Effects of hand cycle training on wheelchair capacity during clinical rehabilitation in persons with a spinal cord injury

Oxygen uptake and heart rate responses to 4 weeks of RPE-guided handcycle training

PURPOSE

To investigate the efficacy of using Ratings of Perceived Exertion (RPE) to prescribe and regulate a 4-week handcycle training intervention.

METHODS

Thirty active adults, untrained in upper body endurance exercise, were divided into three groups to complete a 4-week intervention: (i) RPE-guided training (n = 10; 2 female), (ii) power output (PO)-guided (n = 10; 2 female) training, or (iii) non-training control (n = 10; 4 female). Training groups performed three sessions of handcycling each week. Oxygen uptake ([Formula: see text]), heart rate (HR), and Feeling Scale (FS) rating were collected during training sessions. RPE-guided training was performed at RPE 13. PO-guided training was matched for percentage of peak PO per session, based upon that achieved by the RPE-guided training group.

RESULTS

There were no differences in percentage of peak [Formula: see text] (66 ± 13% vs 61 ± 9%, p = 0.22), peak HR (75 ± 8% vs 71 ± 6%, p = 0.11) or FS rating (1.2 ± 1.9 vs 0.8 ± 1.6, p = 0.48) between RPE- and PO-guided training, respectively. The average coefficient of variation in percentage of peak HR between consecutive training sessions was 2.8% during RPE-guided training, and 3.4% during PO-guided training.

CONCLUSION

Moderate-vigorous intensity handcycling exercise can be prescribed effectively using RPE across a chronic training intervention, suggesting utility for practitioners in a variety of rehabilitation settings.

Physical Activity and the Health of Wheelchair Users: A Systematic Review in Multiple Sclerosis, Cerebral Palsy, and Spinal Cord Injury

OBJECTIVE

To understand the benefits and harms of physical activity in people who may require a wheelchair with a focus on people with multiple sclerosis (MS), cerebral palsy (CP), and spinal cord injury (SCI).

DATA SOURCES

Searches were conducted in MEDLINE, Cumulative Index to Nursing and Allied Health, PsycINFO, Cochrane CENTRAL, and Embase (January 2008 through November 2020).

STUDY SELECTION

Randomized controlled trials, nonrandomized trials, and cohort studies of observed physical activity (at least 10 sessions on 10 days) in participants with MS, CP, and SCI.

DATA EXTRACTION

We conducted dual data abstraction, quality assessment, and strength of evidence. Measures of physical functioning are reported individually where sufficient data exist and grouped as "function" where data are scant.

DATA SYNTHESIS

No studies provided evidence for prevention of cardiovascular conditions, development of diabetes, or obesity. Among 168 included studies, 44% enrolled participants with MS (38% CP, 18% SCI). Studies in MS found walking ability may be improved with treadmill training and multimodal exercises; function may be improved with treadmill, balance exercises, and motion gaming; balance is likely improved with balance exercises and may be improved with aquatic exercises, robot-assisted gait training (RAGT), motion gaming, and multimodal exercises; activities of daily living (ADL), female sexual function, and spasticity may be improved with aquatic therapy; sleep may be improved with aerobic exercises and aerobic fitness with multimodal exercises. In CP, balance may be improved with hippotherapy and motion gaming; function may be improved with cycling, treadmill, and hippotherapy. In SCI, ADL may be improved with RAGT.

CONCLUSIONS

Depending on population and type of exercise, physical activity was associated with improvements in walking, function, balance, depression, sleep, ADL, spasticity, female sexual function, and aerobic capacity. Few harms of physical activity were reported in studies. Future studies are needed to address evidence gaps and to confirm findings.

Adaptive Admittance Control Scheme with Virtual Reality Interaction for Robot-Assisted Lower Limb Strength Training

Muscle weakness is the primary impairment causing mobility difficulty among stroke survivors. Millions of people are unable to live normally because of mobility difficulty every year. Strength training is an effective method to improve lower extremity ability but is limited by the shortage of medical staff. Thus, this paper proposes a robot-assisted active training (RAAT) by an adaptive admittance control scheme with virtual reality interaction (AACVRI). AACVRI consists of a stiffness variable admittance controller, an adaptive controller, and virtual reality (VR) interactions. In order to provide human-robot reality interactions corresponding to virtual scenes, an admittance control law with variable stiffness term was developed to define the mechanics property of the end effector. The adaptive controller improves tracking performances by compensating interaction forces and dynamics model deviations. A virtual training environment including action following, event feedback, and competition mechanism is utilized for improving boring training experience and engaging users to maintain active state in cycling training. To verify controller performances and the feasibility of RAAT, experiments were conducted with eight subjects. Admittance control provides desired variable interactions along the trajectory. The robot responds to different virtual events by changing admittance parameters according to trigger feedbacks. Adaptive control ensures tracking errors at a low level. Subjects were maintained in active state during this strength training. Their physiological signals significantly increased, and interaction forces were at a high level. RAAT is a feasible approach for lower limb strength training, and users can independently complete high-quality active strength training under RAAT.

The Effect of Adaptive Sports on Individuals with Acquired Neurological Disabilities and Its Role in Rehabilitation: A Systematic Review

The aims of this systematic review were to report on the feasibility of adaptive sports for individuals with acquired central neurological lesion; to analyze the effects of this approach according to the domains of the International Classification of Functioning, Health and Disability (ICF); and to emit guiding points for future research. Two authors searched PubMed, Scopus, Cochrane, Pedro, and SPORTdiscus for eligible trials. Data concerning demographics, outcome measures, results, and conclusions were extracted, and a qualitative synthesis was performed. Adaptive sports seem to be a feasible, efficient, and cost-effective complement to conventional rehabilitation. Significant effects were found on all domains of the ICF, except "environmental factors." Key factors, such as intervention volume, intensity, and type, play a determining role. This review is the first to expose the beneficial effects of adaptive sports practice among individuals with neurological lesions by relying on prospective evidence.

Interrater and intrarater reliability of ventilatory thresholds determined in individuals with spinal cord injury

STUDY DESIGN

Cross-sectional.

OBJECTIVES

Individualized training regimes are often based on ventilatory thresholds (VTs). The objectives were to study: (1) whether VTs during arm ergometry could be determined in individuals with spinal cord injury (SCI), (2) the intrarater and interrater reliability of VT determination.

SETTING

University research laboratory.

METHODS

Thirty graded arm crank ergometry exercise tests with 1-min increments of recreationally active individuals (tetraplegia (N = 11), paraplegia (N = 19)) were assessed. Two sports physicians assessed all tests blinded, randomly, in two sessions, for VT1 and VT2, resulting in 240 possible VTs. Power output (PO), heart rate (HR), and oxygen uptake (VO₂) at each VT were compared between sessions or raters using paired samples t-tests, Wilcoxon signed-rank tests, intraclass correlation coefficients (ICC, relative agreement), and Bland-Altman plots (random error, absolute agreement).

RESULTS

Of the 240 VTs, 217 (90%) could be determined. Of the 23 undetermined VTs, 2 (9%) were VT1 and 21 (91%) were VT2; 7 (30%) among individuals with paraplegia, and 16 (70%) among individuals with tetraplegia. For the successfully determined VTs, there were no systematic differences between sessions or raters. Intrarater and interrater ICCs for PO, HR, and VO₂ at each VT were high to very high (0.82-1.00). Random error was small to large within raters, and large between raters.

CONCLUSIONS

For VTs that could be determined, relative agreement was high to very high, absolute agreement varied. For some individuals, often with tetraplegia, VT determination was not possible, thus other methods should be considered to prescribe exercise intensity.

Different cadences and resistances in sub-maximal synchronous handcycling in able-bodied men: Effects on efficiency and force application

BACKGROUND

With the introduction of an add-on handcycle, a crank system that can be placed in front of a wheelchair, handcycling was made widely available for daily life. With it, people go into town more easily, e.g. to do groceries; meet up with friends, etc. They have more independency and can be socially active. Our aim is to explore some settings of the handcycle, so that it can be optimally used as a transportation device. Therefore, the effects of cadence and added resistance on gross mechanical efficiency and force application during sub-maximal synchronous handcycling were investigated. We hypothesized that a cadence of 52 rpm with a higher resistance (35 W) would lead to a higher gross mechanical efficiency and a more tangential force application than a higher cadence of 70 rpm and no extra resistance (15 W).

METHODS

Twelve able-bodied men rode in an instrumented add-on handcycle on a motorized level treadmill at 1.94 m/s. They performed three sessions of three four-minute blocks of steady state exercise. Gear (70, 60 and 52 rpm) was changed in-between the blocks and resistance (rolling resistance +0 W, +10 W, +20 W) was changed across sessions, both in a counterbalanced order. 3D force production, oxygen uptake and heart rate were measured continuously. Gross mechanical efficiency (ME) and fraction of effective force (FEF) were calculated as main outcomes. The effects of cadence and resistance were analyzed using a repeated measures ANOVA (P<0.05) with Bonferroni-corrected post-hoc pairwise comparisons.

RESULTS

With a decrease in cadence a slight increase in ME (70 rpm: 5.5 (0.2)%, 60 rpm: 5.7 (0.2)%, 52 rpm: 5.8 (0.2)%, P = 0.008, η2p = 0.38), while an increase in FEF (70 rpm: 58.0 (3.2)%, 60 rpm: 66.0 (2.8)%, 52 rpm: 71.3 (2.3)%, P<0.001, η2p = 0.79) is seen simultaneously. Also with an increase in resistance an increase in ME (+0 W: 4.0 (0.2)%, +10 W: 6.0 (0.3)%, +20 W: 7.0 (0.2)%, P<0.001, η2p = 0.92) and FEF (+0 W: 59.0 (2.9)%, +10 W: 66.1 (3.4)%, +20 W: 70.2 (2.4)%, P<0.001, η2p = 0.56) was found.

INTERPRETATION

A cadence of 52 rpm against a higher resistance of about 35 W leads to a more optimal direction of forces and is more mechanically efficient than propelling at a higher cadence or lower resistance. Therefore, changing gears on a handcycle is important, and it is advised to keep the linear hand velocity relatively low for locomotion purposes.

The effects of a home-based arm ergometry exercise programme on physical fitness, fatigue and activity in Polio survivors: a randomised controlled trial

Objective:

To investigate the effect of an eight-week home-based arm ergometry aerobic exercise programme on physical fitness, fatigue, activity and quality of life in Polio Survivors.

Design:

An assessor blinded randomised controlled trial.

Setting:

Home-based exercise.

Subjects:

Fifty-five Polio survivors randomised to exercise or control groups.

Intervention:

Home-based arm ergometry at an intensity of 50%-70% maximum heart rate, compared with usual physiotherapy care.

Main measures:

The Six-minute Arm Test, Fatigue Severity Scale, Physical Activity Scale for Individuals with Physical Disabilities and SF-36. Assessments were completed at baseline and at eight weeks.

Results:

There was no significant difference in the primary outcome, exercising heart rate during the Six-minute Arm Test, between the groups at follow-up [97.6 (SD10.1) compared to 102.4 (SD13.7) beats per minute ( P=0.20)]. Blood pressure was significantly lower in the intervention group at follow-up [systolic blood pressure 132(18.6)mmHg compared to 144.1(14.6)mmHg ( P=0.002)]. There were no between group differences in the Fatigue Severity Scale ( P=0.25) or Physical Activity Scale for Individuals with Physical Disabilities ( P=0.49), with a small difference in SF-36 physical component score ( P=0.04).

Conclusions:

This home-based arm ergometry programme successfully facilitated aerobic exercise in Polio Survivors, but did not result in a significant change in physical fitness, measured by the Six-minute Arm Test.

Handcycling: training effects of a specific dose of upper body endurance training in females

PURPOSE

This study aims to evaluate a handcycling training protocol based on ACSM guidelines in a well-controlled laboratory setting. Training responses of a specific dose of handcycling training were quantified in a homogeneous female subject population to obtain a more in depth understanding of physiological mechanisms underlying adaptations in upper body training.

METHODS

22 female able-bodied participants were randomly divided in a training (T) and control group (C). T received 7-weeks of handcycling training, 3 × 30 min/week at 65 % heart rate reserve (HRR). An incremental handcycling test was used to determine local, exercise-specific adaptations. An incremental cycling test was performed to determine non-exercise-specific central/cardiovascular adaptations. Peak oxygen uptake (peakVO2), heart rate (peakHR) and power output (peakPO) were compared between T and C before and after training.

RESULTS

T completed the training sessions at 65 ± 3 % HRR, at increasing power output (59.4 ± 8.2 to 69.5 ± 8.9 W) over the training program. T improved on handcycling peakVO2 (+18.1 %), peakPO (+31.9 %), and peakHR (+4.0 %). No improvements were found in cycling parameters.

CONCLUSION

Handcycling training led to local, exercise-specific improvements in upper body parameters. Results could provide input for the design of effective evidence-based training programs specifically aimed at upper body endurance exercise in females.

Cardiac acceleration at the onset of exercise: a potential parameter for monitoring progress during physical training in sports and rehabilitation

There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were searched to retrieve studies investigating HRonset. In total 652 studies were retrieved. These articles were then classified as having emphasis on HRonset in a sports or rehabilitation setting, which resulted in 8 of 112 studies with a sports application and 6 of 68 studies with a rehabilitation application that met inclusion criteria. Two co-existing mechanisms underlie HRonset: feedforward (central command) and feedback (mechanoreflex, metaboreflex, baroreflex) control. A number of studies investigated HRonset during the first few seconds of exercise (HRonsetshort), in which central command and the mechanoreflex determine vagal withdrawal, the major mechanism by which heart rate (HR) increases. In subsequent sports and rehabilitation studies, interest focused on HRonset during dynamic exercise over a longer period of time (HRonsetlong). Central command, mechanoreflexes, baroreflexes, and possibly metaboreflexes contribute to HRonset during the first seconds and minutes of exercise, which in turn leads to further vagal withdrawal and an increase in sympathetic activity. HRonset has been described as the increase in HR compared with resting state (delta HR) or by exponential modeling, with measurement intervals ranging from 0-4 s up to 2 min. Delta HR was used to evaluate HRonsetshort over the first 4 s of exercise, as well as for analyzing HRonsetlong. In exponential modeling, the HR response to dynamic exercise is biphasic, consisting of fast (parasympathetic, 0-10 s) and slow (sympathetic, 1-4 min) components. Although available studies differed largely in measurement protocols, cross-sectional and longitudinal training studies showed that studies analyzing HRonset in relation to physical training primarily incorporated HRonsetlong. HRonsetlong slowed in athletes as well as in patients with a coronary disease, who have a relatively fast HRonsetlong. It is advised to include both HRonsetlong and HRonsetshort in further studies. The findings of this review suggest that HRonset is a potential tool for monitoring and titrating training in sports as well as in rehabilitation settings, particularly in patients with ventricular fibrillation. Monitoring HRonset in the early phase of training can help optimize the effectiveness of training and therapy. More research is needed to gain a better understanding of the mechanisms underlying HRonset in relation to their application in sports and rehabilitation settings.

Adverse events in cardiovascular-related training programs in people with spinal cord injury: a systematic review

CONTEXT

There are anecdotal reports of adverse events (AEs) associated with exercise in people with spinal cord injury (SCI) and consequent concern by people with SCI and their providers about potential risks of exercise. Enumeration of specific events has never been performed and the extent of risk of exercise to people with SCI is not understood.

OBJECTIVE

To systematically review published evidence to identify and enumerate reports of adverse events or AEs associated with training in persons with SCI.

METHODS

Review was limited to peer-reviewed studies published in English from 1970 to 2011: (1) in adults with SCI, (2) evaluating training protocols consisting of repeated sessions over at least 4 weeks to maintain or improve cardiovascular health, (3) including volitional exercise modalities and functional electrical stimulation (FES)-enhanced exercise modalities, and (4) including a specific statement about AEs. Trained reviewers initially identified a total of 145 studies. After further screening, 38 studies were included in the review. Quality of evidence was evaluated using established procedures.

RESULTS

There were no serious AEs reported. There were no common AEs reported across most types of interventions, except for musculoskeletal AEs related to FES walking. There were few AEs in volitional exercise studies.

CONCLUSION

There is no evidence to suggest that cardiovascular exercise done according to guidelines and established safety precautions is harmful. To improve the strength of these conclusions, future publications should include definition of AEs, information about pre-intervention screening, and statements of the nature and extent of AEs.

Mountain time trial in handcycling: exercise intensity and predictors of race time in people with spinal cord injury

STUDY DESIGN

Cross-sectional analyses.

OBJECTIVES

To analyze exercise intensity during a mountain time trial in handcycling and to determine predictors of race time.

SETTING

Eight Dutch rehabilitation centers and Austrian mountain.

METHODS

Forty participants with spinal cord injury (SCI; high lesion level (>T6): N=11; low lesion level (⩽T6): N=29) handcycled a 20.2-km mountain time trial. Heart rate (HR) was monitored in 17 (high: N=5, low: N=12) participants during the race to determine exercise intensity, expressed relative to the heart rate reserve (%HRR). Two weeks before the race all participants completed laboratory tests to measure anthropometrics and peak values for power output (POpeak), oxygen uptake (VO2peak) and HR.

RESULTS

Mean race time was 4 h and 1 min (s.d.: 1 h and 24 min), with no difference in race time between lesion groups. Mean exercise intensity during the race was 70±7%HRR. Exercise was mainly (73% of the race time) at a vigorous intensity (60-89%HRR), with 29% of the total time in the 80-89%HRR zone. No clear differences were found in exercise intensities between lesion groups. The strongest predictors for better race times were higher mean %HRR during race (R(2)=57%), lower waist circumference (R(2)=39%), higher POpeak (R(2)=39%) and VO2peak (R(2)=32%).

CONCLUSION

A 20-km mountain time trial in a handcycle is intensive. Faster race times were achieved by those with a lower waist circumference, greater fitness level and ability to perform at higher average exercise intensities during the race. Level of SCI was not significantly associated with race time.

Coordinating arms and legs on a hybrid rehabilitation tricycle: the metabolic benefit of asymmetrical compared to symmetrical arm movements

PURPOSE

The most commonly used propulsion method for handcycling is moving the arms symmetrically. Previous studies indicated that during outdoor handcycling symmetrical arm movements are more efficient. During locomotor movements, however, arm movements are performed asymmetrically in combination with leg movements. We questioned which combination of arm and leg movements is more efficient during combined arm and leg cycling for stationary use.

METHODS

Twenty-five able-bodied adults performed eight submaximal tests of 6 min on a hybrid handcycle at three incremental gears during four different conditions ('arms only' and 'arms & legs' with arms symmetrical and asymmetrical). Oxygen uptake (VO2), heart rate (HR) and Borg score (Borg) were assessed.

RESULTS

Increasing workload resulted in significant increases in VO2 (16 W: 13.0 ± 2.4 ml kg(-1) min(-1), 31 W: 14.5 ± 2.9, 49 W: 15.5 ± 2.8; p < 0.001) and Borg (16 W: 7.7 ± 1.7 points, 31 W: 8.6 ± 1.9, 49 W: 9.5 ± 1.9; p < 0.001). During 'arms only', no differences were found in exercise intensity between symmetrical and asymmetrical movements. Contrarily, during 'arms & legs', both VO2 (p < 0.001) and Borg (p = 0.001) were significantly lower for the asymmetrical (VO2: 13.8 ± 2.6 ml kg(-1) min(-1), Borg: 8.1 ± 1.6 points) compared to the symmetrical condition (VO2: 14.9 ± 2.8, Borg: 9.1 ± 2.0).

CONCLUSIONS

Results indicated that asymmetrical arm movements, especially in combination with leg movements, represented the most efficient condition on a stationary hybrid handcycle. The current results suggest that neural energy costs are lower when moving in the preferred (asymmetrical) coordination when no steering is required. These findings may have implications for stationary arm & leg cycling rehabilitation and tricycle adaptations in patients with spinal cord injury.

Physical strain of handcycling: an evaluation using training guidelines for a healthy lifestyle as defined by the American College of Sports Medicine

OBJECTIVE

Developments in assistive technology such as handcycling provide attractive possibilities to pursue a healthy lifestyle for patients with spinal cord injury. The objective of the study is to evaluate physical stress and strain of handcycling against training guidelines as defined by the American College of Sports Medicine (ACSM).

DESIGN

Seven able-bodied males conducted an incremental peak exercise handcycling test on a treadmill. In addition, two indoor treadmill (1.3 m/second with an inclination of 0.7% and 1.0 m/second with an inclination of 4.8%) and three outdoor over ground exercise bouts were performed (1.7, 3.3, and 5.0 m/second). One individual handcycled a representative 8-km-distance outdoors.

OUTCOME MEASURES

Physical stress and strain were described in terms of absolute and relative power output, oxygen uptake (VO2), gross efficiency (GE), and heart rate (HR). Also, local perceived discomfort (LPD) was determined.

RESULTS

Relative handcycling exercise intensities varied between 23.3 ± 4.2 (below the ACSM lower limit of 46%VO2peak) and 72.5 ± 15.1%VO2peak (well above the ACSM lower limit), with GE ranging from 6.0 ± 1.5% at the lower to 13.0 ± 2.6% at the higher exercise intensities. Exercise intensities were performed at 49.8 ± 4.2 to 80.1 ± 10.5%HRpeak. LPD scores were low to moderate (<27 ± 7).

CONCLUSION

Handcycling is relatively efficient and exercise intensities > 46%VO2peak were elicited. However, exercise load seems to be underestimated using %HRpeak. LPD was not perceived as limiting. Physiological stress and strain in able-bodied individuals appear to be comparable to individuals with a paraplegia. To understand individualize and optimize upper-body training, different training programs must be evaluated.

Effectiveness of aerobic physical training for treatment of chronic asymptomatic bacteriuria in subjects with spinal cord injury: a randomized controlled trial

Objective:

To evaluate the effectiveness and safety of aerobic physical training for treatment of chronic asymptomatic bacteriuria in subjects with spinal cord injury.

Design:

Randomized controlled trial.

Setting:

University hospital.

Subjects:

Forty-two participants with spinal cord injury between C8 and T12 segments were randomly assigned to intervention or control groups.

Intervention:

In the intervention group, subjects received a risk evaluation, stress test and urinary culture before the start of the study and after 16 weeks. The study consisted of aerobic physical conditioning with moderate intensity for the intervention group while the control group was asked to maintain their daily life activities.

Main measures:

Increase of estimated peak oxygen consumption and also if there was a decrease in the proportions of positive urinary culture.

Results:

The intervention group showed an increase of estimated peak oxygen consumption of between 939 (714–1215) and 1154 (1005–1351) mL/min ( P = 0.009) and a reduction of chronic asymptomatic bacteria of between 52.3% (29.8–74.3%) and 14.2% (3–36.3%) ( P < 0.001). No adverse effects related to physical activity were recorded during the period of training.

Conclusion:

The regular practice of physical activity of moderate intensity applied to patients with spinal cord injury may be an effective and safe method for the treatment of chronic asymptomatic bacteriuria.

Development of a motor driven rowing machine with automatic functional electrical stimulation controller for individuals with paraplegia; a preliminary study

Objective

To examine the cardiorespiratory responses of patients with spinal cord injury (SCI) paraplegia using a motor driven rowing machine.

Method

Ten SCI patients with paraplegia [A (n=6), B (n=1), and C (n=3) by the American Spinal Injury Association impairment scale] were selected. Two rowing techniques were used. The first used a fixed seat with rowing achieved using only upper extremity movement (fixed rowing). The second used an automatically moving seat, facilitating active upper extremity movement and passive lower extremity movement via the motorized seat (motor rowing). Each patient performed two randomly assigned rowing exercise stress tests 1-3 days apart. The work rate (WR), time, respiratory exchange ratio (R), oxygen consumption (VO₂), heart rate (HR), metabolic equivalents (METs), and rating of perceived exertion (RPE) were recorded.

Results

WR, time, VO₂, and METs were significantly higher after the motor rowing test than after fixed motor rowing test (p<0.05). HR after motor rowing was significantly lower than fixed rowing (p<0.05).

Conclusion

Cardiorespiratory responses as VO₂, HR and METs can be elicited by the motor rowing for people with paraplegic SCI.

Shoulder load during handcycling at different incline and speed conditions

BACKGROUND

The manual wheelchair user population experiences a high prevalence of upper-limb injuries, which are related to a high load on the shoulder joint during activities of daily living, such as handrim wheelchair propulsion. An alternative mode of propulsion is handcycling, where lower external forces are suggested to be applied to reach the same power output as in handrim wheelchair propulsion. This study aimed to quantify glenohumeral contact forces and muscle forces during handcycling and compare them to previous results of handrim wheelchair propulsion.

METHODS

Ten able-bodied men propelled the handbike on a treadmill at two inclines (1% and 4% with a velocity of 1.66 m/s) and two speed conditions (1.39 and 1.94 m/s with fixed power output). Three-dimensional kinematics and kinetics were obtained and used as input for a musculoskeletal model of the arm and shoulder. Output variables were glenohumeral contact forces and forces of important shoulder muscles.

FINDINGS

The highest mean and peak glenohumeral contact forces occurred at 4% incline (420 N, 890 N respectively). The scapular part of the deltoideus, the triceps and the trapezius produced the highest force.

INTERPRETATION

Due to the circular movement and the continuous force application during handcycling, the glenohumeral contact forces, as well as the muscle forces were clearly lower compared to the results in the existing literature on wheelchair propulsion. These findings prove the assumption that handcycling is mechanically less straining than handrim wheelchair propulsion, which may help preventing overuse to the shoulder complex.