Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG

Isokinetic arm and shoulder muscle torque-velocity characteristics in mobility limited children and adolescents with spina bifida

INTRODUCTION

Propulsive wheelchair capacity may be influenced by arm muscle performance.Objectives: To determine whether children and adolescent wheelchair-users with spina bifida show reduced arm muscle strength compared to their typically developing peers and to compare muscle strength data obtained by isokinetic and handheld dynamometry (HHD).

METHODS

Participants (mean age 12.5 ± 2.5 years) were assigned to spina bifida (SB; n = 11) or control (n = 22) groups. Isokinetic dynamometry was used to measure peak torque (PT) during dynamic (60°s-1 and 120°s-1) and isometric strength testing (MVIC) for shoulder and elbow flexors and extensors. HHD was used to measure MVIC of the same muscle groups.

RESULTS

SB showed reduced isokinetic PT for shoulder extensors at 60°s-1 and 120°s-1, shoulder flexor MVIC, and elbow flexors at 60°s-1 and MVIC; higher PT for shoulder flexors and elbow flexors at 120°s-1; and decreased MVIC for elbow flexors but not extensors compared to controls when assessed by HHD. The SB and control groups showed strong positive correlations between MVIC data obtained by the two devices for all muscle groups (r ≥ 0.81; p < .01), except for shoulder flexor MVIC in controls (r = 0.68; p < .01).

CONCLUSION

SB presented reduced levels of dynamic slow-speed and isometric shoulder and elbow muscle strength and greater dynamic high-speed shoulder and elbow flexor strength than controls possibly due to the exposure to self-sustained wheelchair ambulation. Exercise-based intervention protocols to increase slow-speed arm muscle strength should be considered in youth with SB. Strong positive correlations observed between muscle strength assessed by isokinetic dynamometry and HHD support the use of HHD in this clinical population.

Muscle strength, rate of torque development and neuromuscular activation of the upper arm muscles in children and adolescents with spina bifida

BACKGROUND

The use of locomotive devices requires sufficient levels of upper limb strength. Therefore, it is important to evaluate the maximal isometric torque, rate of torque development and neuromuscular activation in youth with spina bifida. The objective was to investigate these parameters in the elbow muscles of youth with spina bifida versus healthy age-matched peers.

METHODS

Forty-eight participants (8-17 years) were recruited: Spina Bifida (n = 23) and non-affected Controls (n = 25). Maximal isometric elbow flexor/extensor contractions were performed to assess maximal muscle strength (peak torque) and rate of torque development, along with synchronized electromyography recording in the biceps and triceps brachii muscles.

FINDINGS

During elbow flexor contractions, Spina Bifida showed reduced rate of torque development in the early contraction phase (0-50 ms) along with lowered relative rate of torque development in the later rate of torque development phase (0-100/200/300 ms) compared to controls. Spina Bifida showed reduced rate of torque development for the elbow extensors in the later phase of rising muscle force (0-200/300 ms) compared to controls. Lower isometric peak torque and smaller triceps brachii electromyography amplitudes (0-200/300 ms) were observed during elbow extensor contractions in Ambulatory spina bifida participants vs. controls.

INTERPRETATION

Although a majority of peak torque and rate of torque development parameters did not differ, significant impairments in maximal and rapid elbow muscle force characteristics were noted in Spina Bifida compared to non-affected Controls. Ambulatory and Non-ambulatory spina bifida participants demonstrated similar rate of torque development in their upper arm muscles.

Electrode Size and Placement for Surface EMG Bipolar Detection from the Brachioradialis Muscle: A Scoping Review

The brachioradialis muscle (BRD) is one of the main elbow flexors and is often assessed by surface electromyography (sEMG) in physiology, clinical, sports, ergonomics, and bioengineering applications. The reliability of the sEMG measurement strongly relies on the characteristics of the detection system used, because of possible crosstalk from the surrounding forearm muscles. We conducted a scoping review of the main databases to explore available guidelines of electrode placement on BRD and to map the electrode configurations used and authors’ awareness on the issues of crosstalk. One hundred and thirty-four studies were included in the review. The crosstalk was mentioned in 29 studies, although two studies only were specifically designed to assess it. One hundred and six studies (79%) did not even address the issue by generically placing the sensors above BRD, usually choosing large disposable ECG electrodes. The analysis of the literature highlights a general lack of awareness on the issues of crosstalk and the need for adequate training in the sEMG field. Three guidelines were found, whose recommendations have been compared and summarized to promote reliability in further studies. In particular, it is crucial to use miniaturized electrodes placed on a specific area over the muscle, especially when BRD activity is recorded for clinical applications.

Properties of the surface electromyogram following traumatic spinal cord injury: a scoping review

Traumatic spinal cord injury (SCI) disrupts spinal and supraspinal pathways, and this process is reflected in changes in surface electromyography (sEMG). sEMG is an informative complement to current clinical testing and can capture the residual motor command in great detail-including in muscles below the level of injury with seemingly absent motor activities. In this comprehensive review, we sought to describe how the sEMG properties are changed after SCI. We conducted a systematic literature search followed by a narrative review focusing on sEMG analysis techniques and signal properties post-SCI. We found that early reports were mostly focused on the qualitative analysis of sEMG patterns and evolved to semi-quantitative scores and a more detailed amplitude-based quantification. Nonetheless, recent studies are still constrained to an amplitude-based analysis of the sEMG, and there are opportunities to more broadly characterize the time- and frequency-domain properties of the signal as well as to take fuller advantage of high-density EMG techniques. We recommend the incorporation of a broader range of signal properties into the neurophysiological assessment post-SCI and the development of a greater understanding of the relation between these sEMG properties and underlying physiology. Enhanced sEMG analysis could contribute to a more complete description of the effects of SCI on upper and lower motor neuron function and their interactions, and also assist in understanding the mechanisms of change following neuromodulation or exercise therapy.

Effects of leucine-enriched essential amino acid supplementation on muscular fatigue and inflammatory cytokines in wheelchair basketball players

PURPOSE

This study aimed to investigate the effects of leucine-enriched essential amino acid (LEAA) supplementation on muscle fatigue and the level of inflammatory cytokines in wheelchair basketball players after a basketball game and interval training.

METHODS

Of the ten recruited wheelchair basketball players (aged 34.5±8.9 years; lean body mass of 34.3±10.0 kg) who had spinal cord injury (SCI) and had undergone amputation, nine participated in the final test. These nine athletes received LEAA supplements (3 times 4.0 g/day) or placebo treatment in a double-blind, randomized, crossover study. We measured variables related to muscular fatigue and inflammatory response before the intense exercise and 4 days after recovery.

RESULTS

The significant effect of LEAA supplementation was inhibition of circulating IL-6 levels in the LEAA-treated group compared with the placebo group (P < .05). However, no changes were observed in the TNF-α and creatinine kinase levels. Moreover, analysis of variance analysis showed no significant difference in the relative values of muscle soreness. However, the effect size analysis with Cohen's d reported a significant improvement in the relative values of whole body and back muscle soreness.

CONCLUSION

Our results revealed that LEAA supplementation before and after intense exercise could help reduce muscle soreness and IL-6 levels in wheelchair basketball players.

Complexity Analysis of Surface Electromyography for Assessing the Myoelectric Manifestation of Muscle Fatigue: A Review

The surface electromyography (sEMG) records the electrical activity of muscle fibers during contraction: one of its uses is to assess changes taking place within muscles in the course of a fatiguing contraction to provide insights into our understanding of muscle fatigue in training protocols and rehabilitation medicine. Until recently, these myoelectric manifestations of muscle fatigue (MMF) have been assessed essentially by linear sEMG analyses. However, sEMG shows a complex behavior, due to many concurrent factors. Therefore, in the last years, complexity-based methods have been tentatively applied to the sEMG signal to better individuate the MMF onset during sustained contractions. In this review, after describing concisely the traditional linear methods employed to assess MMF we present the complexity methods used for sEMG analysis based on an extensive literature search. We show that some of these indices, like those derived from recurrence plots, from entropy or fractal analysis, can detect MMF efficiently. However, we also show that more work remains to be done to compare the complexity indices in terms of reliability and sensibility; to optimize the choice of embedding dimension, time delay and threshold distance in reconstructing the phase space; and to elucidate the relationship between complexity estimators and the physiologic phenomena underlying the onset of MMF in exercising muscles.

The Use of a Wheelchair Propulsion Field Test to Determine Peak Heart Rate in Children and Adolescents With Myelomeningocele

PURPOSE

We analyzed the evolution and pattern of heart rate (HR) during the 12-minute wheelchair propulsion field test (WPFT) and compared the peak HR (HR_peak) from the WPFT to the HR_peak obtained in the progressive cardiopulmonary exercise test on arm cranking ergometer (ACT). We aimed to determine if the field test detects the HR_peak consistently and could be used in clinical practice.

METHODS

Eleven wheelchair-using children and adolescents with myelomeningocele (aged 8-15 y) performed a maximal ACT and a 12-minute WPFT. HR was recorded continuously at rest, during each minute of the tests, and at recovery. Mixed analysis of variance was used to compare the variables at rest and peak. Bland-Altman plot and Lin's concordance correlation coefficient were used to show agreement between the tests.

RESULTS

During minute 2 of the WPFT, participants reached 73%-96% of the HR_peak values recorded in the ACT. From minutes 4 to 12, participants reached HR_peak values ranging 86%-109% of the values recorded in the ACT. There is agreement between the ACT and the WPFT tests.

CONCLUSION

WPFT with minimal duration of 4 minutes may be an alternative tool to obtain HR_peak in children and adolescents with myelomeningocele.

Neuromuscular Responses and Physiological Changes During Small-Sided Games in Wheelchair Basketball

The aim was to analyze the changes of physical performance and physiological responses during a high-intensity training task in wheelchair basketball (WB) players. Thirteen Spanish first division WB male players participated in this study. A test battery (change of direction ability, sprints, and sled towing) was performed to study neuromuscular responses before (pre) and after (post) the small-sided games (SSG). Furthermore, tympanic temperature and blood lactate concentration were measured before and immediately after players finished the SSG. The SSG tasks consisted in four players against four, 4 bouts of 4 min with 2 min of recovery periods. There was a 1.10% decline in performance in both 5- and 20-m sprints (p < .01; effect size [ES] ≤ 0.14), 1.82% decline in 5-m sled towing (p < .05; ES = 0.18), and 2.68% decline in 20-m sled towing (p < .01; ES = 0.27) between pre- and post-SSG. As in physical performance results, significant differences were observed between pre and post in physiological markers, with increasing tympanic temperature (36.21 ± 0.60 °C to 36.97 ± 0.59 °C; p < .001; ES = 1.27) and blood lactate concentrations (1.95 ± 1.30 mmol/L to 5.84 ± 2.04 mmol/L; p < .001; ES = 2.99) after SSG. The SSG produced a decrease in sprint and sled towing performance after 16 min of intense exercise. Moreover, the decrease in physical performance was accompanied with an increase in physiological responses. These neuromuscular responses could be similar in the real game; thus, coaching staff could benefit from this information when changing bench players.

A case report of shoulder fatigue imbalance in wheelchair rugby: implications to pain and injury

The purpose of this case-control study was to examine potential agonist-antagonist fatigue imbalance during wheelchair rugby activity. A 16-channel NORAXON electromyography (EMG) system 1400A with telemetry was used to assess EMG activity in a 39-year-old male with a C6 complete spinal cord injury (American Spinal Injury Association Impairment Scale (AIS) A), 17.5 years post injury. Mean amplitude and median frequency were determined for push-phase agonists (anterior deltoid and pectoralis major) and antagonist (posterior deltoid) across four training sessions at a community fitness and Paralympic training facility. Unlike continuous wheelchair pushing, acute muscle imbalances between agonists and antagonists (that is, push and recovery muscles) were not demonstrated. Wheelchair sports such as rugby may reduce risk of shoulder pain and overuse injury due to intermittent activity rather than continuous pushing. The current study is one of the first to document sport fatigue through electromyography during intermittent, live play rather than clinical conditions (that is, continuous pushing).

The use of a custom-made mouthguard stabilizes the electromyographic activity of the masticatory muscles among Karate-Dō athletes

AIMS

To analyze and compare the electromyographic activity of the temporal (anterior portion) and masseter muscles among Karate-Dō athletes before and after training, with and without the use of a mouthguard.

METHODS

Twenty athletes (14 males and 6 females) with a mean age of 23.7 ± 7.5 years participated. They had surface electromyography recordings taken of their bilateral temporal and masseter muscles before and after training under the following conditions: no mouthguard, with a ready-made mouthguard, and with a custom-made mouthguard. Activity was examined at mandibular rest, while clenching, and at maximum voluntary contraction. The data were normalized using the mean maximum voluntary contraction.

RESULTS

The right (p = 0.005) and left (p = 0.015) temporal muscles showed significantly lower electromyographic activity with a custom-made mouthguard compared with no mouthguard after training while clenching. The electromyographic activity of the temporal and masseter muscles did not show significant differences when tested at mandibular rest and while clenching before or after training with a custom-made mouthguard (p > 0.05).

CONCLUSION

The use of a custom-made mouthguard preserved participants' electromyographic profiles before and after training; thus, they allow for stable muscle activity during the training of Karate-Dō athletes.

SIGNIFICANCE OF THE ELECTROMYOGRAPHIC ANALYSIS OF THE UPPER LIMB MUSCLES OF CRICKET BOWLERS: RECOMMENDATIONS FROM STUDIES OF OVERHEAD-THROWING ATHLETES

The purpose of this study was twofold: (i) to review the existing literature on electromyographic (EMG) analysis of the upper limb muscles of present overhead-throwing (OT) athletes during throwing and of cricket bowlers (CBs) during cricket bowling (CB) and, (ii) to discuss the importance of and generate recommendations for the EMG assessment of the muscle activity of CBs with respect to previous studies of OT athletes. A literature search of the PubMed, Scopus and Google Scholar electronic databases was performed to identify relevant articles published up to December 2012. This search was performed to evaluate the following areas, (i) what are the upper limb muscles that should be evaluated during OT sports and cricket bowling? (ii) what types of EMG methodologies have been used? (iii) what are the anthropometric, performance and physical functional variables that are usually selected? and (iv) what recommendations can be made for the assessment of the muscle activity of CBs? The search identifies 32 publications on OT athletes and 4 on CBs. The results note the following conclusions: (i) there are relatively few CB-related papers that utilize EMG, particularly for the assessment of muscle activity and coordination, (ii) a total of 22 upper limb muscles were investigated using EMG (from both criteria), (iii) surface electrodes are used more frequently than needle electrodes, (iv) most of the article normalized and analyzed the EMG amplitudes than the frequency, and the data was more often analyzed through a descriptive statistical analysis and (v) the majority of the studies analyzed the right limb of physically normal (uninjured) male's both the amateur and professional athletes that were 20 to 29 years of age. Finally, the published evidence on CBs is inadequate to validate a sound recommendation for the assessment of the muscles of CBs using EMG. However, the studies on OT athletes do provide guidelines that can be used to analyze CBs. The overall conclusion of this review show that, further studies are needed to evaluate the efficacy of EMG for the assessment of the upper limb muscle of CBs to ultimately identify and prevent injury which is still a matter of discussion in the sports medicine community.