Physical Conditioning and Wheelchair Propulsion
Physical capacity is important to the development of wheelchair propulsion performance. Five articles have explored the relationship between physical conditioning and capacity, and wheelchair propulsion.
Discussion
Kilkens et al. (2005) investigated the longitudinal changes in manual wheelchair skill performance and parameters for physical capacity of people with SCI at the beginning of their inpatient rehabilitation, at three months and at point of discharge. The wheelchair circuit consisted of eight standardized tasks in a fixed sequence on a treadmill, hard and soft surface. The physical capacity parameters included upper extremity muscle strength, peak oxygen uptake and peak power output (PO peak). Their study found a significant relationship between upper extremity strength and PO peak as parameters of physical capacity that influence wheelchair propulsion performance during inpatient rehabilitation of individuals with SCI.
Dallmeijer et al. (2005) tracked 132 participants across eight SCI rehabilitation centres to describe the changes that occurred in relation to wheelchair propulsion capacity (WPC) from the start of rehabilitation, three months post and at discharge. An overall improvement of 45% in WPC, as measured by Maximum Power Output (POmax) was found over the full course of rehabilitation, with significantly higher POmax being noted for participants with incomplete lesions, participants who were younger, and participants who were male. The authors suggest that these findings can help guide clinical intervention related to WPC, individualizing intervention based on these characteristics. However, the course of intervention related to WPC during rehabilitation was not described; it is unclear if there was a standard approach to intervention.
deGroot et al. 2007 examined mechanical efficiency (ME) of wheelchair propulsion, of people with SCI at the start of their rehabilitation, three months post, at discharge and one year post discharge. They are hypothesizing that higher mechanical efficiency, which they attributed to an improved propulsion technique, would show higher peak power outputs (POpeak), better performance times and lower percentage heart rate reserve (%HHR). They found that ME was significantly related to wheelchair propulsion capacity as measured by POpeak, and to the performance time of two wheelchair performance tasks, during rehabilitation and one year post discharge. The authors attributed the higher ME indirectly to propulsion technique, but no data was presented related to participants’ propulsion technique.
Rodgers et al. (2001) hypothesized that a program which combines stretching and strengthening of the muscles critical to propulsion as well as aerobic training would result in more efficient wheelchair propulsion. The supervised training program was completed three times per week for six weeks. Pre and post testing found the only significant wheelchair kinetic change was the propulsive moment, which represented a 14% improvement. The authors suggest that this finding in conjunction with the lack of change noted in the hand rim peak forces and a significant decrease in stroke frequency indicate biomechanical efficiency was improved without increasing stresses on the upper extremity joints. The authors suggest that the findings of significant increases in three kinematic measures (shoulder flexion/extension, maximum elbow extension and trunk flexion) can augment propulsion, especially at times of fatigue.
Qi et al. (2015) explored the relationship between perceived rate of exertion and physical capacity during typical mobility activities. Eleven people with a spinal cord injury level lower than T6 completed propulsion testing on a treadmill in their own wheelchairs, at three specified rates of speed which the authors equated to three different mobility activities; a self-selected comfortable speed at 1ms equated to the minimal safe speed to cross a street with traffic lights, 1.3 ms equated to typical able bodied walking speed, and 1.6ms equated to the upper limit of a self-selected speed. A final test of propulsion was completed using the first test speed with increasing resistance until exhaustion. The authors found that most participants chose a propulsion speed of 1.1 ms as a comfortable speed, which corresponded to approximately 53% VO2peak and an average heart rate of 104 beats per minute (0.69% HRmax). They also found that there were no significant differences between the rate of perceived exertion for respiration and arm. The authors indicate these findings suggest that self-selected propulsion speeds of low and moderate rates, which correspond to typical daily life mobility activities, can provide cardiovascular conditioning.
In their random control study, Gauthier et al. (2018) compared the feasibility, safety and preliminary effectiveness of home-based high intensity interval training (HIIT) and moderate intensity continuous training (MICT) programs in people with spinal cord injury who use manual wheelchairs. Despite the absence of statistically significant cardiovascular and upper extremities strength changes, subjective improvements in general health, including cardiorespiratory fitness were reported by participants. All participants indicated they would recommend their program to others with SCI. The authors noted statistically significant improvements in VO2peak in two individuals in the MICT group who were not regularly exercising prior to the training. They suggested that training could have the biggest impact in sedentary participants as it was the least active individuals at baseline who showed the greatest improvements in UE muscle strength. One participant in the HIIT group dropped out due to shoulder pain and another reported a significant increase. The authors determined that both training programs were feasible and safe in the community but the influence of their weekly follow up calls on participantion in the training was not evaluated. The authors did highlight that programs should be individualized and attention paid to the potential development of shoulder pain with a HIIT, especially in participants with pre-existing shoulder pain.
van der Scheer et al. (2016) investigated the effects a of twice a week, low-intensity wheelchair training program with inactive individuals who had been living with spinal cord injury greater than ten years, to determine if improved cardiovascular and propulsion outcomes could be achieved. In, the results of this randomized control study showed no significant training effects between the exercise and the control group in any of the measures. The authors concluded that this dosage of exercise is insufficient for substantial improvements in an inactive population with long-term SCI. However, it was queried whether outcomesof this study have been influenced by a relative decline in the control group due to drop outs. It is suggested that further research is needed to generalize these outcomes to the broader population.
Torhaug et al. (2016) investigated the effect of maximal bench press strength training on wheelchair propulsion work economy (WE), with individuals with paraplegia. The authors reported that participants in the intervention group (n=9) demonstrated a 17.3% improvement in WE during wheelchair ergometry, as indicated by a reduction in in VO2 consumption. However, there were no changes in the other outcome measures (pulmonary ventilation or respiratory exchange ratio). The authors suggest that based on these results, a strength training regime of high load and few repetitions can lead to improved mobilization force during the concentric phase of wheelchair propulsion, and, despite no endurance-training component to the intervention, result in lower oxygen cost and more efficient wheelchair work economy. Two participants withdrew from the study because of shoulder pain. The authors recommend beginning the training at a lower intensity in those with any latent shoulder disease, however the outcomes of this suggested change were not tested inthis study. Due to the small number of participants, that dropouts occurred due to shoulder pain, and 1 of the 3 otucomes measured changed, it is felt that caution is needed in extrapolating these findings t the larger population.
Conclusions
There is level 2 evidence (from 1 cohort study by Kilkens et al. 2005; from one prospective controlled study by Torhaug et al. 2016; from three pre-post study by deGroot et al. 2007; Rodgers et al. 2001; Dallmeijer et al. 2005) that exercise training at physical capacity and upper extremity strengthening influence wheelchair propulsion performance.
There is level 1b evidence (from 1 RCT: van der Scheer et al. 2016) that twice weekly, low intensity wheelchair propulsion training is not adequate to affect fitness, however there is level 4 evidence (from one pre-post study; Qi et al. 2015) suggesting that manual wheelchair propulsion at low (1ms) and moderate (1.3ms) propulsion rates during typical daily life mobility activities contribute to cardiovascular conditioning.
There is level 2 evidence (from 1 RCT: Gauthier et al. 2018) evidence that community-based programs are feasible and safe training programs for manual wheelchair users.
