Transfemoral Osseointegrated Prosthesis Limb-Load Symmetry Training

Intervention feasibility is measured by retention rate, the percentage of people that complete the study. A score can range between 0 and 100 percent with 100 percent meaning all randomized participants completed the study.

Acceptability of an intervention is the perception among stakeholders (e.g., patients and clinicians) that the intervention is agreeable or satisfactory. To measure participant acceptability, the investigators will use the Acceptability of Intervention Measure, a 30 four-item survey of stakeholder perception of intervention acceptability that asks participants to provide their approval as well as intervention appeal, likability, and agreeability. The scores range from 1 (completely disagree) to 5 (completely agree). The investigators expect the Acceptability of Intervention Measure score (average of the four items on a 1-5 scale) for the EXP group to be at least 4 (agree).

This will be evaluated based on whether EXP group interventionists deliver the intervention as planned and quantified in three ways: adherence, delivery quality, and patient engagement. The investigators will use the overall results of these three fidelity components to create a total score. Fidelity scores are reported as a percentage from 0 to 100 with 100 representing full fidelity. The investigators will consider >85% fidelity (average across all three components) to intervention delivery as a positive result.

Free-living physical activity will be objectively monitored over a 10-day period using an activPAL micro accelerometer-based sensor (PAL Technologies, Glasgow, UK). Interlimb cumulative loading will be measured as a product of daily step count and ground reaction force impulse. Cumulative loading = (Daily Steps/2)*ground reaction force impulse.

Bilateral hip movement patterns (joint angles), muscle forces, and joint reaction forces will be calculated during functional tasks of increasing biomechanical demand (walking, sitting, stepping, turning) using a combination of motion capture and subject-specific musculoskeletal models. Whole-body motion capture will be collected from 70 reflective markers (Fs=120 Hz) (Vicon, Centennial, CO) with ground reaction forces simultaneously collected from six embedded force platforms (Fs=2,160 Hz) (Bertec, Columbus, OH). A subject-specific musculoskeletal model will be created using OpenSim software.

Self reported questionnaire measuring disability in adults age 18 years and older. Final scores range from 0 (no disability) to 100 (full disability).

Self reported measure of balance confidence. Final scores range from 0% (no confidence in balance) to 100% (complete confidence in balance).

A 12 item self report questionnaire measuring participants mobility when using a prosthesis. Final scores range from 12 to 60 points with higher scores indicating greater mobility.

Self reported questionnaire measuring the ability of the participant to do 3 self identified activities. Scores of each of the 3 activities range from 0 (unable to perform) to 10 (able to perform without difficulty). Total scores range from 0 to 30 points, with higher scores indicating higher function.

Test to quantify walking ability as it is associated with health outcomes, fall risk, and mobility levels and is also a frequent indicator of intervention effectiveness. The time it takes each participant to walk 5-meters (after 3-meter acceleration zone, followed by 3-meter deceleration zone). The self selected gait speed will be averaged over three trials.

Test to assess lower-extremity strength and endurance. The number of times the participant can rise from sitting in 30 seconds.

A specific test to measure physical function and balance. The time it takes a participant to don their prosthesis, rise from sitting, walk 10 feet and turn, walk back to the chair and return to seated position.