The effect of crank position and backrest inclination on shoulder load and mechanical efficiency during handcycling

Abstract

Handbikes come in different models and setups, but only limited knowledge is available on the handbike-user interface. The aim of this study was to identify optimal handbike setups, assuming that in such a setup mechanical efficiency is high, while shoulder load is low. Thirteen subjects with a spinal cord injury (paraplegia) performed handcycling with different handbike setups at constant power output: four crank positions (two distances, two heights) and four backrest inclinations. The O2-consumption, kinetics, and kinematics were measured to calculate mechanical efficiency and shoulder load (glenohumeral contact force, net shoulder moments, and rotator cuff force). The analysis showed that more upright backrest positions resulted in lower shoulder load compared with the most reclined position [glenohumeral contact force (260 vs 335 N), supraspinatus (14.4% vs 18.2%), and infraspinatus force (5.4% vs 9.8%)], while there was no difference in efficiency. Except for a reduction in subscapularis force at the distant position, no differences in shoulder load or efficiency were found between crank positions. Recreational handbike users, who want to improve their physical capacity in a shoulder-friendly way, should set up their handbike with a more upright backrest position and a distant crank placement.

Elite handcycling: a qualitative analysis of recumbent handbike configuration for optimal sports performance

“…Quantitative studies manipulating handgrip width have been more conclusive, a handgrip width of 85 % of shoulder width was found to be optimal in a 4-second sprint (Krämer, Hilker, and Böhm 2009). Backrest inclination, affecting shoulder height and aerodynamics, has also been investigated by Arnet and her colleagues (2012;2014). A more reclined position (recumbent position 15°) increased shoulder load (Arnet et al 2014) but reduces air resistance which would lower power output, reducing shoulder load (Arnet et al 2012), for a given speed on the road.…”

Effect of Three Different Grip Angles on Physiological Parameters During Laboratory Handcycling Test in Able-Bodied Participants

“…Training with the optimal hand-crank orientation is essential for efficiency of movement, performance and the prevention of overuse risks (Webborn and Van de Vliet, 2012 ; Arnet et al, 2014 ). As the economy of movement when handcycling with the diagonal grip was only slightly, and non-significantly, higher than the other grip orientations for the able-bodied population, it would also seem important to consider comfort when setting up the handcycle, particularly for individuals with a loss of lower limb function.…”

“…In comparison to wheelchair propulsion, handcycling has a higher mechanical efficiency (Abel et al, 2003a ; Dallmeijer et al, 2004 ; Simmelink et al, 2015 ; Arnet et al, 2016 ), which gives the person restricted to a wheelchair the benefit of increased mobility. It has been postulated that regular engagement with handcycling will likely lead to fewer painful and debilitating overuse injuries (van der Woude et al, 2006 ; Arnet et al, 2014 ). Energy expenditure in handcycling is sufficient to offer protection against the development of secondary conditions such as cardiovascular disease (Abel et al, 2003a ; van der Woude et al, 2013 ).…”

“…Energy expenditure in handcycling is sufficient to offer protection against the development of secondary conditions such as cardiovascular disease (Abel et al, 2003a ; van der Woude et al, 2013 ). As a relatively new device there have been a range of areas investigated to improve handcycle performance, such as the influence of back rest position, gear ratios (Faupin et al, 2008 ; Arnet et al, 2014 ). Whilst the efficiency of the athlete and handcycle as a complete system has been assessed, the influence of some key components within this system have not yet been quantified, such as the type or orientation of the hand grip.…”

Shoulder and thorax kinematics contribute to increased power output of competitive handcyclists

“…It has been established in able‐bodied cycling that components of the bike and bike‐rider interface impact technique and potentially sports performance . Of the handcycling biomechanical literature, studies have established that factors such as exercise intensity and handbike configuration affect handcycling technique. However, these studies predominantly used able‐bodied or inexperienced handcyclists, exercising at ambulatory intensities using recreational (upright) handbikes, which limits the transferability to the sport of recumbent handcycling .…”