iWalk Hands Free Crutch (HFC)

Effects of a Hands Free Crutch on Walking Stability During Gait

The proposed study evaluates the effects of a hands free crutch (iWalkFree, Inc.) on walking balance and stability compared to standard crutches. It is expected that the hands free crutch will provide better stability during walking on a level surface and better reported balance confidence compared to standard crutches. In this study, walking stability will be assessed using motion capture data from an infrared camera system with 12 mounted cameras surrounding a level walkway. Balance will be assessed through a self-reported activity-specific balance confidence (ABC) questionnaire. An improved understanding of the effects of the hands free crutch on gait may benefit the future prescription of ambulatory assistive devices. The proposed study may provide insight that can be used by physical therapists and other providers to select the ambulatory assistive device that best meets their patients' needs.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Device: BOOT; Device: HFC+BOOT; Device: SAC+BOOT; Device: HFC; Device: SAC

Detailed Description

The purpose of this study is to compare the hands free crutch (HFC) to standard axillary crutches (SACs) with and without a walking boot, using outcomes related to walking stability, balance confidence, patient preference, device comfort, and any reported pain while using the devices.

Healthy, able-bodied individuals will wear a walking boot to simulate a below knee injury or post-surgery condition during participation. They will maintain a non-weight bearing status while completing the 4 research conditions in randomized order: 1) BOOT, 2) HFC + BOOT, 3) SAC + BOOT, or 4) NONE.

Participants will complete 5 total sessions, with 4 biomechanics data collection sessions corresponding to the 4 conditions. At the first visit, participants will complete pre-consent screening and consent paperwork. Then they will be randomized to the 4 conditions above, and anthropometric (body height, weight/mass, leg length, shoe length and width) and demographic data will be collected. Participants will accommodate overnight to each of the 4 study conditions before testing. If participants are randomized to the NONE condition first, they will have the option of completing testing in that condition (no Boot) at the initial visit. The primary dependent measure is whole body angular momentum, an objective measure of walking stability.

Data will be collected using over 50 small reflective markers placed on the participants and the assistive devices, a computerized motion capture system and force plates embedded in the floor. The force plates capture ground reaction forces which will be used to calculate joint moments for interpretation of angular momentum data. The motion capture system will be used to evaluate joint and segment kinematics and temporal-spatial data to characterize the gait pattern in each condition and calculate angular momentum.

The second purpose of this research study is to determine the effect of crutch use on participant reported balance confidence and device preference. A validated balance confidence questionnaire and participant satisfaction, comfort and preference will be used to compare between conditions. A numerical pain rating scale (0-10) will be used to assess for any reported pain in all of the conditions.

The third purpose of this research is to determine the effect of crutch (HFC and SACs) and boot (with and without) use on walking stability as measured by whole body and segmental angular momentum during gait. Two additional conditions are added to address this purpose (HFC NO BOOT and SAC NO BOOT), resulting in a total of 6 research conditions:

1) BOOT, 2) HFC + BOOT, 3) SAC + BOOT 4) NONE, 5) HFC NO BOOT, 6) SAC NO BOOT The HFC NO BOOT condition will be evaluated at the end of the HFC + BOOT session, and the SAC NO BOOT condition will be evaluated at the end of the SAC + BOOT session to stay within the fiscal and logistical constraints of the project. Previously described methods will be used.

Ultimately, this study could assist physical therapists and other providers in the clinical prescription and application of such devices.

• Study Type: Interventional
• Enrollment (Actual): 21
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Iowa
    • Iowa City, Iowa, United States, 52242
      • Human Performance and Clinical Outcomes Lab, The University of Iowa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male or Female
• Ages: 18 - 45
• Height between 5'2" and 6'6"
• Foot size that corresponds to available walking boots
• Healthy individuals without current complaint of lower extremity pain, spine pain, open wounds or active infection
• Full active pain free range of motion of the bilateral upper and lower extremities and spine
• Able to hop without pain
• Able to perform a full squat without pain
• Able to walk up and down a flight of stairs at normal walking speed without using the hand rail
• Able to stand on one leg for at least 30 seconds
• Able to read and write in English and provide written informed consent

Exclusion Criteria:

• Weight greater than 270 lbs
• BMI greater than 35
• Maximum thigh circumference at top of the leg greater than 28"
• Prior medical or neuromusculoskeletal disorders that have limited their participation in work or exercise in the last 6 months
• Prior lower extremity injury proximal to the ankle requiring surgery or limiting function for greater than 6 weeks
• Prior back pain that recurs or has limited activities for greater than 6 weeks
• Diagnosed moderate or severe brain injury
• Diagnosis of a physical or psychological condition that would preclude testing (e.g. cardiac condition, clotting disorder, pulmonary condition)
• Uncorrected visual or hearing impairment(s)
• Require use of an assistive device
• Pregnancy - Per participant self-report. Due to the expected small number of pregnant individuals, and resulting inability to account for its effect on resulting outcomes, participants will be withdrawn from the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Arm 1. NONE; Participants will be tested while wearing no boot and no assistive device.
Experimental: Arm 2. BOOT; The first intervention condition tested is a walking boot only on the subject's right lower extremity.	Device: BOOT; A walking boot is a common type of brace/boot that restricts ankle and foot movement.; Other Names: Walking Boot; CAM Boot; Controlled Ankle Motion Boot
Experimental: Arm 3. HFC+BOOT; The second intervention condition tested is a Hands Free Crutch (HFC) with the walking boot, both worn on the subject's right lower extremity.	Device: HFC+BOOT; The Hands Free Crutch (HFC) by iWalkFree, Inc. is a novel, ambulatory assistive device that prevents foot and ankle loading while also allowing free use of the arms and hands. A walking boot is a common type of brace/boot that restricts ankle and foot movement.
Experimental: Arm 4. SAC+BOOT; The third intervention condition tested is standard axillary crutches (SAC) with the walking boot worn in non-weight bearing on the subject's right lower extremity.	Device: SAC+BOOT; Standard axillary crutches (SAC) are ambulatory assistive devices, commonly used for lower extremity injuries or surgeries. A walking boot is a common type of brace/boot that restricts ankle and foot movement.
Experimental: Arm 5. HFC; The fourth intervention condition tested is the Hands Free Crutch worn on the subject's right lower extremity without the walking boot.	Device: HFC; The Hands Free Crutch (HFC) by iWalkFree, Inc. is a novel, ambulatory assistive device that prevents foot and ankle loading while also allowing free use of the arms and hands.; Other Names: Hands Free Crutch; iWalk Free; iWalk 3.0
Experimental: Arm 6. SAC; The fifth and last intervention condition tested is standard axillary crutches with the subject non-weight bearing on the right lower extremity without the walking boot.	Device: SAC; Standard axillary crutches (SAC) are ambulatory assistive devices, commonly used for lower extremity injuries or surgeries.; Other Names: Standard Axillary Crutches; axillary crutches; crutches; underarm crutches

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whole Body Angular Momentum-sagittal Plane	Range of whole-body angular momentum in the sagittal plane during gait using the motion capture system. While angular momentum can be measured in kg*m^2/second it is reported as dimensionless in this study as it has been normalized to body weight (kg), height (m), and walking speed (m/s).	one session (up to 2 hours long), out of 4 total sessions

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whole Body Angular Momentum-transverse and frontal planes	Range of whole-body angular momentum in the transverse and frontal planes during gait using the motion capture system.	Baseline
Segmental Angular Momentum-sagittal, transverse and frontal planes	Range of segmental angular momentum will be compared in the sagittal, transverse and frontal planes during gait using the motion capture system.	Baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Activity-specific Balance Confidence (ABC) Scale	Balance confidence will be assessed using the ABC Scale on 16 activities, using a 0-100% scale (0% = no confidence and 100% = completely confident).	Baseline
Participant Device Comfort Score	A modified device comfort scale using an 11-point rating overall score (0=Most Uncomfortable; 10=Most Comfortable).	Baseline
Numerical Pain Rating Scale	Pain will be assessed using a standard 11-point numerical pain rating scale, in which 0 = no pain and 10 = worst pain imaginable.	over three sessions (an average of 2 hours for each session)
Participant Device Numerical Score	A modified device comfort scale using an 11-point rating scale (0=worst assistive device;10=best assistive device).	over four sessions (an average of 2 hours for each session)
Participant Device Preference	The participant will rank in order (1-4) their preference of assistive device: NONE, BOOT, HFC and SAC.	one session (up to 2 hours long), out of 4 total sessions

Collaborators and Investigators

• Sponsor: University of Iowa
• Collaborators: iWalkFree, Inc.
• Investigators: Principal Investigator: Jason M Wilken, PT, PhD, University of Iowa, Department of Physical Therapy and Rehabilitation Science

Study record dates

Study Major Dates

• Study Start (Actual): October 5, 2021
• Primary Completion (Actual): January 27, 2022
• Study Completion (Actual): January 27, 2022

Study Registration Dates

• First Submitted: July 18, 2021
• First Submitted That Met QC Criteria: July 18, 2021
• First Posted (Actual): July 27, 2021

Study Record Updates

• Last Update Posted (Actual): May 22, 2023
• Last Update Submitted That Met QC Criteria: April 25, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Keywords: Balance; Adult; Biomechanics; Gait analysis; Assistive devices; Hands Free Crutch; Crutches; Walking stability; Walking boot
• Other Study ID Numbers: 202101408

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No