Crank length alters kinematics and kinetics, yet not the economy of recumbent handcyclists at constant handgrip speeds

Handbike configurations and the prevalence of experienced sitting and riding-related problems in recreational handcyclists training for the HandbikeBattle

The purpose of this study was to describe handbike configurations and the prevalence of experienced sitting and riding-related problems among recreational handcyclists training for a mountain time trial (HandbikeBattle). In this cross-sectional study, 150 participants of the HandbikeBattle, who used an arm-power (recumbent) handbike, filled out a questionnaire (on comfort, stability and power generation) while handbike characteristics were measured. Crank width was variable among handcyclists and was wider than the shoulder width (median crank/shoulder width ratio: 1.19). About 60% of the participants found sitting in the handbike never fatiguing or painful and 74-76% indicated to sit stable in the handbike when sitting or when generating power. About 80% of the participants thought that their pedal position was optimal. Although the overall scores regarding sitting position and riding settings were high (both questions median: 8.0 on 1.0-10.0 scale), 50% and 31% of the participants, respectively, believed that their sitting position and riding settings could be improved. In addition, 10% of the participants thought that the configuration could lead to an injury and had an injury at the time of filling out the questionnaire. It can be concluded that although the majority of the participants seemed to be satisfied with their handbike configurations a large variety in handbike configurations was seen. There is a need for the development of evidence-based guidelines for handbike fitting in the future.

Adaptive Sports and Recreation in Persons with Limb Loss/Limb Deficiency

Adaptive sports are a vital component in the continuum of rehabilitation for people with limb loss/limb deficiency (LL/LD), across the lifespan. Identifying the barriers and understanding health care disparities inform ways to help people with LL/LD stay active and reach their health and wellness goals. Building knowledge in adaptive sports helps facilitate having a person go beyond activities of daily living and basic locomotion. Considering the participant, requirements of the sport, and the activity-specific prosthesis/equipment required leads to successful participation in adaptive sports.

Moving forward: A review of continuous kinetics and kinematics during handcycling propulsion

Wheelchair users (WCUs) face high rates of shoulder overuse injuries. As exercise is recommended to reduce cardiovascular disease prevalent among WCUs, it is becoming increasingly important to understand the mechanisms behind shoulder soft-tissue injury in WCUs. Understanding the kinetics and kinematics during upper-limb propulsion is the first step toward evaluating soft-tissue injury risk in WCUs. This paper examines continuous kinetic and kinematic data available in the literature. Attach-unit and recumbent handcycling are examined and compared. Athletic modes of propulsion such as recumbent handcycling are important considering the higher contact forces, speed, and power outputs experienced during these activities that could put users at increased risk of injury. Understanding the underlying kinetics and kinematics during various propulsion modes can lend insight into shoulder loading, and therefore injury risk, during these activities and inform future exercise guidelines for WCUs.

Propulsion kinetics of recumbent handcycling during high and moderate intensity exercise

People with spinal cord injuries (PwSCI) are at high risk of developing cardiovascular disease (CVD). While regular exercise can reduce risk of CVD, PwSCI face various barriers to exercise, including high rates of upper limb injuries, especially in the shoulder. Handcycling high intensity interval training (HIIT), which consists of periods of high intensity exercise followed by rest, is a potential exercise solution, but the musculoskeletal safety of HIIT is still unknown. In this study, we characterized three-dimensional continuous applied forces at the handle during handcycling HIIT and moderate intensity continuous training (MICT). These applied forces can give an early indication of joint loading, and therefore injury risk, at the shoulder. In all three directions (tangential, radial, and lateral), the maximum applied forces during HIIT were larger than those in MICT at all timepoints, which may indicate higher contact forces and loads on the shoulder during HIIT compared to MICT. The tangential and radial forces peaked twice in a propulsion cycle, while the lateral forces peaked once. Throughout the exercises, the location of tangential peak 2 and radial peak 1 was later in HIIT compared to MICT. This difference in maximum force location could indicate either altered kinematics or muscular fatigue at the end of the exercise protocol. These changes in kinematics should be more closely examined using motion capture or other modeling techniques. If we combine this kinetic data with kinematic data during propulsion, we can create musculoskeletal models that more accurately predict contact forces and injury risk during handcycling HIIT in PwSCI.

Association between upper-limb isometric strength and handcycling performance in elite athletes

This study investigated the association among isometric upper-limb strength of handcyclists and sport-specific performance outcomes. At two international events, 62 athletes were tested on upper-limb strength, measured with an isometric-strength setup and with Manual Muscle Test (MMT). Horizontal force (Fz), effectiveness, rate of development, variability, and asymmetries were calculated for upper-limb pull and push. Performance measures were mean (POmean) and peak (POpeak) 20-s sprint power output and average time-trial velocity (TTvelocity). Regression models were conducted to investigate which pull and push strength variables associated strongest with performance measures. Additional regression analyses were conducted with an MMT sum score as predictor. Push and pull Fz showed the strongest associations with all outcomes. Combined push and pull Fz explained (p < .001) 80-81% of variance of POmean and POpeak. For TTvelocity, only push Fz was included in the model explaining 29% of the variance (p < .001). MMT models revealed weaker associations with sprint PO (R2 = .38-.40, p < .001) and TTvelocity (R2 = .18, p = 0.001). The findings confirmed the relevance of upper-limb strength on handcycling performance and the significance of ratio-scaled strength measures. Isometric strength outcomes are adequate sport-specific indicators of impairment in handcycling classification, but future research should corroborate this notion and its potential to discriminate between sports classes.

The Science of Handcycling: A Narrative Review

The aim of this narrative review is to provide insight as to the history, biomechanics, and physiological characteristics of competitive handcycling. Furthermore, based upon the limited evidence available, this paper aims to provide practical training suggestions by which to develop competitive handcycling performance. Handbike configuration, individual physiological characteristics, and training history all play a significant role in determining competitive handcycling performance. Optimal handcycling technique is highly dependent upon handbike configuration. As such, seat positioning, crank height, crank fore-aft position, crank length, and handgrip position must all be individually configured. In regard to physiological determinants, power output at a fixed blood lactate concentration of 4 mmol·L−1, relative oxygen consumption, peak aerobic power output, relative upper body strength, and maximal anaerobic power output have all been demonstrated to impact upon handcycling performance capabilities. Therefore, it is suggested that that an emphasis be placed upon the development and frequent monitoring of these parameters. Finally, linked to handcycling training, it is suggested that handcyclists should consider adopting a concurrent strength and endurance training approach, based upon a block periodization model that employs a mixture of endurance, threshold, interval, and strength training sessions. Despite our findings, it is clear that several gaps in our scientific knowledge of handcycling remain and that further research is necessary in order to improve our understanding of factors that determine optimal performance of competitive handcyclists. Finally, further longitudinal research is required across all classifications to study the effects of different training programs upon handcycling performance.