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

Current knowledge on recumbent handbike configuration and handcycling technique is limited. The purpose of this study was to evaluate and compare the upper limb kinematics and handbike configurations of recreational and competitive recumbent handcyclists, during sport specific intensities. Thirteen handcyclists were divided into two significantly different groups based on peak aerobic power output (POpeak) and race experience; competitive (n=7; 5 H3 and 2 H4 classes; POpeak: 247±20W) and recreational (n=6; 4 H3 and 2 H4 classes; POpeak: 198±21 W). Participants performed bouts of exercise at training (50% POpeak), competition (70% POpeak), and sprint intensity while three‐dimensional kinematic data (thorax, scapula, shoulder, elbow and wrist) were collected. Statistical parametric mapping was used to compare the kinematics of competitive and recreational handcyclists. Handbike configurations were determined from additional markers on the handbike. Competitive handcyclists flexed their thorax (~5°, P<0.05), extended their shoulder (~10°, P<0.01) and posteriorly tilted their scapular (~15°, P<0.05) more than recreational handcyclists. Differences in scapular motion occurred only at training intensity while differences in shoulder extension and thorax flexion occurred both at training and competition intensities. No differences were observed during sprinting. No significant differences in handbike configuration were identified. This study is the first to compare the upper limb kinematics of competitive recreational handcyclists at sport‐specific intensities. Competitive handcyclists employed significantly different propulsion strategies at training and competition intensities. Since no differences in handbike configuration were identified, these kinematic differences could be due to technical training adaptations potentially optimising muscle recruitment or force generation of the arm

Horizontal crank position affects economy and upper limb kinematics of recumbent handcyclists

Purpose: To determine the effects of horizontal crank position on economy and upper limb kinematics in recumbent handcycling. Methods: Fifteen trained handcyclists performed trials at 50% and 70% of their peak aerobic power output (POPeak), determined during a maximal ramp test, in each horizontal crank position. Four horizontal crank positions, 94%, 97%, 100% and 103% of arm length, were investigated. Horizontal crank positions were defined as the distance between the acromion angle to the centre of the handgrip, while the crank arm was parallel to the floor and pointing away from the participant. Economy and upper limb kinematics were calculated during the final minute of each three-minute trial. Results: Horizontal crank position significantly affected handcycling economy at 70% POPeak (P < 0.01) but not at 50% POPeak (P = 0.44). The 97% horizontal crank position (16.0 (1.5) mL·min-1·W- 1 ) was significantly more economical than the 94% (16.7 (1.9) mL·min-1·W-1 ) (P = 0.04) and 103% (16.6 (1.7) mL·min-1·W-1 ) (P < 0.01) positions. The 100 % horizontal crank position (16.2 (1.7) mL·min-1·W-1) was significantly more economical than the 103% position (P < 0.01). Statistical parametric mapping indicated that an increase in horizontal crank position, from 94% to 103%, caused a significant increase in elbow extension, shoulder flexion, adduction, internal rotation, scapular internal rotation, wrist flexion, clavicle depression and clavicle protraction between 0 – 50 % (0° - 180°) of the cycle (P < 0.05). Conclusion: Positioning the cranks at 97% to 100% of the athletes’ arm length improved handcycling economy at 70% POPeak as, potentially, the musculature surrounding the joints of the upper limb were in a more favourable position to produce force economically

Validity and reliability of sensor system to measure trunk range of motion during Streamlined Wolf Motor Function Test in chronic stroke and aged-matched healthy participants

To investigate the validity and reliability of using the Valedo® system to measure trunk Range of Motion (ROM) during performance of the streamlined Wolf Motor Function Test (SWMFT). Twenty chronic strokes and 20 age-matched healthy participants performed SWMFT while wearing Valedo® sensors on their trunks to capture trunk movements. A paired sample T-test was used to examine the validity of the system in distinguishing between the healthy and stroke group, and between the affected and unaffected sides in the stroke group. Interclass correlation coefficients were used to assess the inter-rater and intra-rater reliability (between-days) with 95% CI. The Valedo® system was able to distinguish between stroke and healthy participants; stroke participants employed greater trunk range of movements than the healthy controls in all tasks (p  The Valedo system demonstrates an acceptable level of validity and reliability for measuring trunk ROM during the Streamlined Wolf Motor Function Test (SWMFT). Future studies with a larger sample size, different levels of upper limb impairment are warranted.</p