Peak power output in handcycling of individuals with a chronic spinal cord injury: predictive modeling, validation and reference values

Changes in body satisfaction during and after a 5-month handcycle training period and associations with physical capacity and body composition in individuals with a physical impairment

PURPOSE

To investigate: (1) changes in body satisfaction during five months of handcycle training and one year after the training period; (2) whether longitudinal changes are dependent on sex, waist circumference and severity of the physical impairment; (3) associations between changes in physical capacity or body composition, and body satisfaction.

MATERIALS AND METHODS

Individuals (N = 143) with health conditions such as spinal cord injury filled out the Adult Body Satisfaction Questionnaire: at the start of the training (T1), directly after the training period (T2); and four months (T3) and one year after the training period (T4). At T1 and T2, physical capacity was determined with an upper-body graded exercise test, and waist circumference was measured. Handcycling classification was used as a proxy for the severity of impairment.

RESULTS

Multilevel regression analyses showed that body satisfaction significantly increased during the training period and significantly decreased back to pre-training levels at follow-up. Individuals with more severe impairments showed a larger decrease at T4. Improvements in physical capacity and waist circumference were significantly associated with improvements in body satisfaction.

CONCLUSIONS

Body satisfaction significantly increased during the training period, but significantly decreased during follow-up. Additional efforts might be necessary to keep individuals engaged in long-term exercise.

Exercise and aerobic capacity in individuals with spinal cord injury: A systematic review with meta-analysis and meta-regression

BACKGROUND

A low level of cardiorespiratory fitness [CRF; defined as peak oxygen uptake ([Formula: see text]O2peak) or peak power output (PPO)] is a widely reported consequence of spinal cord injury (SCI) and a major risk factor associated with chronic disease. However, CRF can be modified by exercise. This systematic review with meta-analysis and meta-regression aimed to assess whether certain SCI characteristics and/or specific exercise considerations are moderators of changes in CRF.

METHODS AND FINDINGS

Databases (MEDLINE, EMBASE, CENTRAL, and Web of Science) were searched from inception to March 2023. A primary meta-analysis was conducted including randomised controlled trials (RCTs; exercise interventions lasting >2 weeks relative to control groups). A secondary meta-analysis pooled independent exercise interventions >2 weeks from longitudinal pre-post and RCT studies to explore whether subgroup differences in injury characteristics and/or exercise intervention parameters explained CRF changes. Further analyses included cohort, cross-sectional, and observational study designs. Outcome measures of interest were absolute (A[Formula: see text]O2peak) or relative [Formula: see text]O2peak (R[Formula: see text]O2peak), and/or PPO. Bias/quality was assessed via The Cochrane Risk of Bias 2 and the National Institute of Health Quality Assessment Tools. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random effects models were used in all meta-analyses and meta-regressions. Of 21,020 identified records, 120 studies comprising 29 RCTs, 67 pre-post studies, 11 cohort, 7 cross-sectional, and 6 observational studies were included. The primary meta-analysis revealed significant improvements in A[Formula: see text]O2peak [0.16 (0.07, 0.25) L/min], R[Formula: see text]O2peak [2.9 (1.8, 3.9) mL/kg/min], and PPO [9 (5, 14) W] with exercise, relative to controls (p < 0.001). Ninety-six studies (117 independent exercise interventions comprising 1,331 adults with SCI) were included in the secondary, pooled meta-analysis which demonstrated significant increases in A[Formula: see text]O2peak [0.22 (0.17, 0.26) L/min], R[Formula: see text]O2peak [2.8 (2.2, 3.3) mL/kg/min], and PPO [11 (9, 13) W] (p < 0.001) following exercise interventions. There were subgroup differences for R[Formula: see text]O2peak based on exercise modality (p = 0.002) and intervention length (p = 0.01), but there were no differences for A[Formula: see text]O2peak. There were subgroup differences (p ≤ 0.018) for PPO based on time since injury, neurological level of injury, exercise modality, and frequency. The meta-regression found that studies with a higher mean age of participants were associated with smaller changes in A[Formula: see text]O2peak and R[Formula: see text]O2peak (p < 0.10). GRADE indicated a moderate level of certainty in the estimated effect for R[Formula: see text]O2peak, but low levels for A[Formula: see text]O2peak and PPO. This review may be limited by the small number of RCTs, which prevented a subgroup analysis within this specific study design.

CONCLUSIONS

Our primary meta-analysis confirms that performing exercise >2 weeks results in significant improvements to A[Formula: see text]O2peak, R[Formula: see text]O2peak, and PPO in individuals with SCI. The pooled meta-analysis subgroup comparisons identified that exercise interventions lasting up to 12 weeks yield the greatest change in R[Formula: see text]O2peak. Upper-body aerobic exercise and resistance training also appear the most effective at improving R[Formula: see text]O2peak and PPO. Furthermore, acutely injured, individuals with paraplegia, exercising for ≥3 sessions/week will likely experience the greatest change in PPO. Ageing seemingly diminishes the adaptive CRF responses to exercise training in individuals with SCI.

REGISTRATION

PROSPERO: CRD42018104342.

Reference Values and Cutoff Scores of the Spinal Cord Independence Measure III to Determine Independence for Wheelchair Users and Ambulatory Individuals With Spinal Cord Injury

OBJECTIVE

To establish the reference values and optimal cutoff scores of the Spinal Cord Independence Measure Version III (SCIM III) to indicate independence of wheelchair users (WU) and ambulatory (AM) individuals with spinal cord injury (SCI).

DESIGN

A cross-sectional study.

SETTING

Tertiary rehabilitation center and communities.

PARTICIPANTS

A total of 309 (168 WU and 141 AM) participants with SCI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

SCIM III scores.

RESULTS

Participants with greater levels of independence had significantly higher SCIM III scores, both total and subitem scores (P<.05). The SCIM III scores of ≥55 and ≥75 were optimal indicators of modified independence in WU and AM individuals, respectively (sensitivity and specificity >93%, AUC>.95). In addition, scores of 90 were proved to be excellent indicators for independence of AM individuals (sensitivity 94%, specificity 100%, AUC=.99).

CONCLUSIONS

The present findings provide the reference values of SCIM III scores covering WU and AM individuals with SCI at various levels of independence as well as optimal cutoff scores to indicate independence of these individuals. These data can be used as standard criteria for data comparison with patients' ability, and target functional values for individuals with SCI in clinical-, community-, and home-based settings.

Steering Does Affect Biophysical Responses in Asynchronous, but Not Synchronous Submaximal Handcycle Ergometry in Able-Bodied Men

Real-life daily handcycling requires combined propulsion and steering to control the front wheel. Today, the handcycle cranks are mostly mounted synchronously unlike the early handcycle generations. Alternatively, arm cycle ergometers do not require steering and the cranks are mostly positioned asynchronously. The current study aims to evaluate the effects of combining propulsion and steering requirements on synchronous and asynchronous submaximal handcycle ergometry. We hypothesize that asynchronous handcycling with steering results in the mechanically least efficient condition, due to compensation for unwanted rotations that are not seen in synchronous handcycling, regardless of steering. Sixteen able-bodied male novices volunteered in this lab-based experiment. The set-up consisted of a handcycle ergometer with 3D force sensors at each crank that also allows “natural” steering. Four submaximal steady-state (60 rpm, ~35 W) exercise conditions were presented in a counterbalanced order: synchronous with a fixed steering axis, synchronous with steering, asynchronous with a fixed axis and asynchronous with steering. All participants practiced 3 × 4 mins with 30 mins rest in between every condition. Finally, they did handcycle for 4 mins in each of the four conditions, interspaced with 10 mins rest, while metabolic outcomes, kinetics and kinematics of the ergometer were recorded. The additional steering component did not influence velocity, torque and power production during synchronous handcycling and therefore resulted in an equal metabolically efficient handcycling configuration compared to the fixed condition. Contrarily, asynchronous handcycling with steering requirements showed a reduced mechanical efficiency, as velocity around the steering axis increased and torque and power production were less effective. Based on the torque production around the crank and steering axes, neuromuscular compensation strategies seem necessary to prevent steering movements in the asynchronous mode. To practice or test real-life daily synchronous handcycling, a synchronous crank set-up of the ergometer is advised, as exercise performance in terms of mechanical efficiency, metabolic strain, and torque production is independent of steering requirements in that mode. Asynchronous handcycling or arm ergometry demands a different handcycle technique in terms of torque production and results in higher metabolic responses than synchronous handcycling, making it unsuitable for testing.

The Course of Physical Capacity in Wheelchair Users During Training for the HandbikeBattle and at 1-Yr Follow-up

OBJECTIVE

The aims of this study were (1) to compare physical capacity at 1-yr follow-up with physical capacity before and after the training period for the HandbikeBattle event and (2) to identify determinants of the course of physical capacity during follow-up.

DESIGN

This was a prospective observational study. Former rehabilitation patients (N = 33) with health conditions such as spinal cord injury or amputation were included. A handcycling/arm crank graded exercise test was performed before (January, T1) and after the training period (June, T2) and at 1-yr follow-up (June, T4). Outcomes were peak power output (W) and peak oxygen uptake (L/min). Determinants were sex (male/female); age (years); classification; physical capacity, musculoskeletal pain, exercise stage of change, and exercise self-efficacy at T1; and HandbikeBattle participation at T4.

RESULTS

Multilevel regression analyses showed that peak power output and peak oxygen uptake increased during the training period and did not significantly change during follow-up (T1: 112 ± 37 W, 1.70 ± 0.48 L/min; T2: 130 ± 40 W, 2.07 ± 0.59 L/min; T4: 126 ± 42 W, 2.00 ± 0.57 L/min). Participants who competed again in the HandbikeBattle showed slight improvement in physical capacity during follow-up, whereas participants who did not compete again showed a decrease.

CONCLUSION

Physical capacity showed an increase during the training period and remained stable after 1-yr follow-up. Being (repeatedly) committed to a challenge might facilitate long-term exercise maintenance.

Effects of 7-week Resistance Training on Handcycle Performance in Able-bodied Males

The effect of an upper body resistance training program on maximal and submaximal handcycling performance in able-bodied males was explored. Eighteen able-bodied men were randomly assigned to a training group (TG: n=10) and a control group (CG: n=8). TG received 7 weeks of upper body resistance training (60% of 1 repetition maximum (1RM), 3×10 repetitions, 6 exercise stations, 2 times per week). CG received no training. Peak values for oxygen uptake (V˙O_2peak), power output (PO_peak), heart rate (HR_peak), minute ventilation (V˙O_Epeak) and respiratory exchange ratio (RER_peak), submaximal values (HR, V˙O₂, RER, PO, and gross mechanical efficiency (GE)), and time to exhaustion (TTE) were determined in an incremental test pre- and post-training. Maximal isokinetic arm strength and 1RM tests were conducted. Ratings of perceived exertion (RPE) were assessed. A two-way repeated measures ANOVA and post-hoc comparisons were performed to examine the effect of time, group and its interaction (p<0.05). TG improved on PO_peak (8.55%), TTE (10.73%), and 1RM (12.28-38.98%). RPE at the same stage during pre- and post-test was lower during the post-test (8.17%). Despite no improvements in V˙O_2peak, training improved PO_peak, muscular strength, and TTE. Upper body resistance training has the potential to improve handcycling performance.

Training for the HandbikeBattle: an explorative analysis of training load and handcycling physical capacity in recreationally active wheelchair users

PURPOSE

(1) to analyze training characteristics of recreationally active wheelchair users during handcycle training, and (2) to examine the associations between training load and change in physical capacity.

METHODS

Former rehabilitation patients (N = 60) with health conditions such as spinal cord injury or amputation were included. Participants trained for five months. A handcycling/arm crank graded exercise test was performed before and after the training period. Outcomes: peak power output per kg (POpeak/kg) and peak oxygen uptake per kg (VO₂peak/kg). Training load was defined as Training Impulse (TRIMP), which is rating of perceived exertion (sRPE) multiplied by duration of the session, in arbitrary units (AU). Training intensity distribution (TID) was also determined (time in zone 1, RPE ≤4; zone 2, RPE 5-6; zone 3, RPE ≥7).

RESULTS

Multilevel regression analyses showed that TRIMP_sRPE was not significantly associated with change in physical capacity. Time in zone 2 (RPE 5-6) was significantly associated with ΔVO₂peak, %ΔVO₂peak, ΔVO₂peak/kg and %ΔVO₂peak/kg.

CONCLUSION

Training at RPE 5-6 was the only determinant that was significantly associated with improvement in physical capacity. Additional controlled studies are necessary to demonstrate causality and gather more information about its usefulness, and optimal handcycle training regimes for recreationally active wheelchair users.IMPLICATIONS FOR REHABILITATIONMonitoring of handcycle training load is important to structure the training effort and intensity over time and to eventually optimize performance capacity. This is especially important for relatively untrained wheelchair users, who have a low physical capacity and a high risk of overuse injuries and shoulder pain.Training load can be easily calculated by multiplying the intensity of the training (RPE 0-10) with the duration of the training in minutes.Results on handcycle training at RPE 5-6 intensity in recreationally active wheelchair users suggests to be promising and should be further investigated with controlled studies.

Physiological responses during simulated 16 km recumbent handcycling time trial and determinants of performance in trained handcyclists

Purpose

To characterise the physiological profiles of trained handcyclists, during recumbent handcycling, to describe the physiological responses during a 16 km time trial (TT) and to identify the determinants of this TT performance.

Methods

Eleven male handcyclists performed a sub-maximal and maximal incremental exercise test in their recumbent handbike, attached to a Cyclus II ergometer. A physiological profile, including peak aerobic power output (PO_Peak), peak rate of oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}$$\end{document}V˙O_2Peak), aerobic lactate threshold (AeLT) and PO at 4 mmol L⁻¹ (PO₄), were determined. Participants also completed a 16 km simulated TT using the same experimental set-up. Determinants of TT performance were identified using stepwise multiple linear regression analysis.

Results

Mean values of PO_Peak = 252 ± 9 W, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}$$\end{document}V˙O_2Peak = 3.30 ± 0.36 L min⁻¹ (47.0 ± 6.8 mL kg⁻¹ min⁻¹), AeLT = 87 ± 13 W and PO₄ = 154 ± 14 W were recorded. The TT was completed in 29:21 ± 0:59 min:s at an intensity equivalent to 69 ± 4% PO_Peak and 87 ± 5% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}$$\end{document}V˙O_2Peak. PO_Peak (r = − 0.77, P = 0.006), PO₄ (r = − 0.77, P = 0.006) and AeLT (r = − 0.68, P = 0.022) were significantly correlated with TT performance. PO₄ and PO_Peak were identified as the best predictors of TT performance (r = 0.89, P < 0.001).

Conclusion

PO_Peak, PO₄ and AeLT are important physiological TT performance determinants in trained handcyclists, differentiating between superior and inferior performance, whereas \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}$$\end{document}V˙O_2peak was not. The TT took place at an intensity corresponding to 69% PO_Peak and 87% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}$$\end{document}V˙O_2peak.

Assessment of Exercise Stroke Volume and Its Prediction From Oxygen Pulse in Paralympic Athletes With Locomotor Impairments: Cardiac Long-Term Adaptations Are Possible

The determinants of cardiac output (CO) during exercise, i.e., stroke volume (SV) and heart rate (HR), could differ in Paralympic athletes (PAthl) with spinal cord injury (SCI) with respect to PAthl with locomotor impairments caused by different health conditions (HCs). The purposes of the present study were the comparisons of two groups of PAthl, one with SCI and the other with either amputation (AMP) or post poliomyelitis syndrome (PM), assessing the (1) peak cardiorespiratory responses and determinants (SV and HR) of CO during maximal and submaximal arm cranking exercise (ACE), respectively; (2) correlations between peak oxygen uptake (VO_2peak) and the highest SV obtained during submaximal exercise; and (3) correlations between oxygen pulse (O₂ pulse, ratio between VO₂ and HR) and both SV and O₂ arterio-venous difference [(a-v)O₂diff]. Each athlete (19 PAthl with SCI, 9 with AMP, and 5 with PM) completed a continuous incremental cardiopulmonary ACE test to volitional fatigue to assess peak responses. In a different session, CO was indirectly measured through carbon dioxide (CO₂) rebreathing method at sub-maximal exercise intensities approximating 30, 50, and 70% of the VO_2peak. There were no significant differences between the PAthl groups in age, anthropometry, and VO_2peak. However, peak HR was significantly lower, and peak O₂ pulse was significantly higher in PAthl with AMP/PM compared to those with SCI. During sub-maximal exercise, PAthl with AMP/PM displayed significantly higher SV values (154.8 ± 17.60 ml) than PAthl with SCI (117.1 ± 24.66 ml). SV correlated significantly with VO_2peak in both PAthl with SCI (R ² = 0.796) and AMP/PM (R ² = 0.824). O₂ pulse correlated significantly with SV in both PAthl with SCI (R ² = 0.888) and AMP/PM (R ² = 0.932) and in the overall sample (R ² = 0.896). No significant correlations were observed between O₂ pulse and (a-v)O₂diff. It was concluded that in PAthl with different HCs: (1) significant differences, as a consequence of the different HC, exist in the determinants of CO at maximal and submaximal ACE; (2) SV is a significant determinant of VO_2peak, suggesting cardiac adaptations possible also in PAthl with SCI; and (3) SV can be predicted from O₂ pulse measurements during submaximal exercise in both groups of PAthl.

Crank fore-aft position alters the distribution of work over the push and pull phase during synchronous recumbent handcycling of able-bodied participants

Objective

The objective of the current study was to investigate the effect of four different crank fore-aft positions on elbow flexion and shoulder protraction, the consequent propulsion kinetics and the physiological responses during handcycling.

Methods

Twelve able-bodied male participants volunteered in this study. Crank fore-aft positions were standardised at 94%, 97%, 100% and 103% of the participants’ arm length. Two submaximal 3 min trials were performed at a fixed cadence (70 rpm), in a recumbent handcyle attached to an ergometer at two fixed power outputs (30W and 60W). Elbow flexion, shoulder protraction, propulsion kinetics and physiological responses of the participants were continuously measured.

Results

As crank fore-aft distance increased, a decrease in elbow flexion (42±4, 37±3, 33±3, 29±3°) and an increase shoulder protraction was observed (29±5, 31±5, 34±5, 36±5°). The percentage of work done in the pull phase increased as well (62±7, 65±7, 67±6, 69±8%, at 60W), which was in line with an increased peak torque during the pull phase (8.8±1.6, 9.0±1.4, 9.4±1.5, 9.7±1.4Nm, at 60W) and reduced peak torque during the push phase (6.0±0.9, 5.6±0.9,5.6±0.9, 5.4±1.0Nm, in 60W condition). Despite these changes in work distribution, there were no significant changes in gross mechanical efficiency (15.7±0.8, 16.2±1.1, 15.8±0.9, 15.6±1.0%, at 60W). The same patterns were observed in the 30W condition.

Conclusions

From a biomechanical perspective the crank position closest to the trunk (94%) seems to be advantageous, because it evens the load over the push and pull phase, which reduces speed fluctuations, without causing an increase in whole body energy expenditure and hence a decrease of gross mechanical efficiency. These findings may help handcyclists to optimize their recumbent handcycle configuration.

Good association between sprint power and aerobic peak power during asynchronuous arm-crank exercise in people with spinal cord injury

PURPOSE

To (1) investigate the association between sprint power and aerobic power output (POpeak_GXT) during a graded peak exercise test (GXT); and (2) validate the prediction models of POpeak_GXT based on sprint power and personal and lesion characteristics.

MATERIALS AND METHODS

Wheelchair users with tetraplegia (N = 35) and paraplegia (N = 58) performed a 30 s-Wingate test and GXT on an asynchronous arm-crank ergometer. Data were split into samples to develop and validate the model. Sprint power (POmean_Wingate and POpeak_Wingate, respectively) and POpeak_GXT were determined. Regression analyses were performed to develop POpeak_GXT prediction models. Candidate independent variables included POmean_Wingate or POpeak_Wingate, age (years), sex, body mass (kg) or BMI (kg/m²), time since injury (TSI, years) and lesion level (tetraplegia/paraplegia). The best model was validated by comparing the predicted POpeak_GXT with measured POpeak_GXT.

RESULTS

The best model (R ² = 0.76) to predict POpeak_GXT included POmean_Wingate, BMI and all other independent variables. No significant difference was found between measured (68 ± 35 W) and predicted POpeak_GXT (68 ± 30 W, p = 0.97). The ICC was excellent (0.89 with 95% confidence intervals: 0.75-0.95). The 95% limits of agreement for the Bland-Altman plots were wide (-30 to 31 W).

CONCLUSIONS

Strong associations were found between POmean_Wingate and POpeak_GXT. Although relative agreement was excellent, absolute agreement was low. Implications for rehabilitation There is a strong relationship between peak aerobic power output and sprint power output, both tested on an arm-crank ergometer, in people with spinal cord injury. A prediction model for peak aerobic power output, based on sprint power output and personal and lesion characteristics, showed a high explained variance. The predictive model can give a guideline for choosing the right graded exercise test protocol but should be used with caution.

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.