Surface electromyography as a measure of trunk muscle activity in patients with spinal cord injury: a meta-analytic review

Exercise therapy can effectively improve trunk performance and sitting balance in spinal cord injury: a systematic review and meta-analysis

OBJECTIVE

To determine the effects of exercise on trunk performance and balance in patients with spinal cord injury (SCI).

METHODS

We searched the databases MEDLINE, Cochrane Library, EMBASE, Physiotherapy Evidence Database, Web of Science, PsycINFO, and CINAHL from inception to June 2020. Our search targeted studies such as randomized or non-randomized controlled trials and randomized crossover trials that evaluated the effects of exercise on trunk performance and balance in patients with SCI.

RESULTS

Seventeen eligible studies with 432 patients with SCI were included in the meta-analysis. The exercise significantly improved several measures: Berg Balance Scale (mean differences [MD] = 4.58; 95% confidence intervals [CI], 0.35, 8.8; p = 0.03), Modified Functional Reach Test (MD = 5.29; 95% CI, 4.16, 6.42; p < 0.01), T-shirt test (MD = 5.62; 95% CI, - 3.82, - 7.42; p < 0.01), Timed Up and Go (MD = - 1.70; 95% CI, - 0.23, - 3.16; p = 0.02). Improvements were also noted in total static sitting balance (standardized mean differences [SMD] = 1.21; 95% CI, 0.79, 1.63; p < 0.01), and total dynamic sitting balance (SMD = 1.01; 95% CI, 0.30, 1.73; p < 0.01). In the subgroup analysis, exercise with sensory input enhancement significantly improved total static (SMD = 1.37; 95% CI, 0.64, 2.11; p < 0.01) and total dynamic sitting balance (SMD = 1.78; 95% CI, 0.28, 3.29; p = 0.02).

CONCLUSIONS

Exercise may improve sitting balance in patients with SCI. Moreover, enhancement of sensory input had an add-on effect in improving sitting balance.

REGISTRATION

PROSPERO (CRD42020185904).

Changes in thoracic erector spinae regional activation during postural adjustments and functional reaching tasks after spinal cord injury

Many individuals with incomplete spinal cord injury (SCI) exhibit reduced volitional control of trunk muscles, such as impaired voluntary contractions of the erector spinae (ES), due to damage to the neural pathways regulating sensorimotor function. Studies using conventional bipolar electromyography (EMG) showed alterations in the overall, or global, activation of the trunk muscles in people with SCI. However, how activation varied across specific regions within the ES, referred to as regional activation, remains unknown. The aim of the study was to investigate the regional distribution of the ES activity below the level of injury in individuals with incomplete SCI during postural tasks and multidirectional reaching tasks using high-density EMG. Twenty-one individuals with incomplete SCI and age-matched controls were recruited. The EMG amplitude of the thoracic ES and displacement of the arm, trunk, and center of pressure were recorded during the tasks. Activation was more in the lower region of the ES in individuals with SCI than in the controls during the postural tasks. In addition, activation was limited to a small area of the ES during the reaching tasks. The EMG amplitude was greater during reaching forward than returning to the upright posture in the controls; however, this phase-dependent difference in the EMG amplitude was not present in individuals with SCI. Our findings demonstrate changes in regional activation of the thoracic ES during postural and reaching tasks, likely reflecting injury-induced changes in selective neural control to activate residual muscle fibers of the ES for postural control and function after SCI.NEW & NOTEWORTHY We demonstrate that individuals with chronic incomplete spinal cord injury (SCI) recruit lower part of the thoracic erector spinae (ES) for postural control of the trunk. We also show that activation was restricted in a smaller part of the ES, and the discrete control of the ES was lost during functional reaching movements in individuals with SCI. Our study provides evidence of alterations in neural control between vertebral levels in individuals with SCI.

The trunk segmental motion complexity and balance performance in challenging seated perturbation among individuals with spinal cord injury

BACKGROUND

Motion complexity is necessary for adapting to external changes, but little is known about trunk motion complexity during seated perturbation in individuals with spinal cord injury (SCI). We aimed to investigate changes following SCI in trunk segmental motion complexity across different perturbation directions and how they affect postural control ability in individuals with SCI.

METHODS

A total of 17 individuals with SCI and 18 healthy controls participated in challenging sagittal-seated perturbations with hand protection. Upper arm activation was measured using surface electromyography for trial consistency. Motion complexity parameters, quantified across three degrees of freedom, was assessed using relative angular acceleration from six trunk segments obtained through motion capturing system. Motion performance parameters were assessed using center of pressure (CoP) measurements from a force plate, including settling time, maximum CoP displacement (MD) variability, and steady-state error. Statistical analyses examined group and direction differences, while complexity-performance relationships were evaluated using multiple response least partial squares regression.

RESULTS

Compared to healthy controls, individuals with SCI showed significantly lower motion complexity in the lumbar and upper thoracic segments (approximately10% - 20%), with identical settling time and higher MD variability. Backward perturbations, as opposed to forward perturbations, resulted in reduced complexity in the aforementioned segments and increased steady-state error. Lower lumbar rotation complexity negatively correlated with MD variability (β = -0.240) and steady-state error (β = -0.485) in individuals with SCI, while showing a minor positive correlation with settling time (β = 0.152) during backward perturbation.

CONCLUSION

Simplified motion control in individuals with SCI may arise from uncoordinated lumbar and overactive thoracic neuromuscular control, compromising stability despite maintaining speed. Increasing lumbar motion complexity could enhance postural stability and accuracy during backward perturbation, representing a potential target for developing seated balance rehabilitation strategies and promoting more adaptive trunk control.

Surface electromyography: A pilot study in canine spinal muscles

In veterinary practice, rehabilitation modalities are often used to help in the recovery of animals affected by InterVertebral Disc Disease (IVDD), a condition frequently observed in chondrodystrophic dog breeds and can lead to Spinal Cord Injury (SCI), resulting in pain, motor impairments and neurological deficits, but there is a lack of objective assessment tools for patient evolution. In this work, an innovative approach using surface ElectroMyoGraphy (sEMG) is proposed to be applied in the field of veterinary medicine rehabilitation. The observed results are thought to be a direct result of nerve compression, leading to unusual patterns of muscle activation; this phenomenon can be attributed to muscle denervation, where the loss of Motor Units (MU) is the primary cause. This is thought to be responsible for the decrease in recorded sEMG amplitude and the increase in frequency observed in the pathological group.•This study involved rigorous animal preparation and signal acquisition protocols, involving multiple exercises and sub-movements, which were subsequently analysed.•RMSA is most used metric to analyse amplitude in sEMG signals, as it results in a more representative measurement of the signal variability than the Mean amplitude or the Standard Deviation.

Effectiveness study of surface electromyography combined with spine 3D data system to evaluate scoliosis

OBJECTIVE

To evaluate the clinical effectiveness of surface electromyography combined with a spine 3D data system.

METHODS

10 idiopathic scoliosis patients (age: 12.90±3.67 years, height: 155.90±20.07 cm, weight: 48.00±12.86 kg, 6 major thoracic lateral bends and 4 lumbar bends) who were selected to attend the outpatient clinic of Ruijin Rehabilitation Hospital, First diagnosed as scoliosis by imaging examination (EOS system), evaluation by using the surface electromyography monitoring system, the radiation-free 3D spine data acquisition and analysis system, the surface electromyography of the paravertebral muscles (root mean square value (RMS) of the resting standing and action position of the spine) and the Cobb angle of scoliosis were recorded.

RESULTS

The RMS of the convex side was larger than that of the concave side in the two postures (P<0.05), and The RMS value of bilateral action position was significantly higher than that of rest position (P<0.05). There was no correlation between RMS ratio and Cobb angle in two positions of thoracic scoliosis (P>0.05). There was a significant correlation between the RMS ratio at rest position of lumbar scoliosis and Cobb angle. At rest, the RMS value of convex side was significantly correlated with the Cobb angle measured by the EOS system and the 3D data system (P<0.05, of which P<0.01). The Cobb angle measured by 3D data system and the EOS system was significantly correlated (P<0.01).

CONCLUSION

Surface EMG can be used to evaluate the motor function of paravertebral muscles on both sides of scoliosis patients. The new 3D data system has high accuracy in evaluating scoliosis. The combination of the two can dynamically evaluate scoliosis, which is more clinically effective.

Utilizing spinal cord injury stratification during classification for allocation of para surfing sport classes

OBJECTIVES

The purpose of this study was to determine which stratification (anatomical versus functional) forms a better construct for classification of para surfers with spinal cord injury; to assess the groupings of these para surfers; and to evaluate the strength of association between manual muscle testing and surfing performance.

DESIGN

Cross-sectional.

METHODS

Archived data from classification records including demographics, spinal cord injury levels, trunk strength, and limb strength were compared to judged wave scores and competition rankings.

RESULTS

Participants (n = 70, male n = 56; female n = 14) met inclusion criteria and were classified into Para Surfing Kneeling (n = 9); Sit (n = 11); Prone 1 (n = 25); and Prone 2 (n = 25) sport classes. Reliability statistics showed that functional grouping (Cronbach's α = 0.759) is better grouped with strength testing and rankings compared to anatomical grouping (Cronbach's α = 0.721). Under exploratory factor analysis with 2 fixed components, based on the factor loadings (rank and strength) functional stratification (0.978) is better aligned compared to anatomical stratification (0.785) for grouping of surfers. Further, the association and impact of strength with functional spinal cord level stratification were confirmed using regression analysis (chi-square of 74.06 with p-value <.0001).

CONCLUSIONS

Trunk and limb strengths have been shown to influence wave riding performance in surfers with spinal cord injury. Surfers with spinal cord injury can equitably be classified into one of the four para surfing sport classes. The use of functional stratification of spinal cord injury with trunk and limb strengths should be considered as an integral component in para surfing athlete sport classification.

Upper limb electromyographic analysis of manual wheelchair transfer techniques in individuals with spinal cord injury: A systematic review

BACKGROUND AND PURPOSE

The objective of this study is to determine the upper limb muscle electromyographic (EMG) activity required during various manual wheelchair transfers in the population of spinal cord injury (SCI).

METHODS

This review included observational studies reporting the (EMG) activity of upper limb muscles during wheelchair transfers in people with SCI. We searched electronic databases and reference lists of relevant literature between 1995 and March 2022 with English language limits, yielding 3870 total articles. Two independent researchers performed data extraction and conducted quality assessment using two checklists, the Modified Downs and Blacks and National Heart, Lung, and Blood Institute for observational cohort and cross-sectional studies.

RESULTS

After eligibility screening, seven studies were included in this review. The sample size ranged from 10 to 32 participants aged 31-47 years. They assessed four types of transfers and mostly evaluated six upper limb muscles were biceps, triceps, anterior deltoid, pectoralis major, latissimus dorsi and ascending fibres of the trapezius. The peak EMG value indicated that muscle recruitment varied in both upper limbs according to the task demand, and the highest activity was seen during the lift-pivot transfer phase. Because of the data heterogeneity, a meta-analysis of study results was not feasible.

CONCLUSION

There were various ways of reporting the upper limb EMG muscle activity profile across all the included studies with a limited sample size. The crucial role of upper limb muscles during different types of manual wheelchair transfers was interpreted in this review. This is essential for predicting functional independence of individuals with SCI and warranting optimal rehabilitation strategies for wheelchair transfer skills.

Research Hotspots of the Rehabilitation Medicine Use of sEMG in Recent 12 Years: A Bibliometric Analysis

Objective

Surface electromyography (sEMG) has been widely applied to rehabilitation medicine. However, the bibliometric analysis of the rehabilitation medicine use of sEMG is vastly unknown. Therefore, this research aimed to investigate the current trends of the rehabilitation medicine use of sEMG in the recent 12 years by using CiteSpace (5.8).

Methods

Literature relating to rehabilitation medicine use of sEMG from 2010 to 2021 was retrieved from the Web of Science. CiteSpace analyzed country, institution, cited journals, authors, cited references and keywords. An analysis of counts and centrality was used to reveal publication outputs, countries, institutions, core journals, active authors, foundation references, hot topics and frontiers.

Results

A total of 1949 publications were retrieved from 2010 to 2021. The total number of publications continually increased over the past 12 years, and the most active countries, institutions, journals and authors in rehabilitation medicine use of sEMG were identified. The most productive country and institution in this field were America (484) and the University of Sao Paulo (36). Andersen LL (28) was the most prolific author, and Dario Farina ranked first among the cited authors. Besides, there were three main frontiers in keywords for sEMG research, including “activation”, “exercise”, and “strength”.

Conclusion

The findings from this bibliometric study provide the current status and trends in clinical research of rehabilitation medicine use of sEMG over the past ten years, which may help researchers identify hot topics and explore new directions for future research in this field.

Clinical Trials Using Mesenchymal Stem Cells for Spinal Cord Injury: Challenges in Generating Evidence

Spinal cord injury (SCI) remains an important public health problem which often causes permanent loss of muscle strength, sensation, and function below the site of the injury, generating physical, psychological, and social impacts throughout the lives of the affected individuals, since there are no effective treatments available. The use of stem cells has been investigated as a therapeutic approach for the treatment of SCI. Although a significant number of studies have been conducted in pre-clinical and clinical settings, so far there is no established cell therapy for the treatment of SCI. One aspect that makes it difficult to evaluate the efficacy is the heterogeneity of experimental designs in the clinical trials that have been published. Cell transplantation methods vary widely among the trials, and there are still no standardized protocols or recommendations for the therapeutic use of stem cells in SCI. Among the different cell types, mesenchymal stem/stromal cells (MSCs) are the most frequently tested in clinical trials for SCI treatment. This study reviews the clinical applications of MSCs for SCI, focusing on the critical analysis of 17 clinical trials published thus far, with emphasis on their design and quality. Moreover, it highlights the need for more evidence-based studies designed as randomized controlled trials and potential challenges to be addressed in context of stem cell therapies for SCI.

Comparison of the postoperative changes in trunk and lower extremity muscle activities between patients with adult spinal deformity and age-matched controls using surface electromyography

STUDY DESIGN

A prospective study.

OBJECTIVE

To investigate the paravertebral and lower extremity muscle activities using surface electromyography (S-EMG) in patients with adult spinal deformity (ASD) comparing with those of age-matched controls. Although the paravertebral muscle is greatly involved in ASD pathology, little is known about the contribution of lower extremity muscle on maintaining standing posture.

METHODS

Fourteen patients with ASD (1 man, 13 women; mean age, 67.1 years) who underwent corrective fusion surgery with at least 2 years of follow-up and age-matched controls (1 men, 7 women; mean age, 69.3 years) were enrolled. The muscle activities of the thoracic and lumbar erector spinae (TES and LES), external oblique (EO), gluteus maximus (GM), rectus femoris (RF), and biceps femoris (BF) were recorded in the upright and anterior flexion positions using S-EMG pre-operatively and 1 year post-operatively.

RESULTS

Compared with controls, patients showed a significantly higher muscle activity in the LES and BF at rest in a standing position. After corrective fusion surgery, the muscle activity of LES decreased and that of RF increased (p < 0.05), and the changes reached the level of the controls. When the posture changed from upright to anterior flexion, the controls showed increased muscle activity of the BF, whereas the patients showed decreased muscle activity of the TES and RF and increased muscle activity of the BF. Post-operatively, muscle activity of the TES, LES, GM, and BF increased and that of the RF decreased.

CONCLUSIONS

ASD patients required a higher activity of the lower extremity and trunk muscles to maintain a standing position compared to the age-matched controls. Significant increase of the GM, BF, and TES muscle activities during anterior bending suggest the presence of mechanical stress concentration caused by fixed lumbar spine.

LEVEL OF EVIDENCE

Level III.

Wavelet coherence as a measure of trunk stabilizer muscle activation in wheelchair fencers

BACKGROUND

Intermuscular synchronization constitutes one of the key aspects of effective sport performance and activities of daily living. The aim of the study was to assess the synchronization of trunk stabilizer muscles in wheelchair fencers with the use of wavelet analysis.

METHODS

Intermuscular synchronization and antagonistic EMG-EMG coherence were evaluated in the pairs of the right and the left latissimus dorsi/external oblique abdominal (LD/EOA) muscles. The study group consisted of 16 wheelchair fencers, members of the Polish Paralympic Team, divided into two categories of disability (A and B). Data analysis was carried out in three stages: (1) muscle activation recording using sEMG; (2) wavelet coherence analysis; and (3) coherence density analysis.

RESULTS

In the Paralympic wheelchair fencers, regardless of their disability category, the muscles were activated at low frequency levels: 8-20 Hz for category A fencers, and 5-15 Hz for category B fencers.

CONCLUSIONS

The results demonstrated a clear activity of the trunk muscles in the wheelchair fencers, including those with spinal cord injury, which can be explained as an outcome of their intense training. EMG signal processing application have great potential for performance improvement and diagnosis of wheelchair athletes.

Quantitative evaluation of trunk function and the StartReact effect during reaching in patients with cervical and thoracic spinal cord injury

Objective.Impaired trunk stability is frequent in spinal cord injury (SCI), but there is a lack of quantitative measures for assessing trunk function. Our objectives were to: (a) evaluate trunk muscle activity and movement patterns during a reaching task in SCI patients, (b) compare the impact of cervical (cSCI) and thoracic (tSCI) injuries in trunk function, and (c) investigate the effects of a startling acoustic stimulus (SAS) in these patients.Approach.Electromyographic (EMG) and smartphone accelerometer data were recorded from 15 cSCI patients, nine tSCI patients, and 24 healthy controls, during a reaching task requiring trunk tilting. We calculated the response time (RespT) until pressing a target button, EMG onset latencies and amplitudes, and trunk tilt, lateral deviation, and other movement features from accelerometry. Statistical analysis was applied to analyze the effects of group (cSCI, tSCI, control) and condition (SAS, non-SAS) in each outcome measure.Main results.SCI patients, especially those with cSCI, presented significantly longer RespT and EMG onset latencies than controls. Moreover, in SCI patients, forward trunk tilt was accompanied by significant lateral deviation. RespT and EMG latencies were remarkably shortened by the SAS (the so-called StartReact effect) in tSCI patients and controls, but not in cSCI patients, who also showed higher variability.Significance. The combination of EMG and smartphone accelerometer data can provide quantitative measures for the assessment of trunk function in SCI. Our results show deficits in postural control and compensatory strategies employed by SCI patients, including delayed responses and higher lateral deviations, possibly to improve sitting balance. This is the first study investigating the StartReact responses in trunk muscles in SCI patients and shows that the SAS significantly accelerates RespT in tSCI, but not in cSCI, suggesting an increased cortical control exerted by these patients.

ANALYSIS OF DIFFERENT INJURIES OF BASKETBALL PLAYERS BASED ON SURFACE ELECTROMYOGRAPHY

ABSTRACT Assessing the performance of basketball players is very important in the implementation of technical training programs. The application of electromyography (EMG) in basketball players is still relatively small. The evaluation of athletes’ muscle state index by EMG can guide sports training. This study used surface electromyography to test and compare EMG data, analyze muscle discharge timing, contribution rate and integral EMG value of the turning movement, aiming to explore the prevention mechanism of different types of injury affecting basketball players. The synchronous measurement model of EMG signal and plantar pressure curve in jump shot process of basketball players is established to deepen coaches’ understanding of jump shot movement rules and guide athletes to conduct scientific jump shot training. The research shows that the incidence of knee joint injury is relatively high in basketball players. Patella strain and softening, knee meniscus injury and cruciate ligament injury are the main types of injury, and there is no difference between genders.

Assessment of trunk flexion in arm reaching tasks with electromyography and smartphone accelerometry in healthy human subjects

Trunk stability is essential to maintain upright posture and support functional movements. In this study, we aimed to characterize the muscle activity and movement patterns of trunk flexion during an arm reaching task in sitting healthy subjects and investigate whether trunk stability is affected by a startling acoustic stimulus (SAS). For these purposes, we calculated the electromyographic (EMG) onset latencies and amplitude parameters in 8 trunk, neck, and shoulder muscles, and the tilt angle and movement features from smartphone accelerometer signals recorded during trunk bending in 33 healthy volunteers. Two-way repeated measures ANOVAs were applied to examine the effects of SAS and target distance (15 cm vs 30 cm). We found that SAS markedly reduced the response time and EMG onset latencies of all muscles, without changing neither movement duration nor muscle recruitment pattern. Longer durations, higher tilt angles, and higher EMG amplitudes were observed at 30 cm compared to 15 cm. The accelerometer signals had a higher frequency content in SAS trials, suggesting reduced movement control. The proposed measures have helped to establish the trunk flexion pattern in arm reaching in healthy subjects, which could be useful for future objective assessment of trunk stability in patients with neurological affections.

Energy expenditure and muscle activity during lying, sitting, standing, and walking in people with motor-incomplete spinal cord injury

STUDY DESIGN

Cross-sectional exploratory study.

OBJECTIVES

To determine oxygen uptake (VO₂), energy expenditure (EE), and muscle activity (MA) during lying (rest), sitting, standing, and walking among ambulatory individuals with spinal cord Injury (SCI) and to compare VO₂, EE, and MA between individuals with different levels of ambulation.

SETTING

Rehabilitation institution with a spinal cord injury unit.

METHODS

A total of 22 adults with motor-incomplete SCI, ten in a low-ambulation group (non-functional or household walker) and 12 in a high-ambulation group (community or normal walker). VO₂ was measured using indirect calorimetry. EE was expressed in metabolic equivalent of task (MET). MA was measured using a wireless surface electromyography device.

RESULTS

Mean VO₂ was 3.19 ml/kg/min. During lying and sitting, EE was below 1.5 METs for all participants. During standing, three participants of the low-ambulation group and none in the high-ambulation group showed MET values of >1.5. In the walking condition, all participants showed MET values above 1.5. MA during stance was higher compared to the sitting condition and significantly higher in the low-ambulation group compared to the high-ambulation group.

CONCLUSION

Lying, supported- and unsupported sitting, without moving, appear to be sedentary behaviors for ambulatory individuals with a motor-incomplete SCI (MET values of <1.5 and a lack of MA). Walking, but not standing, is a moderate physical activity (>1.5 METs), which can be used by all individuals with motor-incomplete SCI to interrupt sedentary behavior.

Effects of Stand and Step Training with Epidural Stimulation on Motor Function for Standing in Chronic Complete Paraplegics

Individuals affected by motor complete spinal cord injury are unable to stand, walk, or move their lower limbs voluntarily; this diagnosis normally implies severe limitations for functional recovery. We have recently shown that the appropriate selection of epidural stimulation parameters was critical to promoting full-body, weight-bearing standing with independent knee extension in four individuals with chronic clinically complete paralysis. In the current study, we examined the effects of stand training and subsequent step training with epidural stimulation on motor function for standing in the same four individuals. After stand training, the ability to stand improved to different extents in the four participants. Step training performed afterwards substantially impaired standing ability in three of the four individuals. Improved standing ability generally coincided with continuous electromyography (EMG) patterns with constant levels of ground reaction forces. Conversely, poorer standing ability was associated with more variable EMG patterns that alternated EMG bursts and longer periods of negligible activity in most of the muscles. Stand and step training also differentially affected the evoked potentials amplitude modulation induced by sitting-to-standing transition. Finally, stand and step training with epidural stimulation were not sufficient to improve motor function for standing without stimulation. These findings show that the spinal circuitry of motor complete paraplegics can generate motor patterns effective for standing in response to task-specific training with optimized stimulation parameters. Conversely, step training can lead to neural adaptations resulting in impaired motor function for standing.