The nuchal ligament in a horse supports the weight of the horse's head. This ligament is much more elastic than a typical ligament, stretching from 15% to 45% longer than its resting length as a horse's head moves up and down while it runs. This stretch of the ligament stores energy, making locomotion more efficient Measurements on a segment of ligament show a linear stressversusstrain relationship until the strain approaches 0.80. Smoother] data for the stretch are shown in (gure 1). Figure 1 of 1 Stress ('N/ml} 6.0)(105 4.0>