PO-14 · Outcomes and Energy Expenditure

Outcomes and Energy Expenditure. Part of the Prosthetics & Orthotics series of the Reflex PM&R Board Review podcast. Audio corrections: (1) In the audio: Rehabilitation raises the metabolic rate only about 9% above resting per minute. — Correct: The 9% figure is measured against normal walking, not against resting metabolic rate. Level-ground wheelchair propulsion in paraplegia costs roughly 9% more energy than walking; almost any activity raises metabolic rate far more than a tenth above rest. (2) In the audio: patients are eligible for multi-axial feet, polycentric knees, and hydraulic swing control ... At K2, hydraulic swing control uses fluid resistance that increases as velocity increases. — Correct: At K2 the fluid-controlled option in the coverage table is pneumatic swing control. Hydraulic swing control sits on the K3 row, alongside the microprocessor knee and the energy-storing foot. (3) In the audio: Traumatic transtibial adds 10 to 25%. Vascular transtibial adds 20 to 40%. Traumatic transfemoral adds 60 to 70%. Vascular transfemoral adds 65 to 100%. Hip disarticulation adds 82 to 125%. — Correct: Three of those five are wrong. Vascular transtibial is about 40 percent, not 20 to 40: the lower bound is the traumatic figure. Traumatic transfemoral is 55 to 65 percent, since primary values cluster 49 to 65 percent and 60 to 70 could not be verified as a Waters 1976 value. Vascular transfemoral is 100 to 120 percent, not 65 to 100 - off by roughly a factor of two at the lower bound, with the 2021 meta-analysis giving 102 percent. Hip disarticulation is 80 to 125 percent, not 82 to 125, and that range covers hip disarticulation and hemipelvectomy together rather than hip disarticulation alone. Every figure is oxygen cost per unit distance at self-selected speed. (4) In the audio: Hip disarticulation sits precisely between unilateral and bilateral transfemoral at 82-125%. — Correct: At 80 to 125 percent the band overlaps the unilateral vascular transfemoral figure of 100 to 120 percent rather than sitting cleanly above it. The ordering cue only worked because the vascular transfemoral number was too low. The written chapter is correct. Full correction register: https://www.reflexpmr.com/errata. The full companion chapter and a linked board-style Q-bank set for this topic are at https://www.reflexpmr.com/read/PO-14.