Improved rig for dynamically calibrating skinfold calipers: Comparison between Harpenden and Slim Guide instruments

Abstract

This article describes an improved rig for the dynamic calibration of skinfold calipers. The new unit is 5% lighter and almost 60% smaller than its predecessor (Carlyon et al., 1996, 1998) with a 9.5 mm solid aluminium base and a quick release caliper mount providing stability to both the rig and caliper. Automation of the gap controller with an electric motor standardizes the jaw opening and closing velocity, thereby enabling hands-free operation. Frictional losses in the moving components of the rig have been reduced by replacing the main bush of the swing arm with a bearing, reducing the mass of the swing arm, adding a support wheel to the end of the swing arm, and replacing fishing swivels with a universal joint to allow for changes in the opening screw angle as the caliper's arm moves through its arc. This rig can also be adapted to different types of calipers by changing the position of the load cell, microswitches, and the caliper mount. A universal mounting bracket that can be secured to almost any table supports the rig in a vertical plane when calibrating the load cell. To demonstrate the versatility of the calibration rig, preliminary data are presented for the upscale and downscale jaw pressures of seven Harpenden and seven Slim Guide calipers.

To what extent does sexual dimorphism exist in competitive powerlifters?

“…The equations of colleagues (1987a, 1987b), which were used to estimate the body fat percentages of the lifters, were developed from Harpenden-derived skinfold data, whereas in the present study Slim Guide calipers were used. As the downscale pressure of the Slim Guide may be greater than that of the Harpenden caliper (Hewitt, Withers, Brooks, Woods, & Day, 2002), it is possible that the body fat percentages calculated in the current study were slightly underestimated. While the magnitude of this inter-caliper difference in calculated body fat percentage has not been determined, it is unlikely to be a simple linear relationship, as the magnitude of the inter-caliper difference in jaw pressure changes as a function of a number of factors, including the size of the jaw gap at the time of measurement (Hewitt et al, 2002).…”

Changes in body composition after spasticity treatment with intrathecal baclofen

“…Body composition. Body composition was calculated based on anthropometry with a skinfold calliper (Slim Guide Caliper) (21,22), according to a standardized procedure, including measurements of skinfold thickness over the triceps brachii, biceps brachii, subscapular region and abdominal region laterally, above the pelvis. Data collectors calibrated techniques in using the skinfold calliper before the study start.…”

Skinfold calipers: which instrument to use?

“…The physical, mechanical and functional specifications of the Harpenden®, Lange® and Slim Guide® skinfold calipers discussed in this report were reviewed and described based on original studies (4)(5)(6) and evidence from important complementary experiments (7,(14)(15)(16)(17)(18) . The digital illustrations presented below were made by the author of this report and are unique in their originality and richness of detail.…”