In the Netherlands, each year 12,000 older cyclists require medical attention due to a single-bicycle accident where no other party is directly involved. Most of these accidents occur at low cycling velocities and 20% occur during (dis)mounting the bicycle. Little is known about the strategies and corresponding kinematics of (dis)mounting. This study aims to classify (dis)mounting strategies of young and older cyclists and assess corresponding kinematics. Thirteen young (18–40 years) and 33 older (65–90 years) cyclists, 13 with and 20 without a bi-cycle fall-history, participated. They were asked to mount the bicycle, cycle normally, stop and wait, continue cycling and dismount the bicycle at a certain point. Bicycle and cyclist motions were recorded with 10 Inertial Measurement Units and 2 video cameras. Kinematic parameters during the (dis)mounting period were assessed. First, a qualitative analysis of the different methods of (dis)mounting and ‘waiting’ was made from the videos. Second, a quantitative assessment of the relationships between age, fall-history, gender and the kinematic parameters during (dis)mounting and waiting were studied. The authors identified 2 mounting, 3 dismounting and 2 waiting categories, which each consisted of 2 or 3 sub-types based on timing to get on or off saddle and swing leg through frame or over saddle. The categories can mainly be distinguished by the first foot that is lifted on or off the pedal. Older cyclists and females prefer other strategies compared to young cyclists and males, respectively. E.g. during mounting, 70% of the young cyclists lift their inside foot, the foot closest to the bicycle, and place it on the pedal, while 80% of the older cyclists lift their outside foot and put it on the pedal and start pushing off with their inside foot from the ground one or more times. Furthermore, bicycle and cyclist kinematics could be related to age, fall-history and gender. Higher thigh angular velocities and accelerations (around mediolateral axis) were found for older cyclists and females compared to young cyclists and males, respectively. These differences, among others, may explain the high injury risk for older cyclists and females in single-bicycle accidents. (Author/publisher)
Abstract