1C70 Feasibility Study

Prospective, Feasibility Study to Evaluate Performance, Patient Benefits, and Acceptance of a New 1C70 Energy Storage and Return Prosthetic Foot

The objective of this study is to characterize the extent of 1C70 meeting the amputees needs in comparison with their everyday and a comparator foot, in regards of daily activities, mobility and balance, as well as quality of life and pain.

Study Overview

• Status: Completed
• Conditions: Amputation
• Intervention / Treatment: Device: 1C70; Device: Pro-Flex XC

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Göttingen, Germany
    • Zentrum für Healthcare Technology der Privaten Hochschule Göttingen (ZHT PFH)
  • Hannover, Germany
    • John+Bamberg
  • Heidelberg, Germany
    • Pohlig Heidelberg
  • Münster, Germany
    • UKM ProTec
  • Nürnberg, Germany
    • Pohlig Nürnberg
  • Traunstein, Germany
    • Pohlig Traunstein

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Person is at least 18 years old.
• Person is a unilateral transtibial amputee with stabilized residual limb.
• Person is a K3 ambulator based on Medicare Functional Classification Level (MFCL) .
• Person has at least 6 months experience in walking with a prosthesis.
• Person is using an energy storage and return (ESR) foot as their primary everyday foot
• Person has a foot size between 22 and 30.
• Person weights with a prosthesis between 50 and 125 kg (foot size 26 - 30), or between 45 and 100 kg (foot size 22 - 25).
• Person wears a prosthesis daily and ≥ 8 hours/day.
• Person is able to walk at least 500 m without having to make a break.
• Person is willing and able to independently provide informed consent.
• Person is willing to comply with study procedures.

Exclusion Criteria:

• Person is pregnant.
• Person is using a hydraulic foot as their primary everyday foot.
• Person is using a sport foot (e.g., Fillauer AllPro, Ottobock Challenger, Össur Flex-Foot Cheetah) as their primary everyday foot.
• Person is using an ESR foot with an integrated vacuum pump (e.g., Ottobock 1C62 Triton Harmony).
• Person has conditions that would prevent participation and pose increased risk (e.g., unstable cardiovascular conditions that preclude physical activity such as walking).
• Person falls ≥ once a week due to the reasons that are not related to prosthesis (e.g., problems with vestibular system).
• Person is not available for study visits during planned study duration.
• Person is participating in another study or intends to participate in another study during this study´s duration.
• Person cannot personally provide their consent.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1C70 to Pro-Flex XC; Transtibial amputees randomized to start with 1C70 and cross over to Pro-Flex XC	Device: 1C70; Investigational energy storage and return prosthetic foot with using novel elastic elements.; Device: Pro-Flex XC; Commercially available carbon-fiber energy storage and return foot used as comparative foot for transtibial amputee subjects.
Experimental: Pro-Flex XC to 1C70; Transtibial amputees randomized to start with Pro-Flex XC and cross over to 1C70	Device: 1C70; Investigational energy storage and return prosthetic foot with using novel elastic elements.; Device: Pro-Flex XC; Commercially available carbon-fiber energy storage and return foot used as comparative foot for transtibial amputee subjects.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Extent of meeting amputees prosthetic foot needs: 1C70 vs everyday foot	The extent of meeting amputees prosthetic foot needs by 1C70 as measured by a single question with a 0 to 10 scale compared to the same score for everyday foot. Higher score correspond with higher extent of meeting amputees prosthetic foot needs.	2 months after fitting with the last study feet
Extent of meeting amputees prosthetic foot needs: 1C70 vs comparator foot	The extent of meeting amputees prosthetic foot needs by 1C70 as measured by a single question with a 0 to 10 scale compared to the same score for comparator foot. Higher score correspond with higher extent of meeting amputees prosthetic foot needs.	2 months after fitting with the last study feet
Change in patient-perceived mobility (PLUS-M) compared to baseline	The change from baseline perception of mobility as measured by the Prosthetic Limb Users Survey of Mobility (PLUS-M) 12-item short form. The PLUS-M questionnaire provides a T-score that ranges from 21.8 to 71.4. Higher PLUS-M scores correspond with greater mobility.	Baseline measurement vs 2 months after fitting with 1C70
Change in patient-perceived mobility (PLUS-M) compared to the comparator foot	The change from baseline perception of mobility as measured by the Prosthetic Limb Users Survey of Mobility (PLUS-M) 12-item short form. The PLUS-M questionnaire provides a T-score that ranges from 21.8 to 71.4. Higher PLUS-M scores correspond with greater mobility.	2 months after fitting with each of the study feet
Highest pain reported: 1C70 vs everyday foot	The level of pain as a highest pain during preceding 7 days reported on a 0 ("No pain at all") to 10 ("the most intense pain imaginable") scale for the following origins: residual limb, sound limb, back, shoulder & neck area, phantom limb pain, while wearing the 1C70 foot compared to the everyday foot.	Baseline measurement vs 2 months after fitting with 1C70
Highest pain reported: 1C70 vs comparator foot	The level of pain as a highest pain during preceding 7 days reported on a 0 ("No pain at all") to 10 ("the most intense pain imaginable") scale for the following origins: residual limb, sound limb, back, shoulder & neck area, phantom limb pain, while wearing the 1C70 foot compared to the coparator foot.	2 months after fitting with each of the study feet

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in patient perceived balance confidence (ABC) compared to baseline: 1C70 vs everyday foot	Perception of balance confidence as measured by the Activities-specific Balance Confidence (ABC) Scale. The questionnaire provides a score that ranges from 0 to 100%. Higher scores indicate greater balance confidence.	Baseline measurement vs 2 months after fitting with 1C70
Change in patient perceived balance confidence (ABC) compared to baseline: 1C70 vs comparator foot	Perception of balance confidence as measured by the Activities-specific Balance Confidence (ABC) Scale. The questionnaire provides a score that ranges from 0 to 100%. Higher scores indicate greater balance confidence.	2 months after fitting with each of the study feet
Quality of life as measured by the EQ-5D-5L: 1C70 vs everyday foot	Measure of health status composed of 5 dimensions: mobility, ability to self-care, ability to undertake usual activities, pain and discomfort, anxiety and depression. Each dimension is rated on a 5-point scale indicating the level of perceived problems for each dimension (level 1 indicating no problems and level 5 indicating extreme problems). Each health state can potentially be assigned a summary index score based on societal preference weights for the health state. These weights, sometimes referred to as 'utilities', are often used to compute QALYs for use in health economic analyses. Health state index scores generally range from less than 0 (where 0 is the value of a health state equivalent to dead; negative values representing values as worse than dead) to 1 (the value of full health), with higher scores indicating higher health utility.	Baseline measurement vs 2 months after fitting with 1C70
Quality of life as measured by the EQ-5D-5L: 1C70 vs comparator foot	Measure of health status composed of 5 dimensions: mobility, ability to self-care, ability to undertake usual activities, pain and discomfort, anxiety and depression. Each dimension is rated on a 5-point scale indicating the level of perceived problems for each dimension (level 1 indicating no problems and level 5 indicating extreme problems). Each health state can potentially be assigned a summary index score based on societal preference weights for the health state. These weights, sometimes referred to as 'utilities', are often used to compute QALYs for use in health economic analyses. Health state index scores generally range from less than 0 (where 0 is the value of a health state equivalent to dead; negative values representing values as worse than dead) to 1 (the value of full health), with higher scores indicating higher health utility.	2 months after fitting with each of the study feet
Pain interference: 1C70 vs everyday foot	Perception of pain interference on the usual activities as measured by a single question with a 0 ("Does not interfere") to 10 ("Completely interferes") scale.	Baseline measurement vs 2 months after fitting with 1C70
Pain interference: 1C70 vs comparator foot	Perception of pain interference on the usual activities as measured by a single question with a 0 ("Does not interfere") to 10 ("Completely interferes") scale.	2 months after fitting with each of the study feet
Foot preference overall and for use in several specific activities	Foot preference overall and for use in several specific activities as measured by a questionnaire from the publication of Morgan et al. (Morgan et al. 2018)	2 months after fitting with the last study feet

Collaborators and Investigators

• Sponsor: Otto Bock Healthcare Products GmbH
• Collaborators: Ottobock SE & Co. KGaA

Publications and helpful links

General Publications

• Morgan SJ, McDonald CL, Halsne EG, Cheever SM, Salem R, Kramer PA, Hafner BJ. Laboratory- and community-based health outcomes in people with transtibial amputation using crossover and energy-storing prosthetic feet: A randomized crossover trial. PLoS One. 2018 Feb 7;13(2):e0189652. doi: 10.1371/journal.pone.0189652. eCollection 2018.

Study record dates

Study Major Dates

• Study Start (Actual): November 24, 2022
• Primary Completion (Actual): May 30, 2023
• Study Completion (Actual): June 28, 2023

Study Registration Dates

• First Submitted: November 16, 2022
• First Submitted That Met QC Criteria: November 16, 2022
• First Posted (Actual): November 28, 2022

Study Record Updates

• Last Update Posted (Actual): June 10, 2025
• Last Update Submitted That Met QC Criteria: June 5, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: amputation; transtibial; prosthetic foot
• Other Study ID Numbers: D000002112; CIV-22-08-040306 (Other Identifier: European database on medical devices (EUDAMED))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is no plan to share IPD.

Drug and device information, study documents

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