Pedal forces, joint forces, and sagittal plane moments of the knee in non-injured and injured subjects

• Main Author: Chinworth, Susan A
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.1997
• Subjects: Injuries; Kinesiology; Knee; Mechanics; Motor ability; Physical therapy; Rehabilitation; Sports medicine; Therapy
• ISBN: 0591548062; 9780591548068

The purpose of this study was to measure the pedal forces, calculate the joint reaction forces and moments about the right knee in two dimensions at two resistances, and compare the results within and between both injured and non-injured subjects. A secondary purpose of the study was to construct a relatively inexpensive, yet accurate, force pedal to measure forces in two dimensions. The problem was to determine if significant differences existed in shear and normal pedal forces, shear and normal knee joint forces, and sagittal plane knee joint moments between and within injured and non-injured groups while riding a stationary bicycle at two resistances. Subjects were 9 non-injured and 8 injured subjects of either gender and 18 years of age or older. The subjects rode the bike at 60 rpm at 1 kg and 2 kg resistances. The kinematic data were matched in time with the kinetic recordings of force to calculate shear and normal knee joint forces and sagittal plane knee moments. Problems with the pedal included decoupling of forces, quantification of normal forces, and noise. There were some differences observed visually with the time history curves as well as variations in magnitudes between the injured subjects and non-injured subjects in force production. However, most of the differences seen in this study were within the groups, not between the groups. The forces produced were less than normalized body weight and were generally below 1.0 normalized leg weight (LW). The higher resistance produced greater mean peak values than the lower resistance. Two-way repeated measures ANOVAs with a Bonferroni adjustment determined that there were no significant differences between and within the two groups for each variable. The study supports the clinical evidence that the bike can be safely used for most patients with post-op knee injuries.