Towards Upright Pedalling to drive recovery in people who cannot walk in the first weeks after stroke: movement patterns and measurement

To examine whether people who are within 31days of stroke onset are able to produce controlled lower limb movement, and phasic activity in antagonistic lower limb muscle groups, during Upright Pedalling (UP).

Observational study.

Acute stroke unit within a University Hospital.

Eight adults between 3 and 30days from stroke onset, with unilateral lower limb paresis and unable to walk without assistance. Participants were considered fit to participate as assessed by a physician-led medical team and were able to take part in UP for one, one minute session.

Participants took part in one session of instrumented UP at their comfortable cadence, as part of a feasibility study investigating UP early after stroke.

Reciprocal activation of lower limb muscles derived from muscle activity recorded with surface EMG, quantified using Jaccards Coefficient (J); smoothness of pedalling determined from standard deviations of time spent in each of eight 45° wheel position bins ("S-Ped"). Motor behavioural measures: Motricity Index, Trunk Control Test, Functional Ambulatory Categories.

Participants were all unable to walk (FAC 0) with severe to moderate lower limb paresis (Motricity Index score/100 median 48.5, IQR 32 to 65.5). Smooth pedalling was observed; some participants pedalling similarly smoothly to healthy older adults, with a variety of muscle activation patterns in the affected and unaffected legs.

These observational data indicate that people with substantial paresis early after stroke and who cannot walk, can produce smooth movement during UP using a variety of muscle activation strategies.