# Laboratory Assessment of Manual Wheelchair Propulsion
###### Abstract
Good technique minimizes energy loss [11] and maximizes forward  
Figure 1: Subsystems of a manual wheelchair (_Freasy_ model, manufactured by Cosmotech, Gliwice, Poland; source: own study). motion [12]. At the same time, experience and adaptation of the muscular system to the specifics of the wheelchair drive system lead to improved performance over time [13; 14]. The design of the wheelchair significantly impacts its drive efficiency [15]. Factors, such as the quality of the dimensional fit of the wheelchair to the user, the rigidity of the frame, the size of the wheels, the type of tires, the cushioning, and the weight of the wheelchair, are essential. These factors are determined by the possibility of customizing the body support system to the user's size, disability, and preferences. Customization options for wheelchairs often include seat height, seat angle, backrest height, and wheel angle relative to the vertical axis (camber) [16]. The backrest height significantly affects wheelchair user well-being. It influences posture, propulsion efficiency, and muscle activation. Adjusting the backrest angle influences the biomechanical efficiency of wheelchair propulsion. A 10-degree recline in the backrest can increase biomechanical efficiency by 10% [17]. The ergonomic design of the backrest should aim to support the spine's natural curvature. A backward adjustable thoracic support helps maintain a neutral pelvic tilt and higher lumbar lordosis, which are beneficial for posture. This adjustment also results in lower back muscle activation, potentially reducing the risk of back pain [18]. Users of ultralight wheelchairs often do not adjust the backrest height when purchasing a new wheelchair. This suggests that user training is needed to maximize the benefits of backrest height fit [19]. A lower backrest height reduces the risk of upper limb injuries in wheelchair users, but it is also important to consider other factors. The choice of backrest height should be tailored to the individual user's needs and preferences [20]. The rear wheel camber significantly affects push force during manual wheelchair propulsion. The push time, angle, and abduction vary between 3 and 6 degrees of camber [21]. However, increased camber angles, such as 15 degrees, lead to higher loading on the upper extremities, increasing the risk of injury despite a larger push-rim effective force [22]. Proper maintenance of a wheelchair also affects the efficiency of the wheelchair propulsion [23]. Keeping all mechanisms in good condition and the tires inflated to the correct pressure has a significant effect on the ease of use of the wheelchair [24]. Some wheelchair users may use devices to assist with manual propulsion, such as gloves with grip-enhancing materials or wheelchair accessories designed to improve performance. Weather conditions, e.g., wind, rain, and temperature, are crucial when analyzing the performance of the wheelchair drive system. Adverse weather conditions make it more challenging to drive a wheelchair. The type of surface and terrain affects performance. Smooth and level surfaces like sidewalks are more accessible to drive on than uneven terrain. Side inclination, uphill, and downhill gradients also affect the power required for propulsion [25]. Therefore, effective manual wheelchair propulsion is a multifaceted issue influenced by a complex interplay of factors encompassing the user's physical capabilities, wheelchair design characteristics, and environmental conditions. Optimizing these factors leads to a more comfortable and less physically demanding wheelchair experience for the user. Emerging methods, described in scientific documents, intended for analyzing and optimizing manual wheelchair drives hold the potential to significantly improve the quality of life for wheelchair users. To substantiate this hypothesis, a comprehensive review and analysis of laboratory methods documented in the scientific literature were conducted to assess their efficiency in evaluating wheelchair propulsion [26].