ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12625000139471p

Ethics application status

Submitted, not yet approved

Date submitted

18/01/2025

Date registered

7/02/2025

Date last updated

7/02/2025

Date data sharing statement initially provided

7/02/2025

Type of registration

Prospectively registered

Titles & IDs

Public title

Does task-specific strength training improve mobility after stroke?

Scientific title

Effect of task-specific (power) strength training on mobility in patients undergoing inpatient rehabilitation within 3 months following stroke

Secondary ID [1]

None

Universal Trial Number (UTN)

Trial acronym

Linked study record

The pilot trial examined the safety and feasibility of task-specific (power) strength training on mobility in patients following stroke, and provided the data for sample size calculations for the RCT.
Feasibility of Ballistic Strength Training in Subacute Stroke: A Randomized, Controlled, Assessor-Blinded Pilot Study. G. Hendrey et al. Archives of Physical Medicine and Rehabilitation 2018 Vol. 99 Issue 12 Pages 2430-2446. doi.org/10.1016/j.apmr.2018.04.032

Health condition

Health condition(s) or problem(s) studied:

Stroke

Condition category

Condition code

Physical Medicine / Rehabilitation

Physiotherapy

Stroke

Ischaemic

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

This is a prospective, multi-centre, randomised, single-blind trial of a 6-week program, conducted for 1 hour, 3 times per week (a total of 18 sessions) during the sub-acute phase of rehabilitation (< 3 months) which is the optimal period for recovery from stroke, with 20 week follow-up. Participants will be recruited from Epworth Healthcare, and the intervention will be either hospital or home-based for out-patients, depending on patient preference.
Intervention group
Participants will perform task-specific (power) resistance training tailored to the severity of their muscle paresis and performed according to the American College of Sports Medicine guidelines to ensure an optimal training stimulus and transfer of training gains. During normal walking, the joints have to move quickly, which means the leg muscles have to generate force quickly. Muscle power is the rate at which force is generated. Power training prioritizes the rate of force production compared to traditional strength training which has focused on slow-speed, high resistance exercises to maximize force production. Power training is task-specific for the muscles that provide power generation for forward propulsion when walking.

Task-specific (power) resistance training will focus on three main areas. First, the three key muscle groups responsible for forward propulsion (the ankle plantar-flexors, hip extensors and hip flexors) and faster walking speeds will be targeted. Second, a protocol for exercise progression has been included, ensuring the participants perform power training correctly, quantified by the rate of force development measured using a string potentiometer whilst supervised by a trained research assistant. Supervision is vital for safe and accurate power training implementation. Initial loads will be low to facilitate high contraction velocities for power training. Third, specific power training exercises will be performed in the range through which the muscle is active when walking. When participants can consistently perform power training at the required speed (for example, approaching 300°/s at the ankle joint), the load will be progressively increased. Examples of power training exercises used in the pilot RCT and large traumatic brain injury trial include;
1) calf hops on a ‘leg sled’ (targeting ankle plantar-flexors)
2) reciprocal leg extension on a mini-trampet (mini-trampoline, targeting ankle plantar-flexors)
3) step and stair descent (targeting the loading response phase and terminal stance)
4) fast cyclical hip and knee flexion in standing (targeting hip flexors)
5) As per 4 with additional resistance (targeting hip extensors)
6) Fast walking to translate training gains from power training into walking.

Standard principles governing frequency, duration, intensity, repetitions, rest periods and progression of resistance exercises will be applied in order to ensure an optimal training stimulus. Power training has very few adverse events reported for people with neurological conditions, and no adverse events were associated with the intervention in our pilot trial.

Both Groups
The majority of participants will commence the trial during the inpatient phase of rehabilitation where they receive multi-disciplinary therapy (including physiotherapy, occupational and speech therapy). Physiotherapy is typically provided twice daily on weekdays (i.e. 10 sessions/week). Physiotherapy for stroke usually comprises balance training, stretching, cardiovascular fitness training and traditional resistance training.34, 35 It also includes walking tasks that are important for community mobility (e.g. walking indoors and outdoors, negotiating slopes, uneven surfaces and gutters). Participants in both groups will continue to receive typical physiotherapy provided after stroke for seven sessions/week. Participants randomised to the Experimental Group will replace three sessions of physiotherapy with task-specific (power) resistance training and fast walking each week, and participants randomised to the Control Group will replace three sessions of physiotherapy with traditional resistance training and community walking.

In order to ensure the exercises in each group are conducted according to the training protocols, a trained physiotherapist or exercise physiologist will supervise every session for each participant. Sessions will be administered individually (i.e. 1:1). Attendance will be recorded, and time spent performing each exercise in each group will be documented. In order for participants to have satisfactorily completed the trial = 80% of sessions (15 sessions) must be completed.

The pilot RCT was registered on clinicaltrials.gov: NCT01958736.

Intervention code [1]

Rehabilitation

Comparator / control treatment

Control group/usual care participants will attend 1 hour sessions, 3 times per week for 6-weeks (a total of 18 sessions). In order to ensure the exercises in each group are conducted according to the training protocols, a trained physiotherapist or exercise physiologist will supervise every session for each participant. Sessions will be administered individually (i.e. 1:1). Participants will be recruited from Epworth Healthcare, and the intervention will be either hospital or home-based for out-patients, depending on patient preference.

Usual care
Participants will perform traditional slow-speed high resistance leg exercises, also tailored to the severity of their muscle paresis and performed according to the American College of Sports Medicine guidelines for muscle strength training in addition to usual care rehabilitation. Traditional slow-speed resistance training typically comprises leg curls, calf raises, squats, calf raises and hip abduction. Participants in the Control Group will also practice walking (outside, over varying slopes and surfaces, gutters).

Both Groups
The majority of participants will commence the trial during the inpatient phase of rehabilitation where they receive multi-disciplinary therapy (including physiotherapy, occupational and speech therapy). Physiotherapy is typically provided twice daily on weekdays (i.e. 10 sessions/week). Physiotherapy for stroke usually comprises balance training, stretching, cardiovascular fitness training and traditional resistance training. It also includes walking tasks that are important for community mobility (e.g. walking indoors and outdoors, negotiating slopes, uneven surfaces and gutters). Participants in both groups will continue to receive typical physiotherapy provided after stroke for seven sessions/week. Participants randomised to the Experimental Group will replace three sessions of physiotherapy with task-specific (power) resistance training and fast walking each week, and participants randomised to the Control Group will replace three sessions of physiotherapy with traditional resistance training and community walking.

Control group

Active

Outcomes

Primary outcome [1]

Mobility

Timepoint [1]

Week 0, 6 (primary endpoint) and 26 (post-commencement of intervention).

Secondary outcome [1]

Muscle power generation - hip flexors

Timepoint [1]