Assessment of the Effects of Saddle Position on Cyclistsʼ Pedaling Technique

Abstract

Several studies have investigated changes in pedaling technique when the cyclist to bicycle interface is altered. However, none have investigated the effects of changes in fore and aft saddle position. PURPOSE: To analyze the effects of altering body position with the following variables: (1) economy of movement (EC); (2) pedal forces; (3) index of effectiveness (IE); (4) alteration in the trunk, hip, knee, and ankle joint angles; and (5) electrical activation of the muscles selected. METHODS: Three (n = 3) elite cyclists participated in this study. The protocol consisted of the evaluation of four different saddle position (fore, aft, up, and down) compared to the reference position while cycling at the cyclists preferred cadence. All measurements were obtained at the same VO2 for each subject. The subjects' bicycles were assembled in a magnetic cycle simulator, and the dynamometric pedal was fixed on the bicycles to acquire the normal and tangential components of the force applied on the pedal. Electrical activation of six lower limb muscles were recorded: gluteus maximus, rectus femoris, biceps femoris, vastus lateralis, gastrocnemius medialis, and tibialis anterior. The resultant and effective forces were calculated from normal and tangential forces to obtain the IE. Analysis was calculated from 10 pedal cycles. The EC was calculated from VO2 and from the power output. RESULTS: Saddle position altered the direction and magnitude of the forces and consequently the IE. Subjects demonstrated a better IE and a better EC in the reference position. Kinematic data showed little variation in the joint angles due to changes in the saddle position. Electrical activation changed both in the activation period and in the magnitude of the root mean square in all the saddle positions evaluated. CONCLUSION: EC and IE are optimal in the reference saddle position which may indicate an adaptation of skeletal muscle to years of training in this position.