The purpose of this single-subject, concurrent mixed methods study is to investigate the relationship between the effect of the CIMT protocol on gait and mobility and participants' and caregivers' expectations and perceptions regarding the treatment. The goal of the quantitative strand is to assess changes in quality of movement and functional use of the paretic lower limb after the treatment and investigate the participants' expectations in regards the intervention using the Participant Opinion Survey (POS). The qualitative strand (participant interviews) will determine perspectives of caregiver and participant perspectives regarding protocol acceptability. Both quantitative and qualitative data will be collected and analyzed concurrently, through triangulation and complementarity rationales; both data will be equally prioritized.

About 66% of stroke survivors present gait impairment and mobility limitation. Rehabilitation techniques for people with walking and mobility disability after stroke have been broadly investigated in recent decades. However, few rehabilitation approaches have been shown to be effective in resolving these devastating problem.

Constraint-induced Movement Therapy (CIMT) presented robust evidence on increasing the amount and the quality of the paretic upper extremity (UE) functional use in daily situations of individuals with brain injuries (e.g. stroke, traumatic brain injury). The UE CIMT protocol consists of 4 components: 1) repetitive and intensive training; 2) motor training following shaping principles; 3) application of a groups of behavioral strategies called transfer package (TP), and 4) prolonged use of a restriction device on the non-paretic (or less affected) UE.

Considering the importance of repetition, intensity and specificity of the motor training to induce neuroplastic changes (3), CIMT is a potential tool to improve gait and mobility function in people with stroke. The translation of the UE protocol for Lower Extremity (LE) rehabilitation demanded some modifications for use with gait and mobility. For example, restraint of the less affected LE is not used because a different gait pattern would be induced using the restriction device. Also, the TP has been modified for LE function because of its inherent differences from UE function (e.g. both LE are more often used together and because there are more safety consequences involved with gait and mobility (e.g. falling).

In view of the significant efficacy of the UE CIMT for individuals with stroke, the extension of this approach to LE CIMT is promising, but investigation of its effect on mobility and motor function has been insufficient. The few studies that have applied a modified CIMT protocol in people with stroke did not use the full TP component. Thus, information about the effects of the complete CIMT protocol (i.e., including the TP) is greatly need. The addition of the enhanced TP in the LE protocol might have a great impact on both motor outcomes and retention of the results, as observed in previous studies about the UE approach. Considering the high intensity of the complete protocol, the added safety concerns, and the demand of involvement of the therapist, participant, and caregivers, the acceptability of the TP should be explored in order to provide a better understanding of the feasibility of this strategy.

The purpose of this single-subject, concurrent mixed methods study is to investigate the relationship between the effect of the CIMT protocol on gait and mobility and participants' and caregivers' expectations and perceptions regarding the treatment (e.g. intensity, physical and emotional demands, changes in routine). The goal of the quantitative strand is to assess changes in quality of movement and functional use of the paretic lower limb after the treatment and to investigate the participants' expectations in regards the intervention using the Participant Opinion Survey (POS). The qualitative strand (participant interviews) will determine perspectives of caregiver and participant perspectives regarding protocol acceptability. Both quantitative and qualitative data will be collected and analyzed concurrently, through triangulation and complementarity rationales; both data will be equally prioritized (4). We hypothesize that: 1) the enhanced LE CIT protocol will be effective for improving functional use of the paretic LE in people with chronic stroke; and 2) participant's and caregivers opinions are related to changes on functional use.

Aim 1: Assess the effects of the enhanced LE CIMT protocol on LE use and motor function. A single-subject ABA design with chronic stroke participants will be conducted. Individuals with different levels of severity will receive the LE CIMT, including intensive motor training and TP.

Aim 2: Richly characterize participants and caregivers acceptability of the LE CIMT protocol. A qualitative approach will be used for evaluating the acceptability of the protocol. The authors will conduct individual interviews with all participants and their caregivers or family members to determine perspectives of intervention.

Aim 3: Examine how participants and caregivers acceptability can influence changes in motor outcomes after LE CIMT. A mixed method approach will be conducted in order to investigate if there is relationship between effect on motor outcome and individuals' perceptions about the intervention.

Inclusion Criteria:

• be 19 years old or older,
• have more than 6 months after stroke;
• present motor impairment on lower extremity due to stroke, but able to walk at least 25 feet using an assistive device or not, at least three times a day;
• have no previous experience with any LE CIMT protocol.

Exclusion Criteria:

• presence of uncontrolled clinical conditions;
• presence of other neurologic diseases;
• Mini-mental State Examination score <24
• inability to answer yes and no questions properly;
• score lower than 45 out of 56 on the Berg Balance Scale, and score higher than 5 on LEMAL, what indicates that they are already utilizing the paretic lower limb while performing daily activities.