Lower Limb Flexor Synergy Training in Chronic Stroke

Methodist Rehabilitation Center

Status: Enrolling

Conditions: Stroke

Treatments: Other: Exercise training

Study type: Interventional

Funder types: Other

Identifiers

NCT03833544

MRC_StrFlxTraining

Details and patient eligibility

About

This study evaluates whether a 4-week exercise training program focusing on lower limb flexors can improve lower limb motor function late after stroke. It is hypothesized that there would be significant improvements in gait and strength of the flexor muscles as a result of the training. It is also hypothesized that the training effects, if any, would be retained at 4 weeks after ending the training.

Full description

It is known that the muscles that flex the hip, knee, and ankle joints are responsible for bringing the leg up and forward during walking and for a successful recovery from a slip or trip. Many previous studies have focused on strengthening the lower limb muscles that support the body in standing and walking (the so-called anti-gravity extensor muscles) but the training targeting the lower limb flexors has rarely been emphasized in stroke rehabilitation. Therefore, it is the intent of this exploratory study to find out whether an exercise training program focusing on lower limb flexors can improve lower limb motor function late after stroke.

Ten participants with chronic stroke will be recruited. Their lower limb muscle function and walking performance will be assessed at baseline (2 to 3 times within the 2 weeks prior to starting the training), at the end of training, and 4 weeks later.

Each subject will perform biking exercises under supervision, 2-3 times per week for 4 weeks (30 minutes each). The bike pedals are moving backward at a preset speed regardless of user effort. With feet strapped to the pedals, the participant will be asked to activate the hip, knee, and ankle flexors simultaneously when the pedal is moving up and then relax. Heart rate (HR) will be monitored continuously using a fingertip pulse monitor to ensure the maximum training HR is no more than 75% of the subject's HR Reserve.

Enrollment: 10 estimated patients

Sex: All

Ages: 21+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Time post-stroke between 6 months and 3 years
• Able to walk with or without an assistive device for 7 m independently
• Abnormal flexor synergy in both hip and knee joints (score 1 or 2) on the Fugl-Meyer Assessment Lower Extremity section II: Volitional movement within synergies (Fugl-Meyer et al., 1975)
• Walk slower than 1 m/s
• Able to understand and follow simple instructions
• Agree not to participate in strength training or supervised physical therapy during and for at least 4 weeks after the completion of training
• Previous participation in the physical therapy program for stroke without experiencing excessive symptoms (shortness of breath, headache, prolonged fatigue)

Exclusion criteria

• Current symptomatic coronary artery disease or congestive heart failure
• History of myocardial infarction
• Uncontrolled hypertension (>150/90 mm Hg)
• Lower limb fracture in the past 6 months
• Lower limb joint or muscular problems
• Acute or terminal illness
• Current participation in strength training or supervised physical therapy

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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10 participants in 1 patient group

Treatment Arm

Experimental group

Description:

Exercise training: Progressive resistance training of hip, knee, and ankle flexors.

Treatment:

Other: Exercise training