Machines Assisting Recovery From Stroke: Robotic Activity Mobility Center in a Fitness Center for People With Neurologic Disability
Phase: NA
Conditions: Cerebrovascular Disease; Sequelae
Sponsor: University of Alabama at Birmingham

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
Jennifer Uzochukwu, MS; David A. Brown, PT, PhD 
 
1 
 
 
 
 
 
Study Title: “Machines Assisting Recovery from Stroke: Robotic Activity 
Mobility Center in a Fitness Center for People with Neurologic Disability” 
NCT #: NCT02787694 
 
Date: March 1, 2017 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
2 
 
OBJECTIVE: We discuss our study protocol, which involved the use of five targeted training 
domains in the KineAssist®-MX robotic treadmill device aimed to challenge participants, who 
were at least four months post-stroke, in various walking conditions. The training domains were 
to provide similarities to real life walking challenges they may encounter during community-
ambulation.  
 
Study Center: All study meetings, participant assessments and training sessions were conducted 
at the UAB Locomotor Control and Rehabilitation Robotics Laboratory. 
 
 
METHODS/DESIGN: DEVICE 
 
KineAssist®-MX  
The KineAssist®-MX (KA-MX) is a self-driven treadmill that 
allows users to control the speed and direction (forward or 
backward) of the belt. Pelvic forces are detected by force 
transducers in the pelvic mechanism, and an embedded 
computer sets the velocity of the belt based on the amount and 
direction of the forces applied. It offers a body weight support 
mechanism, which allows individuals to freely practice a variety 
of exercises and skills that simulate real world activities while 
also catching the user in the event of an unintended fall or loss 
of balance.  
 
 
METHODS/DESIGN: PARTICIPANTS AND TRAINING 
 
Inclusion Criteria:  
1. Community dwelling unilateral stoke survivors 
2. 19 years of age or older 
3. 4 months or more post incident with residual hemiplegia 
4. Able to ambulate at least 14 m with an assistive device or the assistance of one person 
5. Have receptive and expressive communication capability 
6. Approval of treating physician and voluntarily provided informed consent 
7. Modified Mini-Mental State Exam score  24 
 
Exclusion Criteria: 
1. Significant and acute medical conditions or amputations 
2. Spasticity management that included phenol block injections within 12 months or 
botulinum toxin injections within 4 months of the study 
3. Any cognition involvement that impairs the ability to follow directions  
4. Plans to move out of the area within the next year or no transportation to the study area 
 
 
 
 
Figure 1. User in KineAssist-MX 
device wearing the attached pelvic 
harness 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
3 
 
Pre-Post Participant Evaluations 
Participants were evaluated by a licensed physical therapist (PT) at baseline, post-intervention 
and at six months post-study intervention to determine if the effects of the trainings were 
sustained. The PT was blinded to the biweekly trainings received by participants. The 
evaluations consisted of a Six-Minute Walk Test (Pohl et al., 2002) as a measurement of walking 
capacity, 10-Meter walk test (Bohannon, 1997) as an assessment of the participant’s slow and 
fast comfortable walking speeds, the lower extremity Fugl Meyer to quantify hemiparetic motor 
impairments (Mehrholz, et al., 2007), the Berg Balance Scale (Blum, 2008) as a measure of 
balance and fall risk, Geriatric Depression Scale (Yesavage, et al., 1982) as a measure of 
emotional state, Activities-Specific Balance Confidence Scale (Powell & Myers, 1995) as a 
measure of participants’ confidence in performing ambulatory tasks without loss of balance, 
Dynamic Gait Index (An, et al., 2016) as a measure of participants’ ability to modify balance 
demands during walking, Modified Mini-Mental State Exam (Folstein et al., 1975) as a measure 
of cognitive impairment (score  24), and the Stroke Impact Scale (Michaelsen, 2014) as a 
measure of health status post-stoke. Time points for when these evaluations were used 
throughout the study are seen in Table 1.  
 
 
Table 1. Participant Evaluations at Study Time Points 
Evaluation 
Baseline 
Post-Intervention 
6-Month Follow Up 
6-Minute Walk test 
X 
X 
X 
10-Meter Walk Test 
X 
X 
X 
Activities-Specific 
Balance Confidence 
Scale 
X 
X 
X 
Berg Balance Scale 
X 
X 
X 
Geriatric Depression 
Scale 
X 
X 
X 
Dynamic Gait Index 
X 
X 
X 
Lower Extremity 
FUGL-MEYER-Motor 
Function (Part 5) 
X 
 
 
Modified Mini Mental 
State Exam 
X 
 
 
Stroke Impact Scale 
X 
X 
X 
 
 
Training Paradigms 
Participants had targeted biweekly trainings based on assessments (differs from PT pre-post 
evaluations). There were five training domains: hyperspeed, aerobic, strength, locomotor 
challenge, and balance (Table 2). Each biweekly training focus was selected based on the scoring 
of all domains assessed during biweekly assessments. Training sessions were three times a week 
and designed to last 30 minutes excluding time for setup and dismount (heart rate monitor, 
transition in and out of KA-MX device) and calculations (heart rate and blood pressure); 
however, it could also be longer depending on the number of rest breaks taken by participants 
allowing for individuation based on ability and comfort. Each session consisted of multiple bouts 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
4 
 
(5 minutes each) depending on the training domain. Participants were encouraged to aggregate 
bouts with training progression (i.e., minimize rest breaks). Manual assistance by research 
assistance was not provided during training except in the case of aiding participants training in 
the stepping domain.  
 
Participant Body Weight Support Determination: The participant’s body weight support 
(BWS) was attained by use of a 10-meter walk test at 0%, 10%, 20%, and 30% BWS in the 
KineAssist-MX device. The lowest BWS that generated the highest comfortable walking speed 
(CWS)(0.08 m/s, FWS) was used for the training to allow for individualization of the training 
session. It was calculated for each training session.  
 
Heart Rate and Blood Pressure: Heart rate (HR) and blood pressure (BP) was monitored 
throughout the training and during respective challenges/activities. Prior to training, the target 
heart rate was determined according to the Karvonen formula (Karvonen & Vuorimaa, 1988) and 
adjusted based on whether participants were on beta blockers. Participants targeted 60-80% of 
their heart rate reserve during the 30-minute training sessions. If they exceeded 80% of their 
heart rate reserve, participants were given a seated or standing rest break to allow their HR to fall 
below 60% of their target before continuing with training. Pre and post session training, BP was 
monitored. If it was too low or too high, participants were allowed to rest for approximately 10 
minutes before their BP was rechecked. If it remained the same, they were dismissed to go home 
or to visit their primary care physician before returning for another visit. In some cases, 
participants were placed in the KA device and carefully monitored to see if their BP would 
remain the same (still low or still high) or improve. If it improved with exercise, then they were 
cleared to begin training; otherwise, they were allowed to go home.  
 
 
Table 2:  The Five Targeted Training Domains 
Training 
Purpose 
Bout Characteristics 
Performance 
measure(s) 
Hyperspeed 
To continually challenge 
participants to walk at their fastest 
successful speed without losing 
balance 
Each bout consists of 
alternation between 40 s at 
CWS and 20 s at FSS 
 
3 bouts of approximately 5 
minutes each 
# of successes (i.e. no 
loss of balance) for FSS 
Aerobic 
To challenge participants to reach 
60-80% of target HR reserve and 
build aerobic capacity 
Each bout consists of 
walking at 60-80% target 
HR reserve 
 
6 bouts of approximately 5 
minutes each 
HR/min 
RPE 
Distance per bout  
Total distance 
# of rests   
# of falls  
Strength 
To challenge participants to walk 
against increasing horizontal 
resistance 
Each bout consists of 
walking at a 12-step 
maximum force level for 
both legs 
 
6 bouts of approximately 5 
minutes each 
Distance per bout  
Total distance  
HR 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
5 
 
Locomotor Challenge 
To provide nine locomotor 
challenges that simulate what an 
individual typically encounters 
while walking in the real world.  
 
 
 
 
Long stepping (LS) 
 
 
 
 
 
 
 
Each bout consists of one 
challenge  
 
 
2 bouts per challenge of 
approximately 5 minutes 
each 
 
3 challenges per day 
HR/min  
RPE every 2 min 
Distance per bout 
# of rests 
# of falls 
 
  
LS - Max step length 
 
Speeding up and slowing down 
(SU/SD) 
SU/SD – FSS 
 
Head turns (HT) 
 
HT – success of head 
turns (i.e. no loss of 
balance) 
 
Hurdles (H) 
H – successful max 
height clearance (i.e. no 
collision with hurdle) 
 
Backward perturbation during 
forward walking (BP/FW) 
 
BP/FW – highest 
successful perturbation 
distance and velocity 
without loss of balance 
 
Backward walking (BW) 
 
HR/min  
RPE every 2 min 
Distance per bout 
# of rests 
# of falls 
Foam shoes (FS) 
FS – height of foam 
successfully used while 
walking 
Narrow stepping (NS) 
NS - narrowest 
successful step width 
distance 
Sideways walking (SW) 
HR/min  
RPE every 2 min 
Distance per bout 
# of rests 
# of falls 
 
Dynamic Balance 
To provide nine balance challenges 
to simulate what an individual 
might encounter in their day to day 
lives 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Each bout consists of one 
challenge  
# of attempts 
 
# of successes (i.e. no 
loss of balance) 
 
HR after each 5 min 
bout, when necessary 
 
BP after each 5 min 
bout, when necessary 
 
Step onto Step (SOS) 
SOS - Highest step 
height without losing 
balance 
 
Forward Step Length (FSL) 
FSL - Longest step 
without losing balance 
 
Slippery Surface (SS) 
SS - Largest tilt angle 
held without losing 
balance  

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
6 
 
 
Stepping onto Foam (SF) 
 
 
2 bouts (one per leg) per 
challenge of 5 minutes 
each 
 
3 challenges per day 
 
 
3 successful attempts 
(doesn’t have to be 
consecutive) before 
moving on to next level 
within each 5 min 
challenge bout 
 
SF - Highest foam 
height without losing 
balance 
 
Forward Perturbation (FP) 
FP - Greatest distance 
and velocity at which 
participant held their 
balance without taking 
a step due to 
perturbation 
 
Backwards Perturbation (BP/FW) 
BP/FW - Greatest 
distance and velocity at 
which participant held 
their balance without 
taking a step due to 
perturbation 
 
Forward Reach (FR) 
FR - Farthest target 
distance participant is 
able to reach with their 
hand without losing 
balance 
 
Sit to Stand (SST) 
SST - Lowest height 
participant is able to 
stand up from without 
losing balance and 
without using their 
hands for support 
 
Hurdle (H) 
H - Highest hurdle 
clearance without loss 
of balance or collision 
with hurdle 
*FSS = fastest successful speed, CWS – comfortable walking speed, HR = heart rate, RPE – 
rating of perceived exertion 
 
 
Training Domains: 
 
Hyperspeed Domain 
The goal of the training was to challenge the participants to walk at their fastest successful speed 
(FSS) without loss of balance. The participant trained at their ideal BWS according to the BWS 
level determination (see above). 
 
Determination of FSS: The participant targeted walking at a maximum of their CWS + 0.2m/s. 
The speed of the treadmill belt was gradually increased until reaching CWS + 0.2m/s. The 
participant was instructed to maintain that speed for 10 steps at a maximum of 20 seconds. 
Success or loss of balance was recorded, and the participant was asked whether they were willing 
to try a faster speed. If so, they were instructed to target the previously recorded FSS + 0.2m/s, 
and again to maintain the speed for 10 steps at a maximum of 20 seconds. This continued until 
five 20-second attempts at FSS were completed with incremental increases based on the 
previously successful FSS or the participant could no longer walk at the targeted speed or 
declined to go faster. Between FSS attempts, the participant gradually walked up to their CWS 
and maintained that speed for 40 seconds before targeting 10 steps at the FSS. This was repeated 
until the 5 rounds are completed whereby the participant walked for 40 seconds at their CWS. 
The bout lasted approximately five minutes.  

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
7 
 
 
The participant was allowed to rest for 2-3 minutes (seated or standing based on preference) and 
their heart rate was checked to ensure that it fell below their 60% target before continuation with 
the next five-minute bout. The training process was repeated until three total bouts were 
completed. The next training session used the FSS from the previous session as the initial target 
of the first bout. 
 
Aerobic Domain 
This domain allowed the participant to walk for six 5-minute bouts on the treadmill without 
stopping unless the participant requested to do so as a rest break or their target hear rate 
exceeded 80% of their heart rate reserve target. BWS support was selected based on the BWS 
level determination. Heart rate was recorded every minute and the participant was asked to rate 
how hard they perceived themselves to be working after every two minutes according to the 
Borg Scale (rating of 6 – 20; Noble et al., 1983; Borg et al., 1987). This was done to have both a 
physiological and subjective measure of exertion. We were interested to know if both measures 
were correlated.   
 
After completion of each 5-minute bout, the participant was given the option to continue for 
another five minutes or rest. The process was repeated until a full 30 minutes of training was 
completed. Distance was recorded using a Stanley wheel placed at the front of the treadmill belt 
to measure the distance of the moving belt during each 5-minute bout yielding total distance 
traveled by the participant.  
 
Strength Domain  
BWS was selected according to the BWS determination level. The participant was instructed to 
walk at their CWS for 30 seconds then for 12 steps (with both legs) with the addition of the 
appropriate amount of horizontal resistance.  
 
Resistance Determination: Resistance was applied by selecting a deadband level of force (i.e. 
amount of force required to initiate belt movement using the self-drive mechanism of the 
KineAssist-MX).  For the first bout of the session, the participant targeted 20% of their CWS 
and an initial deadband of 5N. Additional 5N was added if the initial +5N was insufficient to 
reduce speed by 20%. For every 12-step interval, 5N was added to increase the challenge level. 
The task was considered “too hard” only when there was a 20% drop in walking speed.  
Following the 12 steps, deadband was returned to a default of 2N and the participant was 
allowed to walk again for 30 seconds at CWS. If training was not the first bout of the first 
session, the bout began with the highest level of deadband from the past session. Deadband was 
then added or removed throughout the bout as tolerated by the participant.  
 
Each session consisted of six bouts of approximately five minutes totaling 30 minutes. It was 
therefore formatted as five intervals comprising of the 1st 30 seconds at CWS, 1st 12 steps at 
resistance, 2nd 30 seconds at CWS, 2nd 12 steps at resistance up until the 5th interval. Heart rate 
was recording between intervals (i.e., directly after completion of 12 steps at respective 
deadbands).   
 
 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
8 
 
Locomotor Challenge Domain 
Tasks were demonstrated prior to starting. BWS was selected according to BWS determination 
level. 
 
Long stepping: This test was designed to train the participants to take long steps in order to 
simulate common challenges posed in the real world of stepping over environmental hazards, 
such as puddles of water or potholes. The participant was instructed to walk at their CWS and 
take the longest step he/she can with the non-paretic leg. After examination of the participant’s 
heel strike position (point 0), an infrared laser was aligned with that position and the participant 
was instructed to step over the laser line while walking. Successful completion of a trial 
constituted 5 consecutive strides (5 steps each leg) taken with heel strike at or past the laser line. 
Three tries are given to pass each trial. Passing resulted in the increase of laser position by one 
inch. 
 
Speeding up and slowing down: This task was used to simulate and help improve the speed up 
and slow down one does throughout ambulation. Using the speed up/slow down setting in the 
KA-MX devise, “nominal speed” was set to the participant’s CWS, “hold time” was set to 10 
seconds, “plus/minus” was set to  0.2 m/s and “trials” was set to 30 and thus constituting five 
minutes for a bout. The participant was encouraged to walk whereby the green trace on the KA 
device screen matched the yellow goal line. The devise essentially sped up and slowed down, 
and the participant was instructed to keep up with it as best as they could.   
 
Head turns: This task was designed to simulate the need to turn and observe different directions 
during ambulation without losing balance. The participant began by walking at their CWS. At 10 
second intervals, they were instructed to turn their head either up, down, left or right and to 
maintain the position for 10 seconds. If this task was too easy, then we added shaking the head 
left and right, and up and down.  Successful maintenance of CWS with their head turned resulted 
in slow-fast combinations of the sequences such as “look up and down, close your eyes, open 
your eyes and look forward.” This cycle continued per each minute of training.   
 
Hurdles: This task simulated and trained for stepping over objects in the environment. The 
participant was instructed to step over a hurdle positioned at a 2-inch height in front of their non-
paretic leg while walking at their CWS. The height was lowered if the participant could not step 
over the given height. If there was consistent clearance of the hurdle, however, there was an 
increase in one inch of the hurdle height, until the person was just barely able to clear the hurdle. 
This was practiced for 5 minutes per foot (i.e., one bout per foot).  
 
Backward perturbation during forward walking: This task was designed to simulate the 
interruptions (other people or objects) encountered during walking and improve the individual’s 
reactionary balance control. The perturbation push program on the KA device was set to a 
default of 0.48 peak velocity and 0.40 distance. The participant was allowed to walk at their 
CWS and once reaching steady state, backward perturbation was introduced approximately every 
10 seconds. If the perturbation was tolerated well by the participant (i.e. no loss of balance), the 
distance and peak velocity was increased by intervals of 0.1 on the device. This continued until 
the perturbation posed a challenge to participants and was repeated for the second bout after a 2-
3-minute rest break.   

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
9 
 
 
Backward walking: This task simulated the act of walking backwards without the loss of 
balance. The participant was instructed to walk backwards in the KA device for 5 minutes (one 
bout) at a speed that attained their target HR. In any event that the participant fell with the KA 
safety catch was engaged, the task was reset on the device and the 5-minute period continued 
uninterrupted.  
 
Walking with foam shoes: This task simulated walking on uneven surfaces and surfaces of 
varying height, and also intended to improve the participant’s proprioceptive ability. Foam 
blocks were attached to the participant’s shoes while seated in the device. We had two heights, 
2” and 4” and initially began with the thin foam. The participant was instructed to put their 
weight into the shoes to avoid slack and walk at their CWS to attain target HR. If the foam size 
did not pose a struggle for the participant (i.e., successful maintenance of CWS), it was changed 
to thicker foam (4 inches) until reaching the 5-minute stopping point for the bout before 
continuing to the next bout. 
 
Narrow stepping: This task was designed to simulate narrow steps one has to take in an 
environment with a narrow walking path (e.g. hallway). The participants were instructed to take 
the narrowest step that they could. A laser beam was fitted to this narrowest step. The goal was 
to challenge the participant rather than induce a loss of balance. Once the step width distance 
was the determined, the participant was instructed to walk at their CWS within that width for 5 
minutes (one bout). The trial was repeated for the second bout.    
 
Sideways walking: This task was designed to simulate sideways walking in the environment 
when one is required to turn to maneuver a path. The participants were instructed to walk 
sideways towards their affected or weaker limb at their CWS for 5 minutes. The goal was to 
walk without a loss of balance and attain target HR with appropriate speed increases. For the 
second 5-minute bout, they were instructed to walk sideways towards their non-affected or 
stronger leg.  
 
 
Balance Domain 
This domain challenged participants by introducing various balance tasks that simulate real life 
activities participants may encounter. The goal was to determine the highest level of each 
activity they could perform, successfully repeating it three times within 5 minutes of training 
nonconsecutively per bout before moving on to the next level of difficulty within the 5-minute 
timeframe. For all nine challenges, one challenge bout trained with one leg leading and the next 
bout trained with the opposing leg leading. The tasks were demonstrated prior to starting. 
 
Step onto Step: This simulated the act of walking up and down stairs in an environment. The 
participants were instructed to first step up with their right or left leg and the other leg following, 
and then back down leading with leg they stepped up with first. It was repeated as many times as 
needed within the 5-minute bout timeframe until 3 successful attempts were completed. The 
steps were progressively increased by 1-inch intervals following successful completion of the 
task without a loss of balance until 5 minutes was up.  
 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
10 
 
Forward Step Length: To determine the participants’ longest step, they were instructed to take 
the longest step they could leading with their right or left leg without losing their balance. It was 
repeated two more times. The longest step out of the three was used as the initial training goal. A 
laser beam was aligned with that distance and participants were instructed to use their right or 
left heel to pass the laser beam then bring the other leg to meet it ensuring that both heels pass 
the laser beam. Once the task was successfully completed 3x, the step length was increased by 1 
inch. If the participant failed to successfully complete the task, they continued to train at the 
longest step length until 5 minutes were up. 
 
Slippery Surface: Participants were instructed to step onto a slippery surface plate leading with 
their right or left foot then followed by the other foot to determine what level they were able to 
stay on the surface without sliding/slipping off. They were to attempt to hold the step for three 
seconds before stepping backwards off the surface leading with their right/left foot. Starting off, 
the slippery surface was set to an angle of 0. The level of slipperiness was increased by 1 until 
the task was successfully completed three times. Participants were trained at the level of 
slipperiness at which they could not hold on for three seconds three times.  
 
Stepping onto Foam: Similar to stepping onto step, participants stepped onto the foam leading 
with their right/left leg followed by the other leg and then stepped back down with the leading 
leg. The foam was progressively increased by two inches as long as participants successfully 
completed the task three times.  
 
Forward Perturbation: Participants stood comfortably in the KA device with their eyes facing 
forward and walked at CWS. Forward perturbation was introduced (default of 0.48 peak velocity 
and 0.40 distance) by the device so that participants were pushed at the waist and instructed to 
hold their balance without taking a step. If a step was needed, it was done with the designated 
foot used for the bout training (right or left). After taking the step, they returned their foot back 
to the staring position. The perturbation was gradually increased (0.1 increments) after three 
successful attempts to push the participants harder until they were forced to take one and then 
two steps. The goal was to train participants at the level at which they needed to take two steps to 
recover their balance until they were able to take only one step.  
 
Backwards Perturbation: Similar to forward perturbation, participants stood comfortably in the 
device with their eyes forward and walked at CWS. They were pulled backward at the waist and 
instructed to try to hold their balance without taking a step. Only one step was required if a step 
was needed to catch their balance. It was to be taken with the designated foot used during bout 
training and returned to the starting positon. The level was increased after the defined successful 
attempts. Training was conducted at the level at which they took more than one step until they 
were able to take only one step.   
 
Forward Reach: Participants stood straight and tall in the device with eyes facing forward and 
one foot behind the other (feet are foot length apart with front foot ahead of back foot). They 
were instructed to ball their non-paretic hand into a fist and use it to reach forward as far as they 
could without losing their balance. They were to touch a target located in front of them with their 
fist. Upon touching the target, they were to stand up as quickly as they could without losing their 
balance. The distance of reach was determined, and the forward reach was repeated two more 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
11 
 
times. With three successful attempts, the target was moved an inch out for the next level, and 
participants were trained at the farthest distance reached. It was repeated with both feet in front 
of them.  
 
Sit to Stand: The goal for this challenge was to have the participant stand up from the lowest seat 
level possible without a loss of balance or the aid of their hands for support. They were to sit 
down on a step with their right/left foot in front of the other and stand without using their hands 
for support or changing their feet positon. Three successful repetitions resulted in lowering the 
seating distance by 1-inch increments until failure until the participant fails to complete 3 
repetitions. Participants were then trained at that level. 
 
Hurdle: Participants’ step height was first determined. They were instructed to step over the 
hurdle with their right/left leg then bring the other leg over to meet it. Step height was increased 
by increments of one inch until participants were unable to clear the hurdle height. Training was 
conducted at the highest height reached until three successful clearance attempts were attained 
before increasing the height by 1-inch for the next level.  
 
Stepping Domain 
Participants were trained on stepping if they came into the study with a very low level of walking 
ability whereby they were unable to complete the assessments. They were trained on taking steps 
in the KA device during the training sessions. After two weeks of training, an assessment will be 
attempted. If they were not able to complete the assessment, then they returned to step training; 
otherwise, they moved forward with the appropriate training domain as dependent on the 
assessment scores. Notice the expected progression of standing levels within the standing 
category as indicated in Fig 1. Because taking steps were often a challenge for participants, they 
may require the assistance of the research assistant to give them a push forward to initiate or 
increase steps taken using the KA force sensor or joystick mode as well as to help participants 
get into their target HR zone.  
 
Assessments 
Participants were assessed at biweekly intervals during the 10-week training period by a graduate 
research assistant to determine what training was to be conducted for a two-week period (Table . 
The first assessment was conducted on the second visit (after PT initial evaluation) to determine 
what training domain to begin with. There were six assessments in total (initial, end of week 2, 
end of week 4, end of week 6, end of week 8, and final – end of week 10). The following 
assessments after the first, evaluated participants beginning with the highest level achieved in the 
previous assessment for each domain. 
 
Table 3. Biweekly Targeted Assessment Domains 
Assessment Domain 
Instruction 
Performance Measure 
Comfortable walking speed 
(CWS) 
“Walk at your comfortable walk 
speed.”  Participants walk a 
total of 10m while achieving 
steady state speed. 
Average meters/sec 
Strength 
“Walk as fast as you can against 
the resistance.”  Participants 
Max resistance calculated 
by extrapolating the 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
12 
 
first walk against 5 lbs 
resistance and then researcher 
adds 1 lb per each 0.1 m/s 
attained until the participant 
cannot achieve 0.2 m/s. 
predicted resistance value 
at which the participant 
would not be able to move 
the treadmill belt. 
Dynamic Balance:  
 
1. Forward Reach 
 
 
 
 
 
 
 
 
2. Forward Step with 
Perturbation  
 
 
 
 
 
 
 
3. Step Up Test 
 
 
1. “Reach with non-paretic 
hand balled into a fist 
towards target while 
facing forward and 
bending at the waist” 
 
 
 
 
2. Forward perturbation 
during forward walking 
at CWS without losing 
balance and steadying 
oneself with only one 
step  
 
 
 
3. Using involved limb to 
step up on a step with 
progressive height 
increases without loss of 
balance  
 
 
1. Initial positon of 
outstretched fist of 
self-determined 
reach; final 
successful position 
(i.e., farthest 
distance reached) 
 
 
2. Max perturbation 
treadmill belt 
displacement; Max 
speed at max step 
length 
 
 
 
 
3. Max height when 
leading with the 
involved limb 
 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
13 
 
Locomotor Challenge:  
 
1. Max Step Length 
 
 
 
 
 
 
 
2. Narrow Stepping 
 
 
 
 
 
 
 
3. Walking with 
Backward 
Perturbation 
 
 
1. Participants were to take 
long steps towards a 
laser beam target (heel 
strike past laser beam) at 
their CWS; Progressive 
increase in distance by 1 
inch 
 
2. Participants were to 
walk at their CWS 
within a laser beam 
target of certain widths, 
which progressively 
narrowed if successful at 
the previous width target 
 
3. Participants walked at 
CWS. With introduction 
of perturbation, they 
were to catch themselves 
without a loss of 
balance. If successful, 
perturbation was 
successfully increased 
until failure; Initial 
assessment setting of 
perturbation was 0.48 
m/s initial speed and 0.4 
m as distance 
 
 
1. Position of final 
successful attempt; 
Total step length 
(final-initial)  
 
 
 
 
2. Width between feet 
(right light guide 
position and left 
light guide 
position) 
 
 
 
3. Max step length; 
Max speed at max 
step length 
Maximum Walking Speed 
Participants started walked at 
the fasted speed attained during 
the 10-meter walk test done 
within the device + 0.2 m (if 
first assessment) 
 
Progressive increase in speed of 
0.2 m until failure 
Speed of failure; Final 
successful walking speed 
(speed of failure – 0.2) 
Aerobic Endurance  
Stages 1 – 10 (1 min/stage) 
 
Participants were to walk at 
targeted deadband magnitudes 
of resistance (lbs.) per stage  
Test termination time; 
stage of test at termination 
 
Scoring the Assessments 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
14 
 
Scoring for each domain of the assessment categorized performance as levels 0 to 3 (0 – basic, 1 
– developing, 2 – competent, and 3 – expert). The participant’s lowest scored domain was their 
targeted training for the following two weeks. Within domain where multiple activities were 
assessed, the scores of were averaged to obtain an overall score. In the event of a tie of scores 
between domains, the domain not previously trained was targeted. It was also possible for 
participants to remain training at the same domain after each round of assessment based on 
scoring. Figure 2 shows detailed scoring breakdown for the assessments.  
 
 
Figure 2. Assessment Scoring Sheet 
 
Pt - participant, FR - forward reach, BW - body weight, PUSH – forward perturbation, PULL - 
backward perturbation 
 
 
Statistical Analysis Plan: 
Statistical analysis will be performed using Repeated measures ANOVA (subject x pre/post). 
Primary outcome measures will be pre vs post changes in BBS (primary balance measure), in the 
10m walk test speed, and 6 minute walk test distance. Secondary measures will be pre vs post 
changes in the Stroke Impact Scale (SIS) – Mobility Score, and the ABC.  A significance level of 
p<0.05 will be used to determine statistical significance. 
 
 
 
 
 
 
 
 
 
Level
Sit-stand
Standing
Stepping
Walking
Strength
Speed
Endurance
Balance
Locomotor Challenge
0: Basic
Pt requires >50% BW 
assistance (standard 
ht)
Pt requires >50% BW 
assistance (standing 
mode)
suspended stepping 
mode (assistance with 
advancing one or 
more legs)
Pt requires BW 
assistance (walking 
mode)
max force value <10 
lbs
top speed of <0.5 m/s
unable to complete 
1st 2 mins
FR=not > than initial 
reach; PUSH<.40 m 
AND 0.48 m/s; STEP 
UP= 1 in or less
STEP LENGTH 2 in or 
less; PULL<.40m AND 
.48 m/s; NARROW >3 
shoe widths
1: Developing
Pt requires 1% – 50% 
BW assistance 
(standard ht)
Pt requires 1% – 50% 
BW assistance 
(standing mode)
suspended stepping < 
0.5 m/s (no assistance 
with leg 
advancement)
Pt requires does not 
require BW assistance  
<0.5 m/s (walking 
mode)
max force value <14 
lbs
top speed of <1.0 m/s 2 mins - 4 mins
FR=2 in or less beyond 
initial reach; PUSH 
between .40 - .59 m 
AND 0.48 -.74 m/s; 
STEP UP between 2 - 5  
in.
STEP LENGTH 
between 3 and 6 
inches; PULL between 
.40 - .59 m AND >0.48-
.74 m/s; NARROW  
between =2 shoe 
widths to 3 shoe 
widths
2: Competent
Pt does not require 
assistance (standard 
ht)
Pt does not require 
assistance (standing 
mode)
suspended stepping < 
1.0 m/s (no assistance 
with leg 
advancement)
Pt requires does not 
require BW assistance  
<1.0 m/s (walking 
mode)
max force value <26 
lbs
top speed of <2.0 m/s 4+ mins - 8 mins
FR between 3 -6 in 
beyond initial reach; 
PUSH between .60 - 
.80 m AND 0.74 -.90 
m/s; STEP UP between 
6-10  in.
STEP LENGTH 
between 7 and 10; 
PULL between .60 - 
.80 m AND .74-.90 
m/s; NARROW 
between <2 shoe 
widths to >1 shoe 
widths
3: Expert
Pt does not require 
assistance (>4 in. 
lower than standard 
ht)
Pt does not require 
assistance (>6 with 
walking mode)
suspended stepping > 
1.0 m/s (no assistance 
with leg 
advancement)
Pt does not require 
assistance > 1.0 m/s
max force value >=26 
lbs
top speed of > or = 2.0 
m/s
8 mins +
FR > 6 in. beyond 
initial reach; PUSH > 
.80 m AND .90 m/s; 
STEP UP >10  in.
STEP LENGTH > 10 in.; 
PULL > .80 m AND .90 
m/s; NARROW =1 
shoe width

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
15 
 
References 
 
Billinger S, A.R., Bernhardt Julie, Eng Janice,, Physical Activity and Exercise Recommendation 
for Stroke Survivors: A statement for health care professionals from the American Heart 
Association/American Stroke Association. Stroke American Heart Association, 2014. 
PMID: 24846875, DOI: 10.1161/STR.0000000000000022 
Karvonen, J. and T. Vuorimaa, Heart rate and exercise intensity during sports activities. Practical 
application. Sports Med, 1988. 5(5): p. 303-11. PMID: 3387734 
Tabet, J.-Y., et al., Determination of exercise training heart rate in patients on β-blockers after 
myocardial infarction. European Journal of Cardiovascular Prevention & Rehabilitation, 
2006. 13(4): p. 538-543. PMID: 16874142 DOI: 10.1097/01.hjr.0000209813.05573.4d 
Noble, B.J., et al., A category-ratio perceived exertion scale: relationship to blood and muscle 
lactates and heart rate. Medicine and science in sports and exercise, 1983. 15(6): p. 523-
528. PMID: 6656563 
Borg, G., P. Hassmén, and M. Lagerström, Perceived exertion related to heart rate and blood 
lactate during arm and leg exercise. European journal of applied physiology and 
occupational physiology, 1987. 56(6): p. 679-685. PMID: 3678222 
Pohl, P.S., et al., Influence of stroke-related impairments on performance in 6-minute walk test. 
Journal of rehabilitation research and development, 2002. 39(4): p. 439. PMID: 
17638141 
Bohannon, R.W., Comfortable and maximum walking speed of adults aged 20—79 years: 
reference values and determinants. Age and ageing, 1997. 26(1): p. 15-19. 
PMID:  9143432 
Mehrholz, J., et al., Predictive validity and responsiveness of the functional ambulation category 
in hemiparetic patients after stroke. Archives of physical medicine and rehabilitation, 
2007. 88(10): p. 1314-1319. PMID: 17908575 DOI: 10.1016/j.apmr.2007.06.764 
Folstein, M.F., S.E. Folstein, and P.R. McHugh, "Mini-mental state". A practical method for 
grading the cognitive state of patients for the clinician. J Psychiatr Res, 1975. 12(3): p. 
189-98. PMID: 1202204 
Blum, L. and N. Korner-Bitensky, Usefulness of the Berg Balance Scale in Stroke 
Rehabilitation: A Systematic Review. Physical Therapy, 2008. 88(5): p. 559-566. PMID: 
18292215 
An, S., et al., Validity of the Original and Short Versions of the Dynamic Gait Index in Predicting 
Falls in Stroke Survivors. Rehabilitation Nursing, 2016: p. n/a-n/a. PMID:  
 

PROTOCOL: MACHINES ASSISTING RECOVERY FROM STROKE 
 
 
 
16 
 
Powell, L.E. and A.M. Myers, The activities-specific balance confidence (ABC) scale. The 
Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 1995. 
50(1): p. M28-M34. PMID: 27278685 
 
Yesavage, J.A., et al., Development and validation of a geriatric depression screening scale: a 
preliminary report. J Psychiatr Res, 1982. 17(1): p. 37-49. PMID: 7183759 
 
Michaelsen, S., Stroke Impact Scale, in Encyclopedia of Quality of Life and Well-Being Research, 
A.C. Michalos, Editor. 2014, Springer Netherlands: Dordrecht. p. 6365-6368.