In the field of sports for the disabled, this last decade has been marked by the development of handcycling. Although assessment of maximal capacity during arm exercises in cases of spinal cord injury (SCI) has been widely investigated, investigations of maximal capacity in handcyclists remain less frequent.
The aim of this study was to investigate the physiological parameters of an incomplete quadriplegic athlete (cervical lesion C5-C6; ASIA-D) during an adapted incremental handcycling test and to judge the appropriateness of the test. Using such a test, it will then be possible to determine the individualized training program intensity needed to improve the athlete’s aerobic capacity.
The athlete completed an incremental hand cycling test (i.e., an adapted Léger-Boucher test), with the handbike mounted on an ergotrainer. The athlete’s physiological parameters were recorded during the test, and the pedalling rate and the perceived exertion rate were estimated. Given the athlete’s pathology, ergonomic adaptations were necessary in order to improve comfort and propulsion quality.
The maximum values recorded ( ˙VO2peakV˙O2peak
V ˙ O 2peak
= 1.16 l/min; [La] = 7.7 mmol/l; heart rate peak = 133 beats/min; maximum respiratory frequency = 85 cycles/min and averaged pedaling rate = 95 tours/min) indicate that the incremental test, adapted for handcycling, is maximal, and consequently, it should be possible to individualize the training intensity.
This test is innovative and potentially applicable in a booming discipline garnering more and more interest. However, first it is necessary to extend this test to a larger population and to test the extended application in field.
Dans le domaine de la pratique handisport, cette dernière décennie a été marquée par le développement de la pratique du handbike . Bien que l’évaluation des capacités maximales à l’exercice à bras des personnes blessées médullaires ait été largement réalisée, celle des athlètes handbikers demeure moins fréquente.
L’objectif de cette étude est d’évaluer les paramètres physiologiques d’un athlète blessé médullaire ayant une lésion incomplète de grade D (classification ASIA) au niveau de la cinquième vertèbre cervicale au cours d’un test d’effort incrémental adapté sur handbike et d’estimer l’applicabilité de celui-ci aux handbikers en général et de cette classe en particulier. À partir d’un tel test, il sera alors possible de déterminer une intensité de travail personnalisée en vue d’optimiser l’aptitude aérobie.
L’athlète a réalisé un test d’effort incrémental en handbike – test Léger-Boucher adapté – sur home-trainer. Les variables physiologiques ont été enregistrées au cours du test. La cadence de manivellage ainsi que la perception de l’effort ont aussi été estimées. Compte tenu de la pathologie de l’athlète, afin d’améliorer le confort et la qualité de propulsion, des adaptations ergonomiques du handbike ont été nécessaires.
Les valeurs maximales relevées ( ˙VO2picV˙O2pic
V ˙ O 2pic
= 1,16 l/min, [La] = 7,7 mmol/l, FC pic = 133 batt/min, fréquence respiratoire maximale = 85 cycles/min et fréquence moyenne de manivellage = 95 tours/min) tendent à montrer que le test incrémental adapté pour le handbike est maximal. Par conséquent, il permettrait d’individualiser une intensité de travail.
Cette étude préliminaire tend à montrer que ce test pourrait être utilisable pour mieux individualiser l’entraînement de ces athlètes à la condition cependant qu’elle soit confirmée par une étude sur une population plus importante et réalisée sur le terrain.
Physical capacity in cases of spinal cord injury (SCI) is assessed during upper body exercise using either an arm crank or a wheelchair ergometer. The heterogeneity of field and laboratory tests, of protocol methods (continuous/discontinuous with variable intensity and workload) and of participant positioning not only demonstrates the influence of test conditions on exercise responses, but also the interest in this subject. Nevertheless, despite the interest, only a few authors have published studies involving quadriplegics, and most of them used arm-cranks or wheelchair ergometers .
Jansen et al. have stated that daily wheelchair use is not enough to improve physical capacity. Using a wheelchair imposes great physical constraints, which can decrease the quality of life and autonomy of quadriplegics. It is therefore necessary to engage in regular physical exercise, implementing an individualized training program with an innovative means of locomotion, such as a handbike. Though handbike use has expanded over the last decade in the wheelchair user community, including quadriplegics, it is still hardly used in scientific research . Handbike propulsion is considered to have a better mechanical efficiency than handrim wheelchair propulsion since the physiological responses are less important for an equivalent power output .
Our study investigated the physiological responses during a maximal handcycling test in an incomplete quadriplegic athlete (ASIA-D). The participant had a high handcycling level (more than 15 hours a week) and was preparing for a long trip through the Pyrenees (650 km in 20 days, including 16 hills). Given his level, this athlete was more representative of handcyclists than class D quadriplegics. Using his personal handbike during the study made it possible to reproduce real conditions of locomotion, involving the proper muscle mass. The adaptation of a maximal test for handcycling represented the major interest of this study. Since we adapted the Léger-Boucher Test (LBT), we called it the Adapted Léger-Boucher Test (ALBT) . In our study, we examined the maximal physiological responses with the objective of individualizing the intensity of the training program to improve aerobic capacity. Our results can be applied both in the field of sports for the disabled and rehabilitation.
Material and methods
A young incomplete quadriplegic, who used a handrim wheelchair as his daily means of locomotion, volunteered to participate in the study. Before he gave his informed consent, all testing procedures were explained verbally. After he gave his consent, the procedures were conducted under medical supervision. The experimental procedures were approved by a local ethics committee and complied with the ethical standards of the 1975 Helsinki Declaration.
The athlete was male, 30 years of age, weighed 63 kg and measured 1.82 m. Fourteen years prior to this study, he injured his spinal cord at the cervical level resulting in an incomplete lesion at the fifth cervical vertebrae (C5). He was assessed as class D on the Asia Impairment Scale. He has practiced handcycling for 4 years. His main motor functions were hampered as following:
grasping movement impossible in hands;
functional limitation in both forearms;
grade 3 triceps (according to manual muscle testing);
non-functional obliquus, transversus abdominis and latissimus dorsi on the right side;
non-functional pectoralis minor on both sides.
This study was carried out on the athlete’s own handbike (Sopur spirit 470), adapted for his particular motor functions, which was mounted on a roller ergometer (model TACX 1450 Speedmatic), as shown in Fig. 1 . The athlete sat in a semi-recumbent position, which did not allow complete elbow extension when the back and the shoulders were pressed against the backrest, arms held out, and hands on the cranks. This sitting position situated the crank axis slightly below the scapulohumeral joint. Abdominal strap was not used since athlete never used it during training and did not wish to use it for his trip through the Pyrenees, thus similar conditions were maintained.
The ALBT is an adaptation from the well-known LBT. Created by Léger and Boucher in 1980, the LBT was initially used for runners. The ALBT uses an identical audiotape to the one used in LBT, which emits “beep” sounds at regular intervals. However, increments were changed from 1 km/h to 1.6 km/h, making each stage correspond to a specific speed.
This study was conducted in laboratory setting, using a roller ergometer set at the minimal resistance level and for which drag forces were not measurable. The ALBT was applied starting at 12.8 km/h. Speed was controlled using a speedometer attached to the handbike. The test was considered finished when the participant reached exhaustion, or when participant was unable to maintain required speed more than three times. The last completed stage indicated maximal aerobic velocity. A 3-minute warm-up period (corresponding to the literature average ) and a 6-minute recovery phase (3 min active/ 3 min passive) were imposed, respectively before and after testing.
During testing, participant wore a nose-clip and breathed into a mouthpiece with low dead space; oxygen consumption ( ˙VO2V˙O2
V ˙ O 2
, in l/min), ventilation ( ˙VEV˙E
V ˙ E
, in l/min), tidal volume ( V t , in l) and respiratory exchange ratio (RER) were recorded continuously using open-circuit system (Ergocard ® ). Data were analyzed by computer, averaging ˙VO2V˙O2
V ˙ O 2
V ˙ E
values every 30 seconds using appropriate software. Additionally, the heart rate (HR) was monitored with an electrocardiogram, and lactate concentration was measured at the ear lobe (after warming the sampling zone to arterialize the blood). The athlete was encouraged to continue as long as he could in order to reach a ˙VO2V˙O2
V ˙ O 2
Crank rate and rate of perceived exertion (RPE)
At each stage, the freely-chosen crank rate was visually estimated by counting revolutions per 30 seconds and then averaging for 1 minute (revolutions per minute [rpm]). At the end of the test, the athlete also estimated his muscle and dyspnea perceptions using the 10-degree Borg scale .
Table 1 summarizes the measured variables (metabolic, cardiac, ventilatory and clinic exertion), allowing us to see to what extent the test was maximal. We observed a very high maximal respiratory frequency (85 cycles/min) as well a high freely-chosen crank rate (95 rpm). Maximal aerobic velocity was estimated at 36.8 km/h. The analysis of the ˙VO2V˙O2
V ˙ O 2
curve ( Fig. 2 ) demonstrated the absence of a ˙VO2V˙O2
V ˙ O 2
plateau, which, according to Rimaud et al. , is normally considered to be a criterion for maximality.
|Criteria for assessing maximal tests||Results|
V ˙ O 2max
V ˙ O 2max
V ˙ O 2peak
= 1.16 l/min
|[La] > 8 mmol/l||[La] = 7.7 mmol/l (end of the test)|
|FC max > 85% theoretical FC max a||FC peak a = 133 beats/min|
|RER> 1.1 [gas exchange ratio ( ˙VCOV˙CO|
V ˙ CO
V ˙ O 2
|RER = 1.34|
|Perceived exertion rate (Borg) [max if n > 5]||Dyspnea = 7|
|Muscular = 8|
|Maximal respiratory frequency||85 cycles/min|
|Average crank rate||≈ 95 tours/min|
|Last sustained stage||No. 16 (MAV = 36.8 km/h)|