FOA on Sit to Stand in Individuals Post Chronic Stroke

Overview

The purpose of this study is to fill some gaps in the literature by examining the effects of focus of attention on motor learning and motor performance of sit to stand in individuals post chronic stroke. This study will investigate whether an internal or external focus of attention can lead to improved use of the affected lower extremity during the sit to stand transition, while maintaining an upright trunk position. More specifically, the study has two purposes. The first is to determine whether an external or internal focus of attention would lead to better motor learning of sit to stand. This is measured by retention testing and transfer of the task to changes in affected lower extremity weight bearing during gait. The second purpose of this study is to investigate whether an internal or external focus of attention affects the performance of sit to stands during training.

Participant demographics and clinical information will be collected, including age, gender, weight, height, location of stroke, how long ago the stroke occurred, and fall history. All participants will consent to participation in this study. The Star Cancellation Test, NIH Stroke Scale (NIHSS), and Montreal Cognitive Assessment (MOCA) will be used to determine eligibility. Fugl Meyer Motor Scale for the lower extremity, excluding reflexes, will also be completed to help describe the sample. Blood pressure, heart rate, and oxygen saturation, via a pulse oximeter, will be taken and a gait belt will be placed on the participant prior to the start of baseline measures. Temporospatial gait parameters will be collected using the GAITRite mat at baseline, 5 minutes after training, and 1 hour after training. Temporospatial gait parameters will be averaged across four passes over the GAITRite mat at each measurement session. Participants will be instructed to 'walk past the end of the mat at your normal comfortable pace'. Participants will then be seated on a hi-lo table with their feet on the HR pressure mat for baseline assessment of sit to stand. Initial mat height will be determined by raising or lowering the mat table until the femur is parallel to the floor. In order to determine this, a level will be lined up from the greater trochanter to the lateral femoral condyle, while the fibula, from fibular head to lateral malleolus, is perpendicular to the floor. This initial mat position will be the height used during each reassessment at baseline, 5 minutes after training, and 1 hour post training. This height will also be used to decide the mat positions needed during training. After the initial mat height is achieved and recorded, an IMU marker will be placed on the superior third of the sternum directly inferior to the sternal notch. After the mat table height is set, participants will be asked to stand up and sit down to determine comfortable foot placement in relation to their knees. The toe of the affected lower extremity will be lined up with the toe of the unaffected side once they have achieved a comfortable foot placement. Tape marks will be placed in front of the toes and on the lateral edges of both feet as well as around the buttocks to allow for a standardized starting position for all assessment timepoints. For all data collection during baseline, 5 minutes post, and 1 hour post training, participants will be instructed to "please stand up three times at your normal speed without your arms if possible". The average force under the affected foot and the average overall force beneath both feet during the sit to stand transition will be captured by the HR pressure mat. The maximal lateral trunk position will be captured throughout this transition by the IMU marker. If individuals need to use their upper extremities this should be recorded. After baseline data collection, participants will be randomized into either the internal or external focus condition. Initial condition allocation will be determined by a random number generator (https://www.random.org), blocks of 6 with a 1:1 ratio. Condition assignment will be sealed in envelopes numbered for each participant by an independent researcher, who will otherwise not be involved in this research study. Condition allocation envelops will be opened directly prior to acquisition trials so baseline assessors will be blinded to group assignment of participants. Participants will be blinded to initial group assignment throughout the entirety of the sessions. Training Prior to training, a demonstration of the task will be provided to the participants. Those in the external focus condition will be told, "as you stand up and as you sit down try to bring the targets together like this". Those in the internal focus condition will be told, "as you stand up and as you sit down bring your right/left (R/L) shoulder and R/L hip as far to the R/L as possible." Participants will be asked to perform one repetition with the question "can you show me?". The demonstration is only provided before the first set but these same instructions will be given prior to the start of each successive set during training. During training trials, individuals will perform four sets of ten sit to stand repetitions. During the external focus condition, foam circles will be taped to the participant's lateral shoulder and lateral hip. In order to define this distance, participant girth will be measured in a seated position, by measuring the distance between bilateral outer thighs, using greater trochanters as landmarks. When the individual is standing in midline targets will be placed half of this girth measurement plus 10 centimeters away from the lateral tip of their acromion and another target placed the same distance away from their greater trochanter. During training, participants will perform four sets of sit to stand transitions with the mat at progressively lower seat heights to increasingly challenge the participants, with instruction and feedback consistent with their condition allocation. The four sets will occur in the following sequences: 130 percent of the initial mat height determined at baseline assessment, 120 percent, 110 percent and 100 percent. Each set will end after the tenth repetition or when the participant reports a RPE rating of \>15/20. If participants are unable to complete 10 repetitions, the number completed will be recorded for each trial. Two minute rest breaks will occur between each set or until the participant reports a rate of perceived exertion (RPE) of \<12/20 on the Borg RPE scale. During training, one verbal correction will be given during each set after the 2nd, 4th, and 7th trials, based on patient performance and condition allocation. The feedback provided will be recorded. Immediately after the training, participants will take a 5 minute break followed by the post-5 minute retention test in which instrumented sit to stand and gait will be administered. Following the retention test, individuals will complete a general health questionnaire. Approximately one hour after the training ends, 1-hour retention testing will be administered consisting of 3 instrumented sit to stands and gait over the GAITRite. After the immediate long term data collection, the participants will complete the post manipulation questionnaire to determine what the participants were focusing on during training. An investigator will guard the participant throughout the entirety of the protocol. One week later participants will return and complete the same protocol in the opposite attentional condition to which they were initially randomized. Each session should last 120 to 180 minutes.