Incremental Wheelchair Research Articles

Effect of 12-week sports intervention programme on physical fitness and sports performance in individuals with spinal cord injury

Objectives: Inactivity in individuals with spinal cord injury (SCI) results in low physical fitness, cardiopulmonary endurance and poor quality of life. Sports participation is known to enhance physical fitness. Therefore, the present study evaluated effect of a structured, 12-week MGM Sports Intervention for Sports Intervention Program for SCI (SPISI) on physical fitness and throw-ball performance in individuals with SCI. Materials and Methods: The study was conducted at MGM School of Physiotherapy and Spinal Cord Injury Rehabilitation centre in Navi Mumbai, India. Following ethical approval, 15 individuals with SCI (80% males and 20% females mean age 33.1 ± 7.2 years) were recruited. Upper-extremity explosive power (medicine-ball-throw), agility (t-test), cardiorespiratory endurance (incremental shuttle wheelchair propulsion test) and ball-throwing capacity (maximal-pass test) were evaluated pre- and post-12-week sports intervention programme (SPISI). The protocol involved strength training of upper extremity training at 50% 1 repetition maximum and participation in throw-ball sport. Results: Following training, increase in upper extremity explosive power (11%), cardiopulmonary endurance (5%), agility (8%) and ball-throwing capacity in distance (7%) (P < 0.05) was observed. The large effect size was observed for sports performance (maximal-pass test distance-Cohen’s d 1.261), moderate for cardiorespiratory endurance (incremental wheelchair propulsion test distance Cohen’s d 0.517) and upper extremity explosive power (medicine-ball throw distance 0.593). Increment in all outcome variables was greater than minimal clinically important difference. Conclusion: Sports intervention programme (SPISI) for 12 weeks brought about minimal clinically important difference in upper-extremity explosive power, agility, cardiorespiratory endurance and sport-specific performance and should be included as an integral component of rehabilitation of individuals with SCI.

Wheelchair propulsion fatigue thresholds in electromyographic and ventilatory testing.

Qualitative study. The objective of the present study are physiological processes occurring when the intensity of manual wheelchair propulsion approaches levels causing muscular fatigue. In particular, we set out to (1) detect the electromyographic (EMG) and ventilatory fatigue threshold during a single wheelchair incremental test, (2) examine the relationship between EMG threshold (EMGT) and ventilatory threshold (VT), and (3) detect the EMG threshold differences between the propulsive and recovery muscle synergies. Biomechanics laboratory at the University of Alberta, Canada. Oxygen uptake and EMG signals from ten wheelchair users (seven males and three females) were recorded as they were each performing an incremental propulsion bout in their own wheelchairs on a wheelchair ergometer. The V-slope method was used to identify the VT, and the EMGT of each of the eight muscles (anterior deltoid, middle deltoid, posterior deltoid, infraspinatus, upper trapezius, sternal head of pectoralis major, biceps brachii, and triceps brachii) was determined using the bisegmental linear regression method. For each participant, we were able to determine the EMGT and VT from a single incremental wheelchair propulsion bout. EMGT stands in good agreement with VT, and there was a high similarity in EMGT between push and recovery muscles (intraclass correlation coefficient = 0.91). The EMG fatigue threshold method can serve as a valid and reliable tool for identifying the onset of muscular fatigue during wheelchair propulsion, thus providing a foundation for automated muscle fatigue detection/prediction in wearable technology.

Perceived exertion responses to wheelchair propulsion differ between novice able-bodied and trained wheelchair sportspeople

ObjectivesTo investigate peripheral (RPEP) and central (RPEC) Ratings of Perceived Exertion during wheelchair propulsion in untrained able-bodied (AB) participants, and trained wheelchair rugby athletes with and without cervical spinal cord injury (CSCI). DesignCross-sectional study. Methods38 participants (AB: n=20; wheelchair rugby athletes with CSCI: n=9; without CSCI: n=9) completed an incremental wheelchair propulsion test to exhaustion on a motorised treadmill. Gas exchange measures and heart rate (HR) were collected throughout. RPEP and RPEC on the Category Ratio-10 were verbally recorded each minute. Blood lactate concentration ([BLa]) was determined post-test. ResultsBetween 50–100% peak oxygen uptake (V̇O2peak), RPEP was greater than RPEC in AB (p<0.05), but not in athletes with (p=0.07) or without (p=0.16) CSCI. RPEP was greater in AB compared to players with CSCI (Effect sizes: 1.24–1.62), as were respiratory exchange ratio (1.02±0.10 vs 0.82±0.11, p<0.05) and [BLa]peak (7.98±2.53 vs 4.66±1.57mmol·L−1). RPEC was greater in athletes without CSCI compared to those with CSCI (Effect sizes: 0.70–1.38), as were HR (166±20 vs 104±15 beats·min−1, p<0.05) and ventilation (59.2±28.8 vs 35.1±16.6L·min−1, p=0.01). ConclusionsRPEP was dominant over RPEC during wheelchair propulsion for untrained AB participants. For athletes with CSCI, lower RPEP and RPEC were reported at the same %V̇O2peak compared to those without CSCI. The mechanism for this remains to be fully elucidated.

Reliability and minimal detectable change of a new treadmill-based progressive workload incremental test to measure cardiorespiratory fitness in manual wheelchair users

Background: Cardiorespiratory fitness training is commonly provided to manual wheelchair users (MWUs) in rehabilitation and physical activity programs, emphasizing the need for a reliable task-specific incremental wheelchair propulsion test. Objective: Quantifying test-retest reliability and minimal detectable change (MDC) of key cardiorespiratory fitness measures following performance of a newly developed continuous treadmill-based wheelchair propulsion test (WPTTreadmill). Methods: Twenty-five MWUs completed the WPTTreadmill on two separate occasions within one week. During these tests, participants continuously propelled their wheelchair on a motorized treadmill while the exercise intensity was gradually increased every minute until exhaustion by changing the slope and/or speed according to a standardized protocol. Peak oxygen consumption (VO2peak), carbon dioxide production (VCO2peak), respiratory exchange ratio (RERpeak), minute ventilation (VEpeak) and heart rate (HRpeak) were computed. Time to exhaustion (TTE) and number of increments completed were also measured. Intra-class correlation coefficients (ICC) were calculated to determine test-retest reliability. Standard error of measurement (SEM) and MDC90% values were calculated. Results: Excellent test-retest reliability was reached for almost all outcome measures (ICC=0.91-0.76), except for RERpeak (ICC=0.58), which reached good reliability. TTE (ICC=0.89) and number of increments (ICC=0.91) also reached excellent test-retest reliability. For the main outcome measures (VO2peak and TTE), absolute SEM was 2.27 mL/kg/min and 0.76 minutes, respectively and absolute MDC90% was 5.30 mL/kg/min and 1.77 minutes, respectively. Conclusion: The WPTTreadmill is a reliable test to assess cardiorespiratory fitness among MWUs. TTE and number of increments could be used as reliable outcome measures when VO2 measurement is not possible.

The multi-stage fitness test as a predictor of endurance fitness in wheelchair athletes

The aims of this study were two-fold: (1) to consider the criterion-related validity of the multi-stage fitness test (MSFT) by comparing the predicted maximal oxygen uptake ([Vdot]O2max) and distance travelled with peak oxygen uptake ([Vdot]O2peak) measured using a wheelchair ergometer (n = 24); and (2) to assess the reliability of the MSFT in a sub-sample of wheelchair athletes (n = 10) measured on two occasions. Twenty-four trained male wheelchair basketball players (mean age 29 years, s = 6) took part in the study. All participants performed a continuous incremental wheelchair ergometer test to volitional exhaustion to determine [Vdot]O2peak, and the MSFT on an indoor wooden basketball court. Mean ergometer [Vdot]O2peak was 2.66 litres · min−1 (s = 0.49) and peak heart rate was 188 beats · min−1 (s = 10). The group mean MSFT distance travelled was 2056 m (s = 272) and mean peak heart rate was 186 beats · min−1 (s = 11). Low to moderate correlations (ρ = 0.39 to 0.58; 95% confidence interval [CI]: −0.02 to 0.69 and 0.23 to 0.80) were found between distance travelled in the MSFT and different expressions of wheelchair ergometer [Vdot]O2peak. There was a mean bias of −1.9 beats · min−1 (95% CI: −5.9 to 2.0) and standard error of measurement of 6.6 beats · min−1 (95% CI: 5.4 to 8.8) between the ergometer and MSFT peak heart rates. A similar comparison of ergometer and predicted MSFT [Vdot]O2peak values revealed a large mean systematic bias of 15.3 ml · kg−1 · min−1 (95% CI: 13.2 to 17.4) and standard error of measurement of 3.5 ml · kg−1 · min−1 (95% CI: 2.8 to 4.6). Small standard errors of measurement for MSFT distance travelled (86 m; 95% CI: 59 to 157) and MSFT peak heart rate (2.4 beats · min−1; 95% CI: 1.7 to 4.5) suggest that these variables can be measured reliably. The results suggest that the multi-stage fitness test provides reliable data with this population, but does not fully reflect the aerobic capacity of wheelchair athletes directly.

Leistungsphysiologische Parameter und Kenngrößen der muskulären und metabolischen Beanspruchung bei querschnittgelähmten Sportlern mit unterschiedlichen Lähmungshöhen

Summary The physical activity gains importance for humans with a disability in rehabilitation, prevention up to high-performance sports. Parameters like the muscle enzymes creatin kinase (Ck), lactate dehydrogenase (LDH) or urea have become more valuable in sports medical laboratory diagnostics. Until now parameters of muscular or metabolic stress, of acute and chronic overstrain or overtraining states have not been studied sufficiently in spinal cord injured athletes. Athletes with low paraplegia showed significantly higher Ck-concentrations than spinal cord injured persons with high lesion levels. This Ck levels were outside of the normal range. Athletes with tetraplegia or high paraplegia exhibited higher urea values before exercise. The muscle enzymes Ck and LDH increased in all examined groups due to the exhaustive step-wise incremental wheelchair ergometry, while a change of the urea concentration was not found. In all examined groups a leukocyte-stimulating effect of physical exercise could be observed, which was differently pronounced in dependence on the lesion level. Exhaustive incremental wheelchair exercise led to comparable changes in spinal cord injured athletes and in non handicapped control persons. These changes were partly dependent on the lesion level. Therefore it can be assumed that these parameters can be used to evaluate muscular and metabolic stress in spinal cord injured athletes despite the impairment of the peripheral sympathetic system, the smaller innervated muscle mass or the everyday movement in the wheelchair.

The oxygen uptake-heart rate relationship in trained female wheelchair athletes

We examined the relationship between the percentage of peak heart rate (HR) and the percentage of peak oxygen uptake VO2 during steady-rate incremental wheelchair propulsion in 10 trained female wheelchair athletes (WAs) to determine the appropriateness of using American College of Sports Medicine (ACSM) target HRs for training prescription. Oxygen uptake was calculated during each submaximal exercise stage, and HR was monitored continuously. Peak VO2 was determined with the use of a separate protocol. Linear regression equations of percentage of peak HR versus percentage of peak VO2 were measured for each participant. Subsequently, we calculated the percentage of peak HR values corresponding with 40%, 60%, 80%, and 85% peak VO2. The linear regression formula (derived as the group mean of the slope and intercept terms determined from each individual participant) was % peak HR = 0.652 x % peak VO2 + 35.2 (standard error of the estimate [SEE] 3.41). The group mean of the individual correlation coefficients for the VO2-HR relationship was r = 0.973. The percentage peaks of HRs for the WAs were slightly, though not significantly, greater than those suggested by the ACSM across the exercise intensity continuum. These findings suggest that training programs prescribed on the basis of ACSM target HR guidelines need not be altered for trained female WAs with lesions of T6 and below. Notably, the discrepancy between the WA values and the population norm (ACSM) decreased from 6% at 40% peak VO2 (i.e., 61% vs. 55%) to <1% at 85% peak VO2 (i.e., 90.6% vs. 90.0%). This discrepancy indicates a tendency for the use of percentage of HR peak at the lower exercise intensities to slightly underestimate the relative exercise intensity (i.e., percentage of peak VO2) in the WA population.

Time Motion Analysis and Physiological Profile of Canadian World Cup Wheelchair Basketball Players

The purpose of this study was to evaluate the time elite wheelchair basketball players spent performing various game activities during a World Cup game, measure the heart rate response during such activity, and describe the physiological profile of each player participating in the game. Six male members of the Canadian World Cup wheelchair basketball team were videotaped during an entire game to determine the time spent performing seven different categories of activity. Time motion analysis indicated that players spent 8.9% of the game time sprinting, 23.5% gliding, 18.2% contesting for ball possession, 0.6% sprinting with the ball, 0.3% shooting, and 48.3% resting on the bench and floor. Twenty percent (20%) of game time was played at an intensity above the ventilatory threshold. The group mean value for peak oxygen uptake during incremental wheelchair exercise on rollers was 2.60L/min and group mean peak 5 and 30 second anaerobic power development on an arm crank ergometer was 486.3 W and 336.8 W, respectively, suggest that training for and playing elite wheelchair basketball induces significant improvement in these tests of fitness.

Physiological responses during wheelchair racing in quadriplegics and paraplegics.

The purposes of this study were: (1) to compare the physiological responses during simulated wheelchair racing (SR) between male quadriplegics and paraplegics, (2) to test the validity of the SR against a track race (TR) and (3) to examine the relationship between the peak oxygen uptake (peak VO2) and wheeling velocity (WV) during the SR and TR. Seven quadriplegics (C5-8 lesions) and six paraplegics (T5-L4 lesions) completed (1) an incremental wheelchair velocity test, (2) a SR (1.6 km for quadriplegics and 3.2 km for paraplegics), and (3) an indoor TR of the same distance. The subjects performed the incremental velocity test and SR in their personal wheelchairs mounted on a roller system interfaced with customized software programmed to provide velocity and distance feedback. Physiological responses were monitored using an automated metabolic cart and electrocardiogram. Blood lactate concentration [La] was determined from finger prick samples. Peak VO2 and peak heart rate (peak HR) were significantly higher in the paraplegics compared to quadriplegics: 1.90 +/- 0.54 vs 1.07 +/- 0.35 l/min, and 188 +/- 11 beats/min vs 117 +/- 12 beats/min respectively. The paraplegics exercised at significantly (p < 0.05) higher percentages of peak VO2 and peak HR during the SR compared to quadriplegics (95% vs 76% and 95% vs 86%, respectively). No significant relationships (p < 0.05) were observed between the peak VO2 and WV during the SR and TR in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

The maximum physiological responses during incremental wheelchair and arm cranking exercise in male paraplegics

Ten physically active male paraplegics (means = 30 +/- 1 yr), with lesion levels ranging from T5 to L4/S2, underwent two incremental exercise tests to exhaustion. The exercise tests were arm cranking, utilizing an electronically-braked arm cranker, and wheelchair propulsion on a motor-driven treadmill. The subjects were randomly assigned to groups, and the exercise tests were separated by 1 wk. For the first six subjects, during both modes of exercise, VO2, VCO2, R, VE, and heart rates were recorded throughout; for the remaining four subjects the same variables were recorded after the heart rate reached 160 b X min-1. The VO2 (l X min-1 and ml X min-1 X kg-1), VCO2 (l X min-1), HR, and VE BTPS (l X min-1) were significantly higher at the termination of the wheelchair exercise than at the termination of the arm cranking exercise. The minute ventilation, when recorded throughout both exercise tests, showed a relatively linear phase at first, followed by a curvilinear phase. The findings of this study indicate that in the present group of paraplegics, the highest VO2 was obtained during maximum wheelchair exercise.

The effects of prolonged exercise on spinally injured subjects

The effects of prolonged exercise on paraplegics have not been reported. Seven male paraplegic subjects with spinal lesions from T4 - T12 - L1 underwent an incremental wheelchair treadmill test to exhaustion. Heart rate (HR), VO2max, and VESTPD were recorded and calculated. One week later, subjects exercised in their wheelchairs at approximately 50% (mean = 52 +/- 2%) of VO2max for 60 min on a motorized treadmill. Approximately 10 ml venous blood was withdrawn both 10 min and immediately prior to the prolonged exercise, at 20, 40, and 60 min of the exercise period, and at 10 min post-exercise. Venous blood was analyzed for glucose, hemoglobin, lactate, Na+, K+, Cl-, and plasma protein. Hematocrit was recorded and plasma volume changes calculated VO2, VE, and HR were recorded at 17, 37, and 57 min of the prolonged exercise. The mean VO2max was 29.5 +/- 2.7 ml.kg-1.min-1, with a mean max VESTPD and HR of 61.86 +/- 4.98 1.min-1 and 174 +/- 4 b.min-1, respectively. The changes in VO2 and VE during the prolonged wheelchair exercise were not significant. Significant changes occurred in venous lactate and plasma glucose concentrations during prolonged wheelchair exercise. Plasma volume changes were similar to those seen in able-bodied subjects. A notable finding was the pre-exercise hemodilution. Present data indicate that paraplegics can exercise at approximately 50% VO2 for 60 min, producing responses similar to those in able-bodied subjects.