# Laboratory Assessment of Manual Wheelchair Propulsion
## 4 Summary and Conclusions  
Analysis of the scientific literature reveals that laboratory methods for measuring wheelchair propulsion can be broadly categorized into two primary approaches: wheelchair dynamometer-based and biomechanical analysis. The wheelchair dynamometer-based methods analyze propulsion efficiency, total muscle effort, power output during propulsion cycles, and energy expenditure. Biomechanical analysis methods assess body position and posture, joint angles, muscle activity, center of mass (COM) changes, and the trajectory of wheelchair movement during propulsion. While real-world propulsion measurement has various methodological limitations, wheelchair dynamometers remain the most reliable laboratory apparatus for assessing propulsion efficiency. This is because they measure the forces and torques the wheelchair generates during propulsion, which are the key determinants of these performance met  
Figure 13: Schematic illustration of the method of replacing an arbitrary set of points (**a**) with an ellipse defining the area of points on the analyzed plane (**b**) (source: [57]). rics. Biomechanical analysis methods can also provide valuable insights into wheelchair propulsion performance, but they are generally considered less valid and reliable than dynamometer-based methods. Biomechanical measurements are often indirect and can be influenced by factors such as joint alignment and muscle activation patterns. Both groups of laboratory testing methods require the efficient processing of large datasets to extract meaningful insights. Integrating diverse methods for wheelchair drive measurement is considered the most effective approach for comprehensive evaluation and analysis. Based on the literature analyses presented, the following conclusions can be drawn:  
1. Manual wheelchairs have many advantages and cannot be entirely replaced by electric wheelchairs, so developing ways to power them efficiently is worth learning about [58]. There is a noticeable trend of adapting the manual propulsion system to the individual physical capabilities of the user. This is achieved through hybrid drives or add-on modules like the anti-rollback system. 2. Multiple factors, including human characteristics, wheelchair design, and environmental conditions, influence the efficiency, safety, and comfort of manual wheelchair propulsion for individuals with mobility limitations [59]. Optimizing these factors can enhance the overall experience of using a manual wheelchair. 3. A wheelchair dynamometer has two functions: to simulate the actual operation conditions during laboratory testing and to measure several biomechanical parameters [31]. The simulation is achieved by changing the tilt angle of the wheelchair and controlling the dynamic force applied to the driving wheel of the wheelchair. The biomechanical parameters measured by the dynamometer include the COM position, measurement of wheelchair and human body kinematics, measurement of muscle effort using surface electromyography, and analysis of exhaled gases. Such a comprehensive evaluation of wheelchairs allows for gaining new knowledge for wheelchair design, user adjustment and fitting, and propulsion technique training. The dynamometer eliminates the physical linear motion of the wheelchair. Lack of sensation of wheelchair motion may interfere with the tests performed and lead to erroneous results [60]. It is, therefore, necessary to provide the user with information about the trajectory of the wheelchair during laboratory testing [47]. The location of the COM within the human-wheelchair biomechanical system is pivotal in determining propulsion efficiency and overall stability. For this reason, it is essential to study changes in the position of the COM under dynamic conditions [55]. Conducting biomechanical tests means collecting data at high frequency. This results in a large amount of data on which to base an analysis of the impact of the technical measure on humans. Working with large datasets is challenging and requires a lot of computational resources.