NCT04032041

SCANREP: Reliability of 3D Lower Limb Scanning

• Status: Terminated
• Phase: —
• Study type: Observational
• Enrollment: 30 (actual)
• Sponsor: University of Iowa · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

3D limb scanning systems have recently been implemented for the clinical fitting of prosthetic and orthotic devices due to substantial decreases in costs. However, little data is available regarding the repeatability and validity of systems currently in use. In this study the investigators seek to evaluate the repeatability and validity of multiple lower limb measurements obtained using low-cost 3D limb scanning technology.

Detailed description

Two groups of subjects will be recruited for this study. The first group (Group 1) will consist of healthy able-bodied individuals with no history of lower extremity trauma. The second group (Group 2) will consist of individuals with unilateral, below knee functional deficits that require an AFO (ankle foot orthosis) for daily activities (e.g. fracture, muscle and/or nerve injury, ankle arthritis, or peripheral neurologic disease). The investigators will obtain a brief medical history to identify major medical conditions or prior injuries that could influence limb geometry, and lead to reliance on an AFO for Group 2 participants. A 3D representation of each participant's lower limb geometry will be obtained using a Structure Core scanner (Occipital, Inc.) which uses an infrared structured light projector to construct a 3D image of an object. The scanner is connected to an iPad; to operate the user rotates the iPad camera around the desired object. In seconds, the entire geometry is digitally reconstructed. Measurements will be evaluated using digital imaging analysis software (Standard Cyborg, Inc.). The investigators will evaluate concurrent validity by directly comparing software-based measurements from limb scans, with direct measurements on the same individual collected using digital calipers. The investigators will determine repeatability of each technique by conducting three identical limb scans and actual physical measurements at two time points on the same day in each individual, and then comparing the results between time points. The interior of the AFO worn by participants in Group 2 will also be scanned to obtain its geometry for comparison with measurements obtained from each individual's limb. Validity and repeatability will be assessed using measurements at multiple locations on the lower leg. Limb measurements will include 1) width of the metatarsal heads, 2) width of the calcaneus, 3) foot length, 4) foot height, 5) arch height, 6) medial-lateral width between ankle malleoli, 7) minimum circumference above the ankle malleoli, 8) maximum calf circumference , 9) medial-lateral width of the knee condyles 10) anterior-posterior width at mid patellar tendon, 11) distance from bottom of foot to tibial tubercle. Concurrent validity will be determined using the intra-class correlation coefficient and absolute error (root mean square error) for comparisons between measurements from limb scanning and the calipers. Reliability will be determined using the intra-class correlation coefficient and the minimal detectable change value for comparisons over time.

Conditions

• Foot Injuries and Disorders

Interventions

Type	Name	Description
DEVICE	Structure Sensor	A 3D representation of each participant's lower limb geometry will be obtained using a Structure Core scanner (Occipital, Inc.) which uses an infrared structured light projector to construct a 3D image of an object. The scanner is connected to an iPad; to operate the user rotates the iPad camera around the desired object. In seconds, the entire geometry is digitally reconstructed.
DEVICE	Caliper	Caliper: An OriginCal IP54 digital caliper (Anytime Inc, Granada Hills, CA) was used to take three consecutive physical measurements in millimeters at each identified measurement location. For measurements outside of the caliper's scope a tape measure was used in place of the caliper. Physical measuring devices were reset to zero between each measure.

Timeline

• Start date: 2019-09-27
• Primary completion: 2021-07-31
• Completion: 2022-07-05
• First posted: 2019-07-25
• Last updated: 2025-01-10
• Results posted: 2025-01-10

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study