Non-invasive spinal cord electrical stimulation for arm and hand function in chronic tetraplegia: a safety and efficacy trial.

Cervical spinal cord injury (SCI) leads to permanent impairment of arm and hand functions. Here we conducted a prospective, single-arm, multicenter, open-label, non-significant risk trial that evaluated the safety and efficacy of ARCEX Therapy to improve arm and hand functions in people with chronic SCI. ARCEX Therapy involves the delivery of externally applied electrical stimulation over the cervical spinal cord during structured rehabilitation. The primary endpoints were safety and efficacy as measured by whether the majority of participants exhibited significant improvement in both strength and functional performance in response to ARCEX Therapy compared to the end of an equivalent period of rehabilitation alone. Sixty participants completed the protocol. No serious adverse events related to ARCEX Therapy were reported, and the primary effectiveness endpoint was met. Seventy-two percent of participants demonstrated improvements greater than the minimally important difference criteria for both strength and functional domains. Secondary endpoint analysis revealed significant improvements in fingertip pinch force, hand prehension and strength, upper extremity motor and sensory abilities and self-reported increases in quality of life. These results demonstrate the safety and efficacy of ARCEX Therapy to improve hand and arm functions in people living with cervical SCI. ClinicalTrials.gov identifier: NCT04697472 .

Occurrence of injuries and illnesses in athletes with a physical impairment; a forty-week prospective cohort study.

OBJECTIVES: Currently, the knowledge about the epidemiology of sport-related health problems of athletes with a physical impairment is limited. Therefore, this study aims to describe the prevalence, incidence and severity of sport-related health problems of athletes with a physical impairment in the Netherlands over a one sport season. DESIGN: Prospective cohort study. METHODS: Athletes (n = 99) with a physical impairment participated in this study. After completing a baseline questionnaire, athletes started a 40-week health monitoring period, during which they completed the Dutch translation of the OSTRC Questionnaire on Health Problems every week. Based on the reported information, injury and illness prevalence, incidence, weekly cumulative severity score, weekly time loss from sport and the total burden were calculated. RESULTS: A total of 368 health problems were reported by 95 athletes. These health problems consisted of 258 injuries and 110 illnesses. The average weekly prevalence of health problems was 48.0 %; for injuries 34.6 %, and illnesses 13.4 %. Differences were found when considering injury severity, with the highest severity scores for athletes with a limb deficiency. Furthermore, recreational athletes reported the highest injury severity scores, followed by athletes who competed nationally and athletes who competed internationally. CONCLUSIONS: Data from this study show a high average weekly prevalence of health problems, and differences amongst various impairment categories and sport levels when considering the severity of injuries. These results add to the knowledge regarding sport-related health problem epidemiology in this population, indicating that impairment category and sport level should be taken into account when developing injury prevention strategies.

The Effect of Mindset and Breathing Exercises on Physical and Mental Health in Persons with Spinal Cord Injury-A Pilot Feasibility Study.

This study investigated the feasibility and efficacy of mindset and breathing exercises (Wim Hof Method (WHM)) on physical and mental health in persons with spinal cord injury (SCI). Ten individuals with SCI participated in this pilot study. These ten participants followed a 4-week WHM intervention, with one weekly group session in the rehabilitation center and daily practice at home using the WHM app. An in-person exit-interview was conducted post-intervention to collect qualitative information on participants' experiences, regarding the feasibility and effects of the intervention. Furthermore, tests and questionnaires were administered pre- and post-intervention to assess physical and mental health outcomes. Adherence to the weekly in-person meetings was excellent and no adverse events occurred. Physical and mental health outcomes in this small sample size showed some pre-post differences. This pilot feasibility study provides preliminary evidence supporting the feasibility and efficacy of the WHM, including mindset and breathing exercises, on physical and mental health of people with SCI. These results warrant a randomized-controlled trial, including cold exposure, of this novel intervention in people with SCI.

The impact of lower-limb function on upper-limb pull and push strength in elite handcycling athletes.

This study investigated the impact of performing a closed kinetic chain with the lower limbs on isometric upper-limb pull and push strength. Sixty-two elite handcyclists were assessed with the Manual Muscle Test and allocated to groups with partial to normal (LLF) or no lower-limb (no-LLF) function. Both groups performed upper-limb strength measurements under two kinetic-chain conditions. During the closed-chain condition, the lower limbs were attached to two footrests, providing horizontal and vertical support. During the open-chain condition, the footrests were removed and the limbs were supported vertically by a horizontal plate. Repeated-measures ANOVA were conducted to investigate main effects (open vs. closed chain, LLF vs. no-LLF) and their interaction. During pull, LLF performed better (p < 0.001, +11%) by pushing against the footrests. However, this increase in pulling strength during a closed-chain condition was not observed in the no-LLF. Therefore, findings suggest an advantage for the least impaired athletes by being able to perform lower-limb closed chains during pulling. Handcyclists with LLF can maximise pulling performance by adjusting the footrests. The classification system should consider the implications of these findings on the allocation of athletes with different levels of LLF and/or on the equipment regulation.

Upper-Body versus Lower-Body Cooling in Individuals with Paraplegia during Arm-Crank Exercise in the Heat.

PURPOSE: For wheelchair users with a spinal cord injury, the lower body may be a more convenient cooling site than the upper body. However, it remains unknown if leg cooling reduces thermal strain in these individuals. We compared the impact of upper-body versus lower-body cooling on physiological and perceptual outcomes during submaximal arm-crank exercise under heat stress in individuals with paraplegia. METHODS: Twelve male participants with paraplegia (T4-L2, 50% complete lesion) performed a maximal exercise test in temperate conditions, and three heat stress tests (32°C, 40% relative humidity) in which they received upper-body cooling (COOL-UB), lower-body cooling (COOL-LB), or no cooling (CON) in a randomized counterbalanced order. Each heat stress test consisted of four exercise blocks of 15 min at 50% of peak power output, with 3 min of rest in between. Cooling was applied using water-perfused pads, with 14.8-m tubing in both COOL-UB and COOL-LB. RESULTS: Gastrointestinal temperature was 0.2°C (95% confidence interval (CI), 0.1°C to 0.3°C) lower during exercise in COOL-UB versus CON (37.5°C ± 0.4°C vs 37.7°C ± 0.3°C, P = 0.009), with no difference between COOL-LB and CON ( P = 1.0). Heart rate was lower in both COOL-UB (-7 bpm; 95% CI, -11 to -3 bpm; P = 0.01) and COOL-LB (-5 bpm; 95% CI, -9 to -1 bpm; P = 0.049) compared with CON. The skin temperature reduction at the cooled skin sites was larger in COOL-LB (-10.8°C ± 1.1°C) than in COOL-UB (-6.7°C ± 1.4°C, P < 0.001), which limited the cooling capacity in COOL-LB. Thermal sensation of the cooled skin sites was improved and overall thermal discomfort was lower in COOL-UB ( P = 0.01 and P = 0.04) but not in COOL-LB ( P = 0.17 and P = 0.59) compared with CON. CONCLUSIONS: Upper-body cooling more effectively reduced thermal strain than lower-body cooling in individuals with paraplegia, as it induced greater thermophysiological and perceptual benefits.

Heat preparedness and exertional heat illness in Paralympic athletes: A Tokyo 2020 survey.

Paralympic athletes may be at increased risk for exertional heat illness (EHI) due to reduced thermoregulatory ability as a consequence of their impairment. This study investigated the occurrence of heat-stress related symptoms and EHI, and the use of heat mitigation strategies in Paralympic athletes, both in relation to the Tokyo 2020 Paralympic Games and previous events. Paralympic athletes competing in Tokyo 2020 were invited to complete an online survey five weeks prior to the Paralympics and up to eight weeks after the Games. 107 athletes (30 [24-38] years, 52% female, 20 nationalities, 21 sports) completed the survey. 57% of respondents had previously experienced heat-stress related symptoms, while 9% had been medically diagnosed with EHI. In Tokyo, 21% experienced at least one heat-stress related symptom, while none reported an EHI. The most common symptom and EHI were, respectively, dizziness and dehydration. In preparation for Tokyo, 58% of respondents used a heat acclimation strategy, most commonly heat acclimatization, which was more than in preparation for previous events (45%; P = 0.007). Cooling strategies were used by 77% of athletes in Tokyo, compared to 66% during past events (P = 0.18). Cold towels and packs were used most commonly. Respondents reported no medically-diagnosed EHIs during the Tokyo 2020 Paralympic Games, despite the hot and humid conditions in the first seven days of competition. Heat acclimation and cooling strategies were used by the majority of athletes, with heat acclimation being adopted more often than for previous competitions.

Sports-Related Health Problems in Para-Sports: A Systematic Review With Quality Assessment.

CONTEXT: Participation in sports is associated with a risk of sports-related health problems. For athletes with an impairment, sports-related health problems further burden an already restricted lifestyle, underlining the importance of prevention strategies in para-sports. OBJECTIVE: To provide a comprehensive overview with quality assessment of the literature on sports-related health problems, their etiology, and available preventive measures in para-sports following the steps of the Sequence of Prevention. DATA SOURCES: A literature search (in PubMed, Embase, SPORTDiscus, CINAHL and the Cochrane Library) was performed up to December 8, 2021, in collaboration with a medical information specialist. STUDY SELECTION: The search yielded 3006 articles, of which 64 met all inclusion criteria. STUDY DESIGN: Systematic review with quality assessment. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Two independent researchers carried out the screening process and quality assessment. One researcher extracted data, and the Sequence of Prevention categorized evidence. RESULTS: A total of 64 studies were included, of which 61 reported on the magnitude and risk factors of sports-related health problems, while only 3 reported on the effectiveness of preventive measures. Of these, 30 studies were of high quality. Most studies (84%) included elite-level athletes. The reported injury incidence varied widely between sports (0-91 per 1000 athlete days) and impairment categories (1-50 per 1000 athlete days). The same applies to illness incidence with regard to different sports (3-49 per 1000 athlete days) and impairment categories (6-14 per 1000 athlete days). CONCLUSION: This review shows the current vast range of reported sport-related health problems in para-sports. There is limited evidence concerning the severity of these sports-related health problems and inconclusive evidence on the risk factors. Lastly, the evidence regarding the development and effectiveness of preventive measures for para-athletes is sparse.

Humid Heat Equally Impairs Maximal Exercise Performance in Elite Para-Athletes and Able-Bodied Athletes.

PURPOSE: This study aimed to compare the impact of hot-humid environmental conditions on performance outcomes, thermoregulatory responses, and thermal perception during exercise between elite para- and able-bodied (AB) athletes. METHODS: Twenty elite para-athletes (para-cycling and wheelchair tennis) and 20 elite AB athletes (road cycling, mountain biking, beach volleyball) performed an incremental exercise test in a temperate environment (mean ± SD, 15.2°C ± 1.2°C; relative humidity, 54% ± 7%) and a hot-humid environment (31.9°C ± 1.6°C, 72% ± 5%). Exercise tests started with a 20-min warm-up at 70% of maximal heart rate, after which power output increased by 5% every 3 min until volitional exhaustion. RESULTS: Time to exhaustion was shorter in hot-humid versus temperate conditions, with equal performance loss for para- and AB athletes (median (interquartile range), 26% (20%-31%) vs 27% (19%-32%); P = 0.80). AB athletes demonstrated larger exercise-induced increases in gastrointestinal temperature (T gi ) in hot-humid versus temperate conditions (2.2 ± 0.7 vs 1.7 ± 0.5, P < 0.001), whereas T gi responses in para-athletes were similar between conditions (1.3 ± 0.6 vs 1.3 ± 0.4, P = 0.74). Para- and AB athletes showed similar elevations in peak skin temperature ( P = 0.94), heart rate ( P = 0.67), and thermal sensation score ( P = 0.64) in hot-humid versus temperate conditions. CONCLUSIONS: Elite para-athletes and AB athletes demonstrated similar performance decrements during exercise in hot-humid versus temperate conditions, whereas T gi elevations were markedly lower in para-athletes. We observed large interindividual variation within both groups, suggesting that in both para- and AB athletes, personalized heat mitigation plans should be developed based on individual thermal testing.

Optimization of Protocols Using Neuromuscular Electrical Stimulation for Paralyzed Lower-Limb Muscles to Increase Energy Expenditure in People With Spinal Cord Injury.

OBJECTIVE: The aim of this study was to evaluate whether using surface neuromuscular electrical stimulation (NMES) for paralyzed lower-limb muscles results in an increase in energy expenditure and whether the number of activated muscles and duty cycle affect the potential increase. DESIGN: This was a cross-sectional study. RESULTS: Energy expenditure during all NMES protocols was significantly higher than the condition without NMES (1.2 ± 0.2 kcal/min), with the highest increase (+51%; +0.7 kcal/min, 95% confidence interval, 0.3-1.2) for the protocol with more muscles activated and the duty cycle with a shorter rest period. A significant decrease in muscle contraction size during NMES was found with a longer stimulation time, more muscles activated, or the duty cycle with a shorter rest period. CONCLUSION: Using NMES for paralyzed lower-limb muscles can significantly increase energy expenditure compared with sitting without NMES, with the highest increase for the protocol with more muscles activated and the duty cycle with a shorter rest period. Muscle fatigue occurred significantly with the more intense NMES protocols, which might cause a lower energy expenditure in a longer protocol. Future studies should further optimize the NMES parameters and investigate the long-term effects of NMES on weight management in people with SCI.

Associations between meeting exercise guidelines, physical fitness, and health in people with spinal cord injury.

PURPOSE: (1) To estimate the proportion of Dutch wheelchair users with spinal cord injury (SCI) who meet different SCI exercise guidelines; (2) to evaluate which demographic and lesion characteristics are associated with meeting these guidelines; (3) whether meeting these guidelines is associated with physical fitness and health. MATERIALS AND METHODS: Based on the PASIPD questionnaire items, participants were allocated to meeting two SCI aerobic exercise guidelines, which differ in exercise load. Differences in personal, lesion, fitness, and health characteristics between groups were tested with a one-way ANOVA. Multiple regression analyses were performed to evaluate if meeting guidelines was associated with better fitness and health. Statistical significance was accepted at p < 0.05. RESULTS: Of the 358 included participants, 63.1% met at least one aerobic exercise guideline. Being female, older age, having tetraplegia, and lower educational level were associated with a lower likelihood to meet the aerobic exercise guidelines. Meeting aerobic exercise guidelines showed a positive association with all respiratory and exercise capacity parameters. Limited associations were found between meeting exercise guidelines and health. CONCLUSIONS: Meeting exercise guidelines was associated with better respiratory functions and exercise capacity with additional fitness and some body composition benefits in higher exercise activity levels.IMPLICATIONS FOR REHABILITATIONMeeting SCI exercise guidelines are associated with better respiratory functions and exercise capacity with additional fitness and body composition benefits when higher exercising at higher activity levels, emphasizing the value and importance of regular exercise in individuals with SCI.

Shoulder muscle activity after latissimus dorsi transfer in an active elevation.

Background: After latissimus dorsi transfer (LDT), an increase in scapulothoracic (ST) contribution in thoracohumeral (TH) elevation is observed when compared to the asymptomatic shoulder. It is not known which shoulder muscles contribute to this change in shoulder kinematics, and whether the timing of muscle recruitment has altered after LDT. The aim of the study was to identify which shoulder muscles and what timing of muscle recruitment are responsible for the increased ST contribution and shoulder elevation after LDT for a massive irreparable posterosuperior rotator cuff tear (MIRT). Methods: Thirteen patients with a preoperative pseudoparalysis and MIRT were recruited after LDT with a minimum follow-up of 1 year. Three-dimensional electromagnetic tracking was used to assess maximum active elevation of the shoulder (MAES) in both the LDT and the asymptomatic contralateral shoulder (ACS). Surface electromyography (EMG) tracked activation (% EMG max) and activation timing of the latissimus dorsi (LD), deltoid, teres major, trapezius (upper, middle and lower) and serratus anterior muscles were collected. MAES was studied in forward flexion, scapular abduction and abduction in the coronal plane. Results: In MAES, no difference in thoracohumeral motion was observed between the LDT and ACS, P = .300. However, the glenohumeral motion for MAES was significantly lower in LDT shoulders F(1,12) = 11.230, P = .006. The LD % EMG max did not differ between the LDT and ACS in MAES. A higher % EMG max was found for the deltoid F(1,12) = 17.241, P = .001, and upper trapezius F(1,10) = 13.612, P = .004 in the LDT shoulder during MAES. The middle trapezius only showed a higher significant difference in % EMG max for scapular abduction, P = .020 (LDT, 52.3 ± 19.4; ACS, 38.1 ± 19.7).The % EMG max of the lower trapezius, serratus anterior and teres major did not show any difference in all movement types between the LDT and ACS and no difference in timing of recruitment of all the shoulder muscles was observed. Conclusions: After LDT in patients with a MIRT and preoperative pseudoparalysis, the LD muscle did not alter its % EMG max during MAES when compared to the ACS. The cranial transfer of the LD tendon with its native %EMG max, together with the increased %EMG max of the deltoid, middle and upper trapezius muscles could be responsible for the increased ST contribution. The increased glenohumeral joint reaction force could in turn increase active elevation after LDT in a previous pseudoparalytic shoulder.

Heat acclimation does not negatively affect salivary immunoglobulin-A and self-reported illness symptoms and wellness in recreational athletes.

Heat acclimation (HA) protocols repeatedly expose individuals to heat stress. As HA is typically performed close to the pinnacle event, it is essential that the protocol does not compromise immune status, health, or wellbeing. The purpose of this study was to examine the effect of HA on resting salivary immunoglobulin-A (s-IgA) and salivary cortisol (s-cortisol), self-reported upper-respiratory tract symptoms, and self-reported wellness parameters. Seventeen participants (peak oxygen uptake 53.2 ± 9.0 mL·kg-1·min-1) completed a 10-day controlled-hyperthermia HA protocol, and a heat stress test both before (HST1) and after (HST2) HA (33°C, 65% relative humidity). Resting saliva samples were collected at HST1, day 3 and 7 of the HA protocol, HST2, and at 5 ± 1 days post-HA. Upper-respiratory tract symptom data were collected weekly from one week prior to HA until three weeks post HA, and wellness ratings were reported daily throughout HA. HA successfully induced physiological adaptations, with a lower end-exercise rectal temperature and heart rate and higher whole-body sweat rate at HST2 compared to HST1. In contrast, resting saliva flow rate, s-IgA concentration, s-cortisol concentration, and s-cortisol secretion rate remained unchanged (n = 11-14, P = 0.10-0.48). Resting s-IgA secretion rate increased by 39% from HST1 to HST2 (n = 14, P = 0.03). No changes were observed in self-reported upper respiratory tract symptoms and wellness ratings. In conclusion, controlled-hyperthermia HA did not negatively affect resting s-IgA and s-cortisol, self-reported upper-respiratory tract symptoms, and self-reported wellness parameters in recreational athletes.

Twelve-Week Daily Gluteal and Hamstring Electrical Stimulation Improves Vascular Structure and Function, Limb Volume, and Sitting Pressure in Spinal Cord Injury: A Pilot Feasibility Study.

OBJECTIVE: We examined the long-term effects of low-intensity electrical stimulation on (micro)vasculature and sitting pressure of a home-based, wearable electrical stimulation device in a pilot feasibility study. DESIGN: In a cohort observation before-after trial, nine middle-aged male (n = 8) and female (n = 1) individuals (48 ± 15 yrs) with American Spinal Injury Association A-C classified chronic (1-24 yrs) spinal cord injury underwent 12 wks of self-administered daily, low-intensity gluteal and hamstring electrical stimulation (50 Hz, 6 hrs [30-min electrical stimulation, 15-min rest]). Common femoral artery diameter and blood blow were determined with ultrasound, skin vascular function during local heating was assessed using Laser-Doppler flowmetry, thigh volume was estimated using leg circumferences and skinfolds, and interface sitting pressure was measured using pressure mapping. RESULTS: Resting common femoral artery diameter increased (0.73 ± 0.20 to 0.79 ± 0.22 cm, P < 0.001) and baseline common femoral artery blood flow increased (0.28 ± 0.12 to 0.40 ± 0.15 l/min, P < 0.002). Gluteal cutaneous vascular conductance showed a time*temperature interaction (P = 0.01) with higher conductance at 42°C after 12 wks. Ischial peak pressure decreased (P = 0.003) by 32 ± 23 mm Hg and pressure gradient decreased (23 ± 7 to 16 ± 6 mm Hg, P = 0.007). Thigh volume increased (+19%, P = 0.01). CONCLUSIONS: Twelve-week daily home-based gluteal and hamstring electrical stimulation is feasible and effective to improve (micro)vasculature and sitting pressure, and electrical stimulation may have clinical implications for ameliorating pressure ulcers and (micro)vascular complications in spinal cord injury.

Lifestyle and health changes in wheelchair users with a chronic disability after 12 weeks of using the WHEELS mHealth application.

PURPOSE: The aim of this study was to determine changes in physical activity, nutrition, sleep behaviour and body composition in wheelchair users with a chronic disability after 12 weeks of using the WHEELS mHealth application (app). METHODS: A 12-week pre-post intervention study was performed, starting with a 1-week control period. Physical activity and sleep behaviour were continuously measured with a Fitbit charge 3. Self-reported nutritional intake, body mass and waist circumference were collected. Pre-post outcomes were compared with a paired-sample t-test or Wilcoxon signed-rank test. Fitbit data were analysed with a mixed model or a panel linear model. Effect sizes were determined and significance was accepted at p < .05. RESULTS: Thirty participants completed the study. No significant changes in physical activity (+1.5 √steps) and sleep quality (-9.7 sleep minutes; -1.2% sleep efficiency) were found. Significant reduction in energy (-1022 kJ, d = 0.71), protein (-8.3 g, d = 0.61) and fat (-13.1 g, d = 0.87) intake, body mass (-2.2 kg, d = 0.61) and waist circumference (-3.3 cm, d = 0.80) were found. CONCLUSION: Positive changes were found in nutritional behaviour and body composition, but not in physical activity and sleep quality. The WHEELS app seems to partly support healthy lifestyle behaviour.Implications for RehabilitationHealthy lifestyle promotion is crucial, especially for wheelchair users as they tend to show poorer lifestyle behaviour despite an increased risk of obesity and comorbidity.The WHEELS lifestyle app seems to be a valuable tool to support healthy nutrition choices and weight loss and to improve body satisfaction, mental health and vitality.

Predicting resting energy expenditure in people with chronic spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The aims of this study were (1) to validate the two recently developed SCI-specific REE equations; (2) to develop new prediction equations to predict REE in a general population with SCI. SETTING: University, the Netherlands. METHODS: Forty-eight community-dwelling men and women with SCI were recruited (age: 18-75 years, time since injury: ≥12 months). Body composition was measured by dual-energy X-ray absorptiometry (DXA), single-frequency bioelectrical impedance analysis (SF-BIA) and skinfold thickness. REE was measured by indirect calorimetry. Personal and lesion characteristics were collected. SCI-specific REE equations by Chun et al. [1] and by Nightingale and Gorgey [2] were validated. New equations for predicting REE were developed using multivariate regression analysis. RESULTS: Prediction equations by Chun et al. [1] and by Nightingale and Gorgey [2] significantly underestimated REE (Chun et al.: -11%; Nightingale and Gorgey: -11%). New equations were developed for predicting REE in the general population of people with SCI using FFM measured by SF-BIA and Goosey-Tolfrey et al. skinfold equation (R2 = 0.45-0.47; SEE = 200 kcal/day). The new equations showed proportional bias (p < 0.001) and wide limits of agreement (LoA, ±23%). CONCLUSIONS: Prediction equations by Chun et al. [1] and by Nightingale and Gorgey [2] significantly underestimated REE and showed large individual variations in a general population with SCI. The newly developed REE equations showed proportional bias and a wide LoA (±23%) which limit the predictive power and accuracy to predict REE in the general population with SCI. Alternative methods for measuring REE need to be investigated.

Association between upper-limb isometric strength and handcycling performance in elite athletes.

This study investigated the association among isometric upper-limb strength of handcyclists and sport-specific performance outcomes. At two international events, 62 athletes were tested on upper-limb strength, measured with an isometric-strength setup and with Manual Muscle Test (MMT). Horizontal force (Fz), effectiveness, rate of development, variability, and asymmetries were calculated for upper-limb pull and push. Performance measures were mean (POmean) and peak (POpeak) 20-s sprint power output and average time-trial velocity (TTvelocity). Regression models were conducted to investigate which pull and push strength variables associated strongest with performance measures. Additional regression analyses were conducted with an MMT sum score as predictor. Push and pull Fz showed the strongest associations with all outcomes. Combined push and pull Fz explained (p < .001) 80-81% of variance of POmean and POpeak. For TTvelocity, only push Fz was included in the model explaining 29% of the variance (p < .001). MMT models revealed weaker associations with sprint PO (R2 = .38-.40, p < .001) and TTvelocity (R2 = .18, p = 0.001). The findings confirmed the relevance of upper-limb strength on handcycling performance and the significance of ratio-scaled strength measures. Isometric strength outcomes are adequate sport-specific indicators of impairment in handcycling classification, but future research should corroborate this notion and its potential to discriminate between sports classes.

Shoulder kinematics and muscle activity following latissimus dorsi transfer for massive irreparable posterosuperior rotator cuff tears in shoulders with pseudoparalysis.

BACKGROUND: The aim of this study was to evaluate the thoracohumeral (TH) and glenohumeral (GH) motion with muscle activity after latissimus dorsi transfer (LDT) in a shoulder with a massive irreparable posterosuperior rotator cuff tear (MIRT) and pseudoparalysis compared with the asymptomatic contralateral shoulder (ACS). METHODS: We recruited and evaluated 13 patients after LDT in a shoulder with preoperative clinical pseudoparalysis and an MIRT on magnetic resonance imaging, with a minimum follow-up period of 1 year, and with a Hamada stage of 3 or less. Three-dimensional electromagnetic tracking was used to assess shoulder active range of motion in both the LDT shoulder and the ACS. The maximal active elevation of the shoulder (MAES) was assessed and consisted of forward flexion, scapular abduction, and abduction in the coronal plane. Maximal active internal rotation and external rotation were assessed separately. Surface electromyography (EMG) was performed to track activation of the latissimus dorsi (LD) and deltoid muscles during shoulder motion. EMG was scaled to its maximal isometric voluntary contraction recorded in specified strength tests. RESULTS: In MAES, TH motion of the LDT shoulder was not significantly different from that of the ACS (F1,12 = 1.174, P = .300) but the GH contribution was significantly lower in the LDT shoulder for all motions (F1,12 = 11.230, P = .006). External rotation was significantly greater in the ACS (26° ± 10° in LDT shoulder vs. 42° ± 11° in ACS, P < .001). The LD percentage EMG maximum showed no significant difference between the LDT shoulder and ACS during MAES (F1,11 = 0.005, P = .946). During maximal active external rotation of the shoulder, the LDT shoulder showed a higher percentage EMG maximum than the ACS (3.0% ± 2.9% for LDT shoulder vs. 1.2% ± 2.0% for ACS, P = .006). CONCLUSIONS: TH motion improved after LDT in an MIRT with pseudoparalysis and was not different from the ACS except for external rotation. However, GH motion was significantly lower after LDT than in the ACS in active-elevation range of motion. The LD was active after LDT but not more than in the ACS except for active external rotation, which we did not consider relevant as the activity did not rise above 3% EMG maximum. The favorable clinical results of LDT do not seem to be related to a change in LD activation and might be explained by its effect in preventing proximal migration of the humeral head in active elevation.

Electrical stimulation to prevent recurring pressure ulcers in individuals with a spinal cord injury compared to usual care: the Spinal Cord Injury PREssure VOLTage (SCI PREVOLT) study protocol.

BACKGROUND: Pressure ulcers (PUs) on the buttocks are among the most common secondary complications in individuals with chronic spinal cord injury (SCI). PUs can result from sitting for extended periods, disuse atrophy, increased sitting pressure and reduced circulation. Compared with usual care, activation of paralysed muscles using electrical stimulation (ES) has been shown to markedly increase paralysed muscle mass, improve circulation of skin and muscle and improve sitting pressure distribution. ES might therefore be a useful method to reduce PU incidence. METHODS: A multicentre randomized controlled trial (SCI PREVOLT) will be conducted with an economic and process evaluation alongside. One hundred participants with a SCI in the chronic phase and a minimal incidence of 1 PU in the last 5 years will be recruited from rehabilitation centres across the Netherlands. Participants will be stratified by centre and age and randomized to the intervention or control group. The intervention group will use ES at least 1 h/day during at least 4 times a week for 1 year next to usual care. The control group will only receive usual care. The primary outcome is the incidence of PUs, measured by a blinded person assessing the presence or absence of a PU on the buttocks on a photo made by the participant or his/her caregiver. The incidence of a PU will be evaluated every 2 weeks. Secondary outcomes include interface pressure distribution, blood flow in the profunda femoris artery, muscle thickness of the hamstrings and gluteal muscles and questionnaires about different dimensions of life, e.g. participation and quality of life. Secondary outcomes will be measured at baseline and 3, 6, 9 and 12 months after randomization. DISCUSSION: This study will assess if electrical stimulation is a (cost-)effective method to prevent PUs and reduce the risk factors of getting PUs. If ES is effective and cost-effective compared with usual care, ES could be implemented in daily treatment of individuals with a SCI. TRIAL REGISTRATION: Netherlands Trials Register NTR NL9469 . Registered on 26 May 2021.

Accuracy of Heart Rate Measurement by the Fitbit Charge 2 During Wheelchair Activities in People With Spinal Cord Injury: Instrument Validation Study.

BACKGROUND: Heart rate (HR) is an important and commonly measured physiological parameter in wearables. HR is often measured at the wrist with the photoplethysmography (PPG) technique, which determines HR based on blood volume changes, and is therefore influenced by blood pressure. In individuals with spinal cord injury (SCI), blood pressure control is often altered and could therefore influence HR accuracy measured by the PPG technique. OBJECTIVE: The objective of this study is to investigate the HR accuracy measured with the PPG technique with a Fitbit Charge 2 (Fitbit Inc) in wheelchair users with SCI, how the activity intensity affects the HR accuracy, and whether this HR accuracy is affected by lesion level. METHODS: The HR of participants with (38/48, 79%) and without (10/48, 21%) SCI was measured during 11 wheelchair activities and a 30-minute strength exercise block. In addition, a 5-minute seated rest period was measured in people with SCI. HR was measured with a Fitbit Charge 2, which was compared with the HR measured by a Polar H7 HR monitor used as a reference device. Participants were grouped into 4 groups-the no SCI group and based on lesion level into the T1 (cervical) group. Mean absolute percentage error (MAPE) and concordance correlation coefficient were determined for each group for each activity type, that is, rest, wheelchair activities, and strength exercise. RESULTS: With an overall MAPEall lesions of 12.99%, the accuracy fell below the standard acceptable MAPE of -10% to +10% with a moderate agreement (concordance correlation coefficient=0.577). The HR accuracy of Fitbit Charge 2 seems to be reduced in those with cervical lesion level in all activities (MAPEno SCI=8.09%; MAPET1=20.43%). The accuracy of the Fitbit Charge 2 decreased with increasing intensity in all lesions (MAPErest=6.5%, MAPEactivity=12.97%, and MAPEstrength=14.2%). CONCLUSIONS: HR measured with the PPG technique showed lower accuracy in people with SCI than in those without SCI. The accuracy was just above the acceptable level in people with paraplegia, whereas in people with tetraplegia, a worse accuracy was found. The accuracy seemed to worsen with increasing intensities. Therefore, high-intensity HR data, especially in people with cervical lesions, should be used with caution.