Abstract: A device providing a sensory indication that the hands of a user executing a sit-up have moved a selected distance desired for proper execution of the sit-up, including an adjustable width base plate having substantially parallel channels disposed on opposite sides thereof, and slide plates disposed in each channel and having an upper surface engageable with the hands of a user, the slide plates being movable the selected distance in the channels between the channel ends. Users of the device consistently, uniformly perform a sit-up which minimizes unnecessary strain on the person's back by first positioning themselves in a starting position on their backs and on the device with their arms extended lengthwise of and parallel to their body. Their hands are then positioned on top of the slide plate positioned with its back end abutting the trailing end of the channel.

Abstract: A hand held instrument for determining the degree of angular deviation of a line between selected points on a subject from a gravity-dependent reference, including a transparent base through which the selected points may be viewed and a gravity-dependent indicator mounted on the base for free rotation under the influence of gravity. The base includes indicia complementary with the gravity-dependent indicator to provide an indication of the degree of deviation between the gravity-dependent indicator and the line between selected points on the subject when the instrument is held in a substantially upright position.

Abstract: A device for hydrostatic weighing of humans in existing swimming pools having a cradle for supporting a human body under water, a scale suspending the cradle for measuring the percent body fat of a human, a beam suspending the scale over the pool and a support frame for suspending the beam over the water. The frame includes a hollow base leg, a hollow upright post at the end of the base leg, and an upright post at the poolside end of the base leg so that the beam may be adequately supported. The weight of the human in the cradle is counterbalanced by filling the hollow base leg and hollow upright post with water by means of a hose and valve assembly located at the front of the base leg.

Abstract: An instrument for measuring the girth of compressible objects comprising a graduated tape and a one-piece tension reading member. The tension reading member is substantially planar and comprises first and second sections interconnected by a reduced cross-sectional bendable hinge portion which permits relative movement of the first and second sections in the plane of the member. The first section is secured with the tape and controlled by grasping and drawing the tape with one hand. The second section is drawn in an opposite direction by the other hand, thereby tensioning the tape and deforming the hinge portion. The tension applied to the tape is indicated by the relative positions of the first and second portions and preferably by aligned scales on each. The first portion has an arm which is extensible within a corresponding cutout in the second section. The arm has an expanded end which engages a pair of stops protruding into the cutout to revent overstressing of the hinge portion.