1. My project is unique because it is used a hybrid
methodology including a quantitative research study
(Part 1), a qualitative research study (Part 2), and an
engineering project (Part 3). The culmination of my
work, the development of the CFM walker, will
improve outcomes for patients recovering from open
heart surgery, critical illness, and certain orthopedic
conditions.
Engineering a Clinical Force Measuring Walker (CFM) for Patients with
Restricted Upper Extremity Weight Bearing (UEWB)
Ansel LaPier, Central Valley High School, Spokane Valley, WA, USA
Conducted a secondary data analysis to
determine if: 1) patients are not able limit UEWB to
< 10 lb (4.5 kg) and 2) feedback training with a
walker instrumented to measure force is effective.
RESULTS: Study findings suggest that older patients
are less able to modulate but better able to reduce
UEWB after feedback training than younger
patients. Established need for and efficacy of
a force measuring walker.
Fabricated force measuring walker prototype that
could be used by patients with restricted UEWB in
clinical settings
Clinical Force Measuring Walker v1.0
Performed a qualitative research study to
garner information from rehabilitation
professionals regarding the structure and function
of the first prototype, CFM Walker v1.0.
Used engineering design and testing process
to modify the CFM Walker v1.0 based on
qualitative data and previously defined design
criteria / constraints and testing protocol.
RESULTS: All testing criteria were met. The
innovative Clinical Force Measuring Walker
v2.0 will help patients with restricted UEWB during
post-fracture bone ossification to optimize recovery
by promoting safe timely return to function.
RESULTS: Suggested revisions were to integrate
force transducers in handles, create a simplified
feedback display with upper limit alarms,
streamline the device, and modify the attachemnts.
Project ID: HS-TMED-0087?

2. Introduction – Background, Previous Designs, & Purpose / Goal
 Background & Review of Literature
 Patients recovering from bone disruption due to trauma or
surgery need to limit use of their upper extremities during bone
healing often to < 10 lb (4.5 kg).3,4
 Common patient diagnoses that require post-fracture (iatrogenic
or traumatic) bone ossification include cardiac surgery via
median sternotomy (Figure 1), total shoulder arthroplasty, and
upper extremity bone fractures.5
 Limiting UEWB is thought to minimize shear force and
movement between the bone halves to protect callus formation
and osteogenesis (Figure 2).3,6,7
 Restricting arm use often limits patient functional independence
which can contribute to longer hospital stays and greater need
for care after hospitalization. Therefore, appropriate arm use is
important for timely return to function.8,9
 Little is known about how much UEWB force actually occurs
when older patients attempt to use < 10 lb; so their ability to
safely resume activity and use of a walker is unknown.10-12
 Previous studies have found that patients are not good at
limiting leg weight bearing.13-15
 A method to objectively measure UEWB force while patients use
a walker is needed.
 Currently there are no walkers for use with patients to provide
UEWB force feedback.
 Previous Designs & Limitations
Existing walkers instrumented to measure UEWB
force are only appropriate for research applications
and have many limitations that preclude their use
with patients including they:
1) have complicated force displays positioned remotely
from the walker.10-12,16
2) use sensors placed in the walker legs, not the handles.17
3) do not display data for the patient and therefore cannot
be used for feedback training.18,19
4) are bulky, expensive, and not built on a clinical walker
frame (not the same as a patient would use).20
 Current Project Purpose / Goal
PART 1: Secondary Data Analysis
The primary purposes of this secondary data analysis were
to determine if during functional mobility, older patients
less accurately estimated using < 10 lb of arm weight
bearing force and if they were able to improve their
accuracy to the same degree following feedback training
compared to younger patients.
PART 2: Qualitative Research Study
The purpose this study was to obtain qualitative critiques
from healthcare professionals about my first CFM Walker
prototype (v1.0) to allow revisions and refinement of the
mechanical device and user interface.
PART 3: Engineering Project
The engineering goal for this project was to design,
construct, and test a walker for patients who need to limit
UEWB (< 10 lb or 4.5 kg) to prevent excessive bone stress
during post-fracture ossification.
Figure 2. Bone Healing Mechanisms.2
Figure 1. Median Sternotomy.1

3. Figure 5. CFM Walker v2.0 Components: 1) Chest tube
reservoir mounting bracket, 2) Integrated force transducers,
3) Electrical components, 4) Force display mounting
bracket, 5) Urinary collection bag hook, 6) Oximeter holder.
1 1
2
2 2
3
4
5 5
6
Figure 4. CFM Walker v1.0 Components: 1) Chest tube reservoir plate,
2) Color coded walker legs, 3) Oxygen tank mounting bracket, 4) Ergonomic soft
handle grips, 5) Tablet adjustable mounting arms & waterproof cases, 6) Urinary
collection bag hook, 7) Foley Catheter S-hook.
First
Prototype
CFM
Walker
Research
ONLY
Instrumentation
Figure 3. Research Device Components:
1) Exterior mounted force dynamometers,
2) Remote force display tablets, 3) Manual
buzzer, 4) Force output display.
*Can only be used in a laboratory setting
1
2
3
Introduction – Previous Research
 Previous Research Study #110
 Established that young subjects (18-40 years old) are not able to
accurately estimate using < 10 lb UEWB during functional mobility.
 Developed a feedback training protocol and demonstrated its efficacy
for improving subjects’ ability to modulate UEWB and Pectoralis
Major Muscle activation.
 Previous Research Study #211
 Corroborated findings of previous study in a cohort of older subjects
(60-85 years).
 Identified metrics predictive of excessive UEWB during functional
tasks including handgrip strength, static and dynamic balance, health
status, and body mass index.
 Current Research Project
PART 1: Secondary Data Analysis
New statistical analyses conducted to compare UEWB and Pectoralis
Major Muscle activation in younger vs. older subjects using data pooled
from the previous research studies.
PART 2: Qualitative Research Study
Novel qualitative study completed using a phenomenological approach
interviewing rehabilitation professionals regarding the initial CFM
Walker prototype (v1.0).
4
Second
Prototype
CFM
Walker
PART 3: Engineering Project
Development of a new device that can be used by patients in clinical settings. The
instrumentation (Figure 3) previously used to collect force data in a laboratory setting
is not appropriate for clinical use because it has externally mounted force transducers,
remote displays, a manual buzzer, and complicated, difficult to see force output.
CFM Walker 1.0 Prototype Component Summary:21,22 Figure 4
 Tablet water-proof covers to allow for disinfecting (Fig 4.5)
 Tablet clamp mounts so display screens not remote (Fig 4.5)
 Grips added to dynamometer handles to improve ergonomics (Fig 4.4)
 Medical equipment attachments added: Oxygen tank (Fig 4.3), Chest tube
reservoir (Fig 4.1), Urinary collection bag (Fig 4.6), Foley Catheter (Fig 4.7)

4. Subjects *Pooled data
 Young: 18-40 years (n=26)
 Old: 60-85 years (n=39)
Independent Variables
 Standard Walker Ambulation
 Wheeled Walker Ambulation
 Sit to Stand Transfers
 Stand to Sit Transfers
Dependent Variables
 Arm Extremity Weight Bearing Force
• Measured using a walker (Deluxe Folding, Drive Medical) instrumented with digital
dynamometers (Jamar Smart, Performance Medical) wirelessly connected to tablets
(Kindle Fire 10, Amazon).
• Peak force in both upper extremities was simultaneously recorded.
 Pectoralis Major Muscle Electromyography (EMG)
• Measured using bipolar electrodes (1x10 mm Ag-AgCl) and a data logger with
processing software (DataLOG Multisensor System, Biometrics Ltd, Newport, UK).
• Root-mean-square was used to process data and values were expressed relative
to a reference maximal voluntary isometric contraction.
Feedback Training Intervention
 Sustained pressure in standing with visual feedback for 30 sec x 2 trials
 Ambulation with auditory feedback for 30 sec using both walkers
 Sustained pressure in sitting with visual feedback for 30 sec x 2 trials
 Sit to stand using the walker turned backward as chair arm rests with
auditory feedback for 30 sec x 2 trials
Methods - Secondary Data Analysis Table 1. Two-way ANOVA Statistics for UEWB Data
Statistical Analyses (P < 0.05)
 ANOVA (2-way without replication) Age (young
vs old) X feedback (pre- vs post-) Table 1 & 2
 t-Tests (2-sample assuming equal variances)
Pre-to-post difference in young vs old Table 3 & 4
 Based on effect size (moderate) & sample size
(n = 65), statistical power was sufficient (> 80%).
Table 2. Two-way ANOVA Statistics for EMG Data
Table 3. Two-tailed t-Test Statistics for UEWB Data Table 4. Two-tailed t-Test Statistics for EMG Data
Factor SS df MS F P-value
Age 0.588 63 0.0093 5.683 4.05E-11
Feedback 0.037 1 0.0367 22.364 1.31E-05
Error 0.103 63 0.0016 Standard Walker
Age 0.757 63 0.0120 6.122 7.50E-12
Feedback 0.014 1 0.0143 7.268 0.00899
Error 0.124 63 0.0020 FW Walker
Age 1.242 61 0.0204 4.026 8.94E-08
Feedback 0.125 1 0.1246 24.639 5.87E-06
Error 0.308 61 0.0051 Sit to Stand
Age 1.841 62 0.0297 11.466 2.22E-18
Feedback 0.108 1 0.1080 41.709 1.85E-08
Error 0.161 62 0.0026 Stand to Sit
Old Young Old Young Old Young Old Young
Variance 0.0034 0.0008 0.0038 0.0003 0.0156 0.0152 0.0041 0.0039
Observations 39 26 39 26 37 26 38 26
df 63 63 61 62
t Stat 3.3202 3.9081 2.5499 1.6248
P(T<=t) 0.0007 0.0001 0.0067 0.0546
t Critical 1.6694 1.6694 1.6702 1.6698
Standard
Walker
FW
Walker
Sit
to
Stand
Stand
to
Sit
Old Young Old Young Old Young Old Young
Variance 196.03 56.65 62.93 14.28 136.80 39.59 150.84 41.90
Observations 39 25 38 26 39 26 38 24
df 62 62 63 60
t Stat 2.4351 2.9577 4.1362 3.0027
P(T<=t) 0.0089 0.0022 5.3E-05 0.0019
t Critical 1.6698 1.6698 1.6694 1.6706
Standard
Walker
FW
Walker
Sit
to
Stand
Stand
to
Sit
Factor SS df MS F P-value
Age 9794.2 63 155.5 1.77 0.012
Feedback 6125.2 1 6125.2 69.91 8.34E-12
Error 5519.5 63 87.6 Standard Walker
Age 3401.7 62 54.9 1.64 0.027
Feedback 1329.3 1 1329.3 39.64 0.000
Error 2079.1 62 33.5 FW Walker
Age 14445.3 63 229.3 3.12 5.80E-06
Feedback 6451.1 1 6451.1 87.78 1.50E-13
Error 4629.9 63 73.5 Sit to Stand
Age 12541.1 60 209.0 3.16 7.56E-06
Feedback 5796.0 1 5796.0 87.70 2.41E-13
Error 3965.4 60 66.1 Stand to Sit
Standard
Walker

5. Subjects
 Healthcare professionals with
rehabilitation & critical care
experience (> 6 months)
Data collection
 Phenomenological approached used
to describe, in depth, the common
characteristics of a shared
experience treating hospitalized
patients23,24
 Open-ended questions used to
garner feedback on walker
prototype (Figure 4)
 Slides with photographs/video clips
of the walker and questions used as
shown in Figure 8
 Interviews transcribed for coding
and analysis
Data analysis
 Identified key significant statements
/ phrases for each category
 Sorted statements into groups that
emerged as meaningful themes
 Generated rich descriptions of
perceptions corresponding with
each theme using participants’ exact
words and phrases
 Continued data analysis using an
iterative process until saturation
was achieved
Process repeated with 2nd
prototype – CFM Walker v2.0
Figure 6. Slides used during qualitative data
collection with videos to show the walker prototype.
Methods –
Qualitative Research

6. Table 5. Design Elements, Criteria / Constraints, and Design Testing Plan. *3 Trials
Methods - Engineering Project
Design Elements Criteria / Constraints Design Testing Plan
Vertical force
measuring capability
Force measurements 90%
accuracy in 1-20 lb (0.5 - 9.1)
kg range
Obtain readings using push dynamometer1 on
each handle within correct range: Green < 7 lb,
yellow 7-10 lb, red > 10 lb (30 trials)
Ergonomic handles Handle diameter 3-6 cm
*Measure circumference of handles in mm
calculate diameter
Simple visual &
auditory feedback
with alarms
1) Display readable from 1 m
with upper limit alarm
2) Buzzer audible from 1 m with
upper limit alarm
*Measure distance in 50 cm increments up to 3
m that subjects ages 18-83 year old (n = 6) can:
1) see visual display screen and
2) hear auditory signal output.
Streamlined, stable,
& maneuverable
frame
Width < 66 cm
Depth < 63 cm
*Measure using a caliper device and tape
measure with 1 mm increments
Lightweight
construction
Total weight < 6 kg
Weigh walker with & without attachments using
scientific scale2
Minimal drag
Horizontal push-pull resistance
(Drag) < 2 kg
Measure horizontal resistance using a push-pull
force dynamometer1 over 155 cm on solid
surface with 4 wheel-types3 (10 trials each)
Adjustable height
handles
Appropriate for patients
1.6-1.8 m tall
*Measure top of handle height using a caliper
device and tape measure with 1 mm increments
Ability to disinfect
1) All components nonporous
2) Electrical components
covered / water resistant
1) Create checklist of component materials to
categorize as nonporous vs porous
2) *Assess functionality (yes/no) after spraying
electrical components with 100 cc of water
Affordable cost Components total cost < $500 Keep a detail itemized list of component costs
1Mark-10 CG High capacity digital force gauge, 1,000 lb tensile or compressive force (Mark-10 Corporation, Copiague, NY); 2CAS
SW-50 SW-1W Series Washdown Portion Control Bench Scale, 50lb Capacity, 0.01lb Readability (CAS Corporation, East Rutherford,
NJ); 3Walker Wheels Standard 5” (Drive Medical, Post Washington, NY)
Figure 8. CFM Walker v2.0. 1) Integrated force
transducers, 2) Force output electronic components,
3) Mounting bracket, 4) Oximeter attachment, 5)
Urinary collection bag attachment, 6) Foley Catheter,
7) Chest tube reservoir attachment, 8) Chest tube.
❶ ❷ ❶
❺
❸
❹
❹
❻
❽
❼
❶ ❷
❺
❻
❽
❼
❸ ❹

7. Results - Secondary Data Analysis
 UEWB Results (Figure 6A &7A)
 Significant differences in UEWB between groups (older vs younger) and trials (pre- vs post-feedback).
 Significantly greater improvement in UEWB force in the older compared to younger subjects.
 Pectoralis Major Muscle EMG Results (Figure 6B & 7B)
 Significant differences in UEWB force and PM Muscle EMG between groups (older vs younger) and trials (pre- vs post-feedback).
 Significantly greater improvement in UEWB force and PM muscle EMG in the older compared to younger subjects.
These results were published in the journal
of Physical Therapy and Rehabilitation.12
Figure 10. Arm weight bearing force (A) and pectoralis major muscle
electromyography (B) data (mean + SD) before and after feedback training for young
and old groups.
Figure 9. Arm weight bearing force (A) and pectoralis major muscle electromyography
(B) improvement after feedback training data (mean + SD) for young and old groups.
Std = standard; FW = front wheeled
Std = standard
FW = front wheeled
*Significant difference young vs old (P < 0.05)
†Significant difference pre- vs post-feedback training (P < 0.05)
*Significant difference young vs old (P < 0.05)

8. Figure 11. CFM Walker v1.0 Revisions:
 External dynamometers replaced with thin
film force sensing resistors placed under
integrated handgrips
 Tablets replaced with force display and buzzer
created using an Arduino system housed in a
water-proof case
 Medical equipment attachments:
X Oxygen tank – REMOVED cage
X Foley catheter – REMOVED S-hook
X Walker legs – REMOVED color-coding
Chest tube reservoir - MODIFIED bracket
Urinary collection bag - MODIFIED swivel hook
+ Oximeter - ADDED bracket
X
X
X
X X
X
+
Results - Qualitative
Research
Summary of Themes for CFM Walker v1.0
Chest Tube Reservoir Good location; Tube
adequately †protected; *Meets essential
features; May not work for all reservoir types; Improvements: higher
or with adjustable height, block swinging inward.
• Walker Legs Ideal combination: wheels only on front legs; Color-
coding not necessary; Improvements: needs to be disinfectable, back
leg “ski-like” gliders.
• Oxygen Tank Location Issues: tipping forward, regulator
protection; *Meets essential features: Would not fit most common
portable oxygen tanks; Improvements: remove bracket, transport
tank separately.
• Force Transducers Like large diameter grips; Handles too wide;
2 sets of hand grips confusing; Improvements: needs to be
disinfectable, integrated transducers ideal to reduce width/weight
and simplify build.
• Display Mounts Location Issues: tipping forward, obstruct
patient / provider view; *Meets essential features; Good
adjustability; Improvements: single unit instead of 2, reduce weight.
• Display Interface Units in pounds good; Color-coded, graphical
information helpful; Visual feedback display too complicated and
small; Improvements: larger, simpler force output, alarm signals.
• Urinary Catheter & Collection Bag Good location; †Catheter
adequately protected; *Meets essential features; Improvements:
block swinging inward, remove hook for catheter.
*Essential features: no gait obstruction, device stable, intuitive
function, and user-friendly.
†Adequately protected from touching the ground and from becoming
kinked, tangled, or dislodged.

9. Table 9. Push-Pull Horizontal Resistance (kg)
Figure 12. Arduino circuit diagram.
Table 7. Force Accuracy
RIGHT LED LEFT LED
1.0 G 2 G
1.2 G 2.2 G
1.6 G 2.6 G
2.0 G 3.2 G
2.2 G 4 G
2.4 G 4.4 G
3.0 G 4.6 G
3.4 G 5 G
3.6 G 5 G
4.2 G 5.6 G
4.4 G 6.2 G
4.8 G 7 G
5.0 G 7.2 G
5.8 G 7.6 Y
5.8 G 7.8 Y
6.2 G 8.4 Y
6.4 G 8.4 Y
7.0 Y 8.6 Y
8.0 Y 8.8 Y
9.2 Y 9.2 Y
9.2 Y 9.6 R
9.8 R 9.8 R
10.0 Y 10.4 R
10.6 R 10.8 R
11.6 R 12.4 R
11.8 R 14.0 R
13.2 R 15.6 R
15.4 R 16.2 R
17.4 R 17.6 R
23.8 R 20..0 R
Error% 10.3% 10.3%
Results -
Engineering Project
*Significantly > Push P < 0.05
ᶧSignificantly > 5” Wheel
Design Elements CFM Walker v2.0
Vertical force measuring
capability
Accuracy = 90% MET
Ergonomic handles Diameter = 3.5 cm MET
Simple visual & auditory
feedback with alarms
1) Visual display > 3 m MET
2) Auditory signal > 3m MET
Streamlined, stable, &
maneuverable frame
Width = 63.0 cm MET
Depth = 50.2 cm MET
Lightweight construction No MD = 3.9 kg & With MD = 5.6 kg MET
Minimal drag (Push-Pull)
No MD = 0.5 - 0.9 kg MET
With MD = 0.8 - 1.2 kg MET
Adjustable height handles Patient height = 1.49-1.95 m MET
Ability to disinfect
1) Nonporous Yes MET
2) Water resistant Yes MET
Affordable cost Component Cost = $238 MET
5" Planar Wheel 5" Swivel Wheel 3" Planar Wheel 3" Swivel Wheel
Trial # Push Pull Push Pull Push Pull Push Pull
1 0.7 1.3 0.6 1.0 0.8 2.4 0.9 2.1
2 0.7 0.8 0.8 1.6 0.7 1.8 1.0 1.8
3 0.8 1.0 0.6 1.4 0.9 2.4 0.9 2.6
4 0.7 0.9 0.6 1.7 0.8 1.7 1.1 2.7
5 0.8 1.1 0.9 1.6 0.8 1.8 1.1 2.5
6 0.8 1.4 0.7 1.4 0.8 2.2 0.9 2.2
7 0.8 1.5 0.8 1.2 0.8 2.3 0.8 2.2
8 0.8 1.1 0.7 1.8 0.8 2.5 1.1 2.2
9 0.7 1.2 0.9 1.2 0.8 2.0 0.9 2.3
10 0.8 1.2 0.8 1.4 0.8 2.0 1.1 2.1
Mean 0.76 1.15 0.74 1.43* 0.80 2.11*† 0.98 2.27*†
SD 0.05 0.22 0.12 0.25 0.05 0.29 0.11 0.27
Table 6. Summary of Engineering Testing Results.
Factor SS df MS F P-value
Wheel type 7.34 39 0.19 1.7 0.0487
Push-pull 16.93 1 16.93 153.5 4.2E-15
Error 4.30 39 0.11
Table 8. Two-way ANOVA Statistics for Drag
 Components and dimensions of
the CFM Walker are shown in
Figures 7 & 8
 The CFM Walker v2.0 met all
criteria / constraints – Table 6
 Force Accuracy – Table 7
 Push-pull Horizontal Drag – Table 9
 ANOVA Statistics – Table 8
 Rear leg gliders (3 types) did not
reduce drag so were not added
 Feedback Display
 Components – Figure 11
 Electrical Circuit Diagram – Figure 12

10. Discussion
Qualitative Research
Main themes that emerged from interviews
with rehabilitation professionals included:
 A CFM walker with integrated handles would
be clinically useful
 Streamlining attachments would help reduce
total weight, bulkiness, and surface area
 Some attachments for medical devices are
helpful; remove oxygen tank, add oximeter
 Simplify visual display and add auditory
warning signal
 Useful for a variety of patient populations
(median sternotomy, upper extremity
fractures, critically ill…)
Secondary Data Analysis
 Study findings suggested that patients are
not good at estimating UEWB < 10 lb,
especially older ones.
 Results also demonstrated that younger and
older patients can improve their ability to
modulate UEWB and Pectoralis Major
Muscle EMG with feedback training.
 This study established: 1) proof-of-concept,
2) need for a force measuring walker, and
3) efficacy of its use with feedback training.
Engineering Project
 The CFM Walker v2.0 met all the criteria /
constraints as outlined in Table 6, and
significantly improved the design and
function of the original prototype (Table 10).
 The major revisions that impacted
performance of CFM Walker v2.0 included
using thin film force sensing resistors (Figure
13) interfaced with a simplified Arduino-
based feedback system (Figure 11 & 16) and
adapting medical equipment attachments
(Figures 14, 15,17).
Future Directions
• Refine component fabrication
• Test with patient populations
• Perform RCT to assess better
patient outcomes with use25
• Modify for home use
Obtained Rehab
Professional Feedback
Engineered 2nd CFM Prototype Walker
Tested Engineering
Design Parameters
Yes
Meet all
criteria?
Fabricated 1st CFM Walker Prototype
No
Research Instrumentation
 The device used for previous
research could not be used by
patients in clinical setting.
 Therefore, I engineered a new
device, the CFM Walker, using
multiple steps (see Flowchart).
Figure 13. Thin film force
resistor under hand grips.
106
46
53 93
37
99
Figure 14. Attachment for oximeter.
Figure 15. Swivel hook for
urinary collection bag.
Figure 16. Force output
electronic components.
Figure 17. Attachment
for chest tube reservoir.
188
135
23
73
133
93
19
40
59
77
154
22
51
68
137
53
60
46
64
52

11. Design Elements Research Device CFM Walker v1.0 CFM Walker v2.0
Vertical force measuring
capability Accuracy = 82% Accuracy = 82% Accuracy = 90%
Ergonomic handles Diameter = 2.2 cm Diameter = 5.2 cm Diameter = 3.5 cm
Simple visual & auditory
feedback with alarms
Visual < 50 cm
Auditory NONE
Visual < 50 cm
Auditory NONE
Visual display > 3 m
Auditory signal > 3 m
Streamlined, stable, &
maneuverable frame
Width = 67.9 cm
Depth = 53.0 cm
Width = 67.9 cm
Depth = 53.0 cm
Width = 63.0 cm
Depth = 50.2 cm
Lightweight construction No MD = 7.2 kg
No MD = 8.4 kg
With MD = 13.0 kg
No MD = 3.9 kg
With MD = 5.6 kg
Minimal drag (Push-Pull) No MD = 1.4 - 2.0 kg
No MD = 1.4 - 2.0 kg
With MD = 1.4 - 2.0 kg
No MD = 0.5 - 0.9 kg
With MD = 0.8 - 1.2 kg
Adjustable height handles 1.76 - 2.06 m 1.76 - 2.06 m 1.49 - 1.95 m
Ability to disinfect
Nonporous Yes
Water resistant Yes
Nonporous No
Water resistant Yes
Nonporous Yes
Water resistant Yes
Affordable cost $1,359 $1,409 $238
Secondary Data Analysis:
Study results suggest that patients
are not good at estimating arm
force <10 lb and that feedback
training is effective. Use of an
instrumented walker and feedback
training would be beneficial in
clinical practice, especially with
older patients.
Qualitative Research:
Data from rehabilitation
professionals indicated that the
CFM walker with integrated handles
would be clinically useful.
Suggestions lead to modifications
including streamline components
and modifying, removing (oxygen
tank), and adding (oximeter)
medical device attachments.
Engineering Project:
The CFM Walker v2.0 meets
essential criteria for making it
feasible for patients who need to
limit UEWB to prevent excessive
bone stress during post-fracture
ossification.
Ultimately the CFM Walker v2.0
will improve outcomes for
patients recovering from open
heart surgery, critical illness, and
certain orthopedic conditions.
Conclusions
Table 10. Summary Illustrating the Evolution of the CFM Walker with Engineering Testing Results.
Results in BOLD indicate results where engineering criteria / constraints were met as defined in Table 5.

12. Figure Citations
1) Figure 1 from: www.medical-illustration.ch/single-post/2018/10/08/New-Illustrations-Cardiac-Surgery
2) Figure 2 modified from: https://slideplayer.com/slide/12857839/78/images/30/Steps+in+the+Repair+of+a+Fracture.jpg
Ansel LaPier Publications
10) LaPier A, Cleary K. Feedback training improves accuracy of estimating upper extremity weight bearing during functional tasks –
implications after open heart surgery. International Journal of Physiotherapy and Research. 2019;7(4):3163-3172. DOI:
10.16965/ijpr.2019.151 http://www.ijmhr.org/ijpr.7.4/IJPR.2019.151.pdf
11) LaPier A, Cleary K. Feedback training improves compliance with sternal precaution guidelines during functional mobility:
implications for optimizing recovery in older patients after median sternotomy. Applied Bionics and Biomechanics. 2021;Article ID
8889502:13 pages. doi.org/10.1155/2021/8889502 https://downloads.hindawi.com/journals/abb/2021/8889502.pdf
12) LaPier A, Cleary K. The influence of age and feedback training on ability to modulate upper extremity weight bearing force and
pectoralis major muscle recruitment while following sternal precautions. Physical Therapy and Rehabilitation. 2021;8:1.
dx.doi.org/10.7243/2055-2386-8-1 https://www.hoajonline.com/journals/pdf/2055-2386-8-1.pdf
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