurred at lower backpack loads (7.5% body weight) in the AIS group. Overall, both AIS and load-bearing place increased demands on gait, but carriage of a loaded backpack does not appear to cause any greater demand on subjects with AIS than normal controls.

Study Design: A prospective evaluation of the effects of backpack carriage on the pulmonary function of schoolgirls without spinal deformity versus those with adolescent idiopathic scoliosis (AIS)., Objective: To establish if recommended backpack load limits for normal schoolchildren are also appropriate for study participants with AIS., Summary of Background Data: The weight of schoolchildren's backpacks are of concern because of effects including compromise of pulmonary function. Impaired pulmonary function is also found with AIS, but the effect of backpack carriage on the respiratory parameters of schoolchildren with AIS has not previously been examined., Methods: Forced vital capacity (FVC), forced expiratory volume (FEV1), peak expiratory flow (PEF), and forced expiratory flow (FEF25-75%) were recorded in 17 girls (mean age, 12 years) with moderate AIS (Cobb angle, 26 degrees-50 degrees) and 18 girls (mean age, 11 years) without musculoskeletal deformity during carriage of a backpack loaded at 0%, 5%, 7.5%, 10%, 12.5%, and 15% body weight in random order. Absolute values and proportions of reference values were analyzed by repeated-measures analysis of variance. RESULTS.: No interaction between load and group was found, indicating that backpack loading has a similar effect on the pulmonary function of both normal and AIS groups. However, all recorded pulmonary parameters were found to be significantly lower in the AIS than normal group, significantly so for the referenced FVC and PEF. A significant decrease in FVC and FEV1 was found with increasing backpack load, and the load at which these changes were found to be significant was lower than those established in previous studies., Conclusions: Pulmonary function may be more sensitive to backpack load than previously considered, especially when study participants with AIS are being considered, and the recommended loading limit of 10% body weight may not be applicable to schoolgirls with AIS.

The objective of this study was to assess the effects of acupuncture applied at Hegu (LI 4) points and Neiguan (PC6) points on heart rate variability (HRV) in normal subjects under fatigue and non-fatigue states using power spectral analysis. Twenty-nine normal male subjects were randomly divided into three groups. Subjects in Group A and Group B performed a simulated driving task for 3 h and acupuncture needles were then inserted perpendicularly into the LI 4 points in the middle of the dorsal thenar muscle and PC 6 points situated between the tendons of the palmaris longus and carpi radialis muscles for 15 min for Group A but inserted subcutaneously to the acupuncture points for Group B as a control. Acupuncture needles were directly inserted perpendicularly into the LI 4 points and PC 6 points for 15 min for Group C. Stimulations of the acupuncture points induced a significant decrease in heart rate (HR), HRV total power (TP), low frequency (LF) power and ratio of low frequency to high frequency (LF/HF), and a significant increase in the HF power in normalized units (NU) during the post stimulation period in fatigue state (P<0.05). Stimulation of acupuncture points resulted in a significant increase both in the LF power and HF power in absolute units (AU) (P<0.05) but no significant change in NU was found during the post stimulation period in non-fatigue state. It was concluded that the modulating effect of acupuncture on heart rate variability not only depended on the points of stimulation such as acupuncture or non-acupuncture points but also on the functional state of the subject, namely whether the subjects are in a state of fatigue or not.

The aim of this study was to determine the in vivo kinematics of cervical rotational manipulation in normal subjects and examine the consistency of this technique within and between therapists. A four camera motion analysis system operating at 120 Hz was used to measure the head on trunk angular displacements during manipulation performed by three therapists on eight subjects. One of the therapists performed the manipulation twice for each subject over separate sessions. A consistent pattern of de-rotation prior to thrust was found with little motion other than axial rotation during de-rotation and thrust. The pooled mean de-rotation displacement was 4.8 degrees and the pooled mean thrust angle was 11.3 degrees , but these varied widely, and none of the kinematic parameters recorded proved to be consistent within or between therapists. Most of the kinematic parameters were correlated with the exception of thrust duration. Qualitative analysis shows a consistent technique in cervical rotational manipulation. Pre-manipulation positioning of the head relative to the trunk was fairly consistent for a single therapist over separate sessions, but other than this, the kinematic parameters in cervical rotational manipulation are generally inconsistent within and between therapists.

Concerns regarding the effects of load carriage have led to recommendations that backpacks be limited to 10?-?15% of body weight, based on significant changes in physical performance. However, gait responses to backpack loads are not entirely consistent and there is a particular lack of data regarding load-bearing gait in adolescent females. Gait patterns of 22 normal adolescent girls were recorded at backpack loads of 0, 7.5, 10.0, 12.5 and 15.0% body weight. Temporal-distance, ground reaction force and joint kinematic, moment and power parameters were analysed by repeated measures ANOVA with factors of backpack load and side (left or right). Walking speed and cadence decreased significantly with increasing backpack load, while double support time increased. Kinematic changes were most marked at the proximal joints, with a decreased pelvic motion but a significant increase in the hip sagittal plane motion. Increased moments and power at the hip, knee and ankle showed increasing demand with backpack load. Parameters showed different responses to increasing load, and those that suggested a critical load indicated this to be approximately 10% body weight. While this may be due to a change in gait due to increased demand, further work is required to verify this and also to examine the cumulative effects of backpack load on the musculoskeletal system, which may be more appropriate in determining recommended load limits.

Squat and stoop lifting have been examined in some detail, but limited data exist regarding the sudden release of load during such lifting. Ten participants performed squat and stoop lifting trials with loads of 20, 40, 60 and 80N, and sudden release was randomly included in one of the lifting cycles. Postural perturbation was recorded via centre of pressure displacement using a force platform and the electromyographic response of trunk and lower limb muscles was recorded. Results indicated that irrespective of lifting posture, an 'ankle' response strategy to sudden release was elicited, where the anterior muscles of the lower limb contracted first, followed by the anterior trunk muscles, relaxation of the posterior trunk muscles and, finally, relaxation of the posterior lower limb muscles. The latency of muscles responding by contraction tended to decrease slightly with increasing load for both postures, while the latency of muscles responding by relaxation increased, resulting in increased trunk muscle co-contraction durations. The postural disturbance appeared to be greater for squat lifting than stoop lifting at the higher loads of 60 and 80N, as the centre of pressure moves significantly closer to the posterior limit of static stability (the line joining the heels).In terms of stability and muscular response, squat lifting may not be the most appropriate strategy if a sudden release of loads greater than approximately 50N is likely.

Sudden changes in load during asymmetric lifting may be associated with a particularly high risk of loss of balance and spinal injury. Centre of pressure (COP) motions and electromyographic responses of trunk and lower limb muscles were studied in 10 normal male volunteers during sudden release of 20, 40, 60 and 80N stoop lifting loads in symmetric and asymmetric postures. Similar overall COP responses and muscular response strategies to sudden release of load were seen in both postures, although the asymmetric posture showed a larger medio-lateral COP displacements and greater co-contraction asymmetries. While sudden release of load in asymmetric stoop lifting does not seem to involve a greater risk of fall than symmetric lifting, the muscular response results in more complex and asymmetric loading of the trunk, indicating greater localised segmental loading and therefore increased risk of tissue injury.

While in vitro studies have shown that mechanical loading can result in changes in the composition of intervertebral disc matrix, the effects of cyclic loading in vivo have not been considered. The objective of this study was to assess the effect of static and cyclic compression of different frequencies on the nuclear composition of the intervertebral disc. Thirty-six Sprague-Dawley rats were randomly divided into a control group (no pin insertion, no loading), a sham group (pins inserted in sixth and seventh caudal vertebrae, no loading), a static loading group (compression applied via pins) and cyclic loading groups (loading at 0.5, 1.5 or 2.5 Hz). Loading was applied for 1 h each day from the third to 17th day following pin insertion, and the caudal 5-6, 6-7 and 7-8 discs harvested to quantify proteoglycan content, collagen content and chondrocyte density in the nucleus pulposus. Static compression resulted in a significant reduction in total proteoglycan content as compared with the adjacent control disc, but this effect was not seen in any of the cyclic loading groups. However, comparison with the sham group appears to indicate an overall decrease in total proteoglycan content at the targeted and adjacent levels following cyclic loading. The 0.5 Hz loading group showed a significantly greater total proteoglycan content than all other compression groups, and also showed a lower total collagen content than the sham group. Results suggest that frequency dependent changes in composition occur in response to cyclic loading, but are not limited to the directly loaded disc alone. Further studies are required to verify this, but the choice of control appears to need careful consideration in all studies of this nature.

The effect of fatigue on the muscular and postural response to sudden release of different stoop lifting loads was studied. Ten male volunteers performed a series of stoop lifting trials before and after fatigue of the erector spinae. Trials were performed using loads of 20, 40, 60, and 80 N, and sudden release of load was triggered randomly on one of the repetitions using an electromagnetic release. The onset of release was registered by an accelerometer, centre of pressure (COP) motion was recorded via a forceplate, and EMG activities of the latissimus dorsi (LD), erector spinae (ES), rectus abdominus (RA), external oblique (EO) and internal oblique (IO) muscles were recorded. A slightly reduced lifting speed was seen after fatigue, particularly at the higher loads, but this had little effect on the perturbing force at release, which was dominated by the release load. A significant effect of fatigue was seen on the antero-posterior COP motion, with the postural disturbance being decreased after fatigue. Fatigue resulted in a significant increase in ES (p = 0.029) and LD (p = 0.015) relaxation times and, while the response patterns (relaxation, contraction or no response) of the anterior trunk muscles (RA, EO, IO) were not always consistent, the proportion of response by relaxation was greater after fatigue. This resulted in a lower incidence but longer duration of co-contraction of the ES-RA, ES-EO and ES-EO muscle groups following fatigue, such that the mean co-contraction duration of these groups showed no significant differences before and after fatigue. The response to sudden release is a balance between maintaining postural stability and at the same time preventing the trunk musculature from overloading the spine and risking tissue injury. While fatigue of the trunk extensors does not appear to increase either the risk of fall or stumble or the incidence of co-contraction following sudden release of stoop lifting tasks, the duration of co-contraction appears to increase following fatigue. Further study is required to quantify the loading on the spine during sudden release of different lifting tasks before and after more realistic fatigue conditions.

This paper examines the various design of a multiple-purpose portable functional electrical stimulator which is used in surface stimulation of paralyzed muscle of patients with stroke and results in limb activation. The functionality, circuit performance and reliability of the circuits will be examined. Analysis, design, and experimental results are presented.

Objective: To assess the changes in the multi-planar bending properties of intervertebral joints following cyclic bending along different directions., Design: An in vitro biomechanical study using porcine lumbar motion segments., Background: Repeated bending has been suggested as part of the etiology of gradual prolapse of the intervertebral disc, but the multi-planar changes in bending properties following cyclic loading have not been examined in detail., Methods: Porcine lumbar motion segments were subject to 1500 cycles of bending along directions of 0 degrees (flexion), 30 degrees, 60 degrees, or 90 degrees (right lateral bending). The multi-planar bending moments and hysteresis energies were recorded before loading and after various cycle numbers., Results: Repeated bending at 30 degrees and 60 degrees resulted in greater decreases in mean bending moment and hysteresis energy than bending at 0 degrees or 90 degrees. No significant differences were seen between loading groups for the change in bending moment along the anterior testing directions, but significant differences were observed in the posterior and lateral testing directions, with bending at 30 degrees causing a significantly greater decrease in bending moment in the postero-lateral directions., Conclusions: The change in mechanical properties of porcine intervertebral joints due to cyclic bending depend on the direction of loading and the direction in which the properties are measured. Loading at 30 degrees provokes the most marked changes in bending moment and hysteresis energy.

Background and Objectives: Sudden release of load during lifting threatens postural stability and is countered by trunk muscle response, which can generate high loads on the spine, and may be a cause of tissue injury. The postural threat following sudden release and the consequent muscular response are likely to depend on the posture at the time of release. This study investigates the effects of sudden release of load at two release heights of one- and three-quarters of the knee to shoulder distance during stoop lifting., Methods: Ten normal southern Chinese male volunteers were subject to sudden release of 20, 40, 60 and 80 N loads during stoop lifting trials. The release was randomly selected to be on the third, fourth or fifth cycle of a trial and was triggered at heights of one- and three-quarters of the total knee to shoulder lifting distance. The subjects stood on a force platform to allow the postural disturbance to be recorded by monitoring the center of pressure (COP), and electromyographic (EMG) data were collected from the rectus abdominus, internal oblique, external oblique, erector spinae and latissimus dorsi muscle groups., Results: The COP excursion moved closer to the posterior limit of stability with increasing release load, and this effect was significantly more marked for release from the lower of the two heights. The minimum posterior COP separation from the posterior limit of stability was significantly less for the lower release height at all loads (p<0.001 in all cases). EMG data showed that the agonist-antagonist co-contraction durations were higher for the lower release height, and unlike sudden release from the higher level, showed a significant increase with increasing load., Conclusions: Sudden release at lower release height during stoop lifting results in significantly greater postural disturbance and spinal loading. The mean load predicted to result in fall or stumble at the lower release height (133 N) is significantly less than that predicted at the higher of the two release heights (245 N). A more marked effect of release load is also seen in the postural disturbance and trunk muscle co-contraction time for the lower release height, and particular care should therefore be taken when handling potentially unstable loads under these conditions. If the security of the load cannot be guaranteed, storage at a higher level may reduce the risk of injury due to sudden release of the load.

Objectives: To determine the effect of a series of electro-acupuncture (EA) treatment in conjunction with exercise on the pain, disability, and functional improvement scores of patients with chronic low-back pain (LBP)., Design: A blinded prospective randomized controlled study., Subjects and Interventions: A total of 52 patients were randomly allocated to an exercise group (n = 26) or an exercise plus EA group (n = 26) and treated for 12 sessions., Outcome Measures: Numerical Rating Scale (NRS), Aberdeen LBP scale, lumbar spinal active range of movement (AROM), and the isokinetic strength were assessed by a blinded observer. Repeated measures analysis of variance (R-ANOVA) with factors of group and time was used to compare the outcomes between the two groups at baseline (before treatment), immediately after treatment, 1-month follow-up, and 3-month follow-up. The level of significance was set at p = 0.05., Results: Significantly better scores in the NRS and Aberdeen LBP scale were found in the exercise plus EA group immediately after treatment and at 1-month follow-up. Higher scores were also seen at 3-month follow-up. No significant differences were observed in spinal AROM and isokinetic trunk concentric strength between the two groups at any stage of follow-up., Conclusions: This study provides additional data on the potential role of EA in the treatment of LBP, and indicates that the combination of EA and back exercise might be an effective option in the treatment of pain and disability associated with chronic LBP.

Study Design: Lateral radiographs of the lumbar spine were taken of 40 patients with lumbar spondylolisthesis. These radiographs were taken in the neutral, flexion, and extension positions for both erect and recumbent postures, and also in the prone and supine positions with traction applied via a traction table., Objectives: To define and demonstrate the presence of "vertical instability" in spondylolisthesis, and to determine the most useful radiographic views for clinical purposes and analysis of the surgical principle., Summary of Background Data: Lateral radiographs of patients in flexion and extension are widely used to obtain quantitative and qualitative data on lumbar spondylolisthesis. Changes in lumbar disc height and segmental translation in a group of patients with spondylolisthesis have been demonstrated with the addition of traction and compression., Methods: Lateral and flexion extension radiographs of the lumbosacral spine in 37 patients with spondylolisthesis taken in standing and recumbent positions and under pelvic traction in the prone or supine positions were suitable for analysis. The changes in disc area, intervertebral kyphotic slip angle, and amount of anteroposterior shift (olisthesis) were measured from the radiographs using a computer digitizer. The disc area was normalized against the area of the superior vertebra, and the amount of anteroposterior shift was normalized against the anteroposterior width of the superior vertebra. Inter- and intraobserver error was found to be negligible, and results were analyzed by paired t test., Results: Maximum slip angle, maximum olisthesis, and minimum normalized disc area were found with the subject under erect flexion. Conversely, prone traction and recumbent extension produced minimum slip angle, whereas the lowest anteroposterior shifts were seen with the subject under prone and supine traction. Prone traction also resulted in a significantly larger normalized disc area than any other posture. The change in kyphotic slip angle between erect flexion and prone traction is correlated with the change in normalized olisthesis and disc area., Conclusions: Erect flexion and prone traction radiographs represent the extremes of subluxation and reduction of the olisthesis, respectively, and the change in olisthesis seen between these extremes is correlated with the change in disc area and the intervertebral slip angle. Vertical laxity of the affected functional spinal unit resulting from disc degeneration produces laxity in the ligaments and disc anulus, allowing olisthetic motion. Restoration of disc height in turn restores tension to the soft tissues around the disc and results in a spontaneous reduction of the subluxation. Restoration and maintenance of disc height with a spacer or interbody fusion therefore is recommended as a goal in the treatment of spondylolisthesis. When spondylolytic spondylolisthesis involves a posterior column deficiency, additional reconstruction of this column with posterior instrumentation is recommended. Application of the traction radiographic technique in planning for spondylolisthesis reduction is discussed along with the technique of stabilization.

Objective: To assess the changes in the mechanical properties of inter-vertebral discs in vivo following static and cyclic compressive loading of different frequencies., Design: An in vivo biomechanical study using a rat-tail model of the inter-vertebral disc.Background. Mechanical loading has been suggested as playing a major role in the etiology of disc degeneration, but the relationship is still not fully understood., Methods: Sixty Sprague-Dawley rats were subject to daily compressive stress via pins inserted in the 6th and 7th caudal vertebrae over a two-week loading period. Animals were randomly divided into a sham group (pin insertion, no loading), a static loading group, or cyclic loading groups of 0.5, 1.5, or 2.5 Hz. Loading was applied for 1 h each day from the 3rd to 17th day following pin insertion, and the angular compliance, angular laxity, and inter-pin distance were measured in vivo at days 0, 3, 10 and 17., Results: Changes in the inter-vertebral disc height depended on the frequency of loading, with the decrease in disc height in the static compression group significantly greater than that in all other groups, whereas the decrease in the 1.5 Hz cyclic compression group was significantly smaller than that in all other compression groups., Conclusions: Changes in disc properties depend on both the total load exposure and the frequency of loading. Cyclic loading in general produced less marked changes than static loading, but loading at particular frequencies may result in more severe changes., Relevance: Previous studies have shown the in vivo changes in the mechanical properties of inter-vertebral discs to depend on the magnitude and duration of loading. In this study, a frequency dependent response to cyclic loading is also demonstrated.