Equipment and apparatus

An Improved Electrogoniometer for Recording Knee-Joint Angles

V. B. Kanevsky, State Central Institute of Physical Culture (GTsOLIFK), Moscow

English summary of Tyazhelaya Atletika. Ezhegodnik 1983 (Moscow: Fizkultura i Sport, 1983), pp. 65–66: the text is paraphrased, not translated; figures are the original images.

Purpose

Electrogoniometers with PTP-type wire-wound potentiometers record joint angles continuously for N-327 chart recorders or the N-117 oscillograph; they are simple, fit any joint and serve both research and immediate technique feedback.

Problem

Ankle, hip and elbow pose no difficulty. At the knee, from lift-off to knee height, the forearm strikes the square-cornered metal potentiometer housing, especially in the narrow-grip clean: it obstructs the pull, can injure the arm, and athletes alter their technique to avoid it.

Modification

Replace the housing cover with a lathe-turned mushroom-cap cover, sized to the housing.
Material: any light one, preferably dielectric (ebonite, acrylic glass, plastic).

Cross-section of the electrogoniometer with a dome-shaped cover over the potentiometer housing and two clamping strips — Design of the electrogoniometer: 1 — potentiometer housing; 2 — cover; 3 — axle; 4 — fixed clamping strip; 5 — movable clamping strip; 6 — cover-fixing screw.

Result

Athletes lift unhindered, and knee-angle records become far more reliable for research and for immediate feedback to athletes and coaches.