An evaluation of controlled ankle movement (CAM) boot mechanics during locomotive changes in elevation

Open Access
Sedlock, Martin
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • John Henry Challis, Thesis Supervisor
  • Jinger Gottschall, Honors Advisor
  • CAM boot
  • Ground reaction force
  • Biomechanics
  • Force-sensing insoles
Controlled ankle movement (CAM) boots are a commonly prescribed treatment in response to a variety of musculoskeletal injuries of the lower limb. However, evidence supporting their efficacy at reducing normal reaction forces experienced by the foot is limited and inconclusive. The experimental portion of this thesis sought to remedy the situation by gauging the effectiveness of CAM boots at reducing the normal reaction forces experienced by the plantar surface of the foot during ambulation. Subjects were tasked with completing nine trials composed of three walking tasks: level surface, inclined/declined ramp, and ascending/descending stairs. Each task was completed under three footwear conditions: Sneakers, CAM boot, and Air CAM boot. Subjects were outfitted with force-sensing insoles that measured the normal reaction forces experienced by the plantar surface of the foot and allowed for the calculation of their derivatives. Four variables were subsequently examined: duration of contact, impact peak force, active peak force, and loading rate. It was hypothesized that CAM boot use will exacerbate asymmetry in all four variables between feet as to offload the injured side, as compared to sneakers. It was predicted this will occur in all walking conditions. For a majority of walking tasks, significant differences were sporadic, leading to rejection of the hypothesis and suggesting no practical benefit of CAM boot use. This excluded the task of ascending/descending stairs. In these trials, both versions of CAM boots were consistently successful at decreasing three of four variables. Results indicated that CAM boots are a valid treatment if regular stair use is unavoidable by the patient. Otherwise, the data suggested CAM boots are not effective at reducing reaction forces.