Cyclogram Planarity is Preserved in Upward Slope Walking

In a recent paper [1] Borghese et al., demonstrated that 4D pelvis-thigh-shank-foot cyclograms of human locomotion are surprisingly planar, if the segmental elevation angles rather than the traditional inter-segmental angles are used. In this work, we demonstrate that the planarity of elevation angle cyclograms is preserved even for slope walking, within a 15 degree range

Cyclogram planarity is preserved in upward slope walking

In a recent paper [1] Borghese et al. demonstrated that 4D pelvis-thigh-shank-foot cyclograms of human locomotion are surprisingly planar, if the segmental elevation angles rather than the traditional inter-segmental angles are used. In this work, we demonstrate that the planarity of elevation angle cyclograms is preserved even for slope walking, within a 15 degree range. Methods Three healthy adult volunteers (1 female, 2 male, ages 20-36) participated in this study after giving informed consent. The subjects were asked to walk at freely chosen speeds on three surface inclinations: 0 degrees, 8 degrees, and 15degrees. Each subject performed 20 trials on each slope angle. A variable inclination ramp (366 cm L x 60 cm W) was constructed for this purpose. We used a single camera system from Vision 1 Corp. to record sagittal plane position data at 30 Hz for five reflective markers attached to bony landmarks [1]: anterior superior iliac crest, greater trochanter, lateral femur epicondyle, lateral malleolus, and fifth metatarsophalangeal joint. At each time instant, the elevation angles of the thigh, shank, and foot were extracted from the marker positions and plotted in a 3 dimensional space. Over a complete gait cycle, these points form a curve- the cyclogram. Pelvis elevation angles were also extracted but were ignored here for 3D illustration purposes. However, the results hold when the pelvis elevation angles are included