The relationship between gait mechanics and running ground reaction forces is widely regarded as complex. This viewpoint has evolved primarily via efforts to explain the rising edge of vertical force-time waveforms observed during slow human running. Existing theoretical models do provide good rising-edge fits, but require more than a dozen input variables to sum the force contributions of four...

The aim of this study was to investigate the effect that changing step height had on ground reaction force. Using a randomised crossover design, 12 volunteers with no previous experience of step aerobics were recruited to perform at three different step heights: 6, 8 and 10 inches. Subjects performed a basic step at a cadence of 120 beats/min and performed three one minute trials during which g...

The prosthetic sockets of 14 independent persons with unilateral trans-tibial (BK) amputation were mounted on an adjustable alignment pylon. Vertical ground reaction forces were recorded in neutral prosthetic alignment and in 10 degrees of prosthetic socket varus, valgus, flexion, and extension. Stance phase time, peak vertical ground reaction force, and impulse were all found to be increased o...

A non-contact anterior cruciate ligament (ACL) injury is both a serious and very common problem in volleyball. The aim of the study was to determine the association between stick, step-back, and run-back landings after a block and select risk factors of ACL injuries for female professional volleyball players. The research sample involved fourteen female professional volleyball players. Two forc...

Objective—To examine the eVects of instructions related to joint kinematics, auditory stimuli, and imagery on lowering the vertical ground reaction forces associated with landing from a jump. Study Design—Randomised controlled trial. Setting—A laboratory in an educational institution. Subjects—Eighty asymptomatic subjects (27 men) with a mean age of 24 years. Intervention—Subjects were randomly...

OBJECTIVE To examine the effects of instructions related to joint kinematics, auditory stimuli, and imagery on lowering the vertical ground reaction forces associated with landing from a jump. STUDY DESIGN Randomised controlled trial. SETTING A laboratory in an educational institution. SUBJECTS Eighty asymptomatic subjects (27 men) with a mean age of 24 years. INTERVENTION Subjects were...

Background. Human feet have important roles in supporting, moving and balancing the body. The feet must not only support the weight of the body but must also have the elasticity to absorb the burden associated with supporting excessive body weight. Objectives. The purpose of this study was to compare the difference of foot pressure, ground reaction force, and balance ability according to chang...

Impact forces and shock deceleration during jumping and running have been associated with various knee injury etiologies. This study investigates the influence of jump height and knee contact angle on peak ground reaction force and segment axial accelerations. Ground reaction force, segment axial acceleration, and knee angles were measured for 6 male subjects during vertical jumping. A simple s...

OBJECTIVE To examine the frequency domain characteristics of the ground reaction forces of young and elderly females during free walking. DESIGN Independent t-tests were used to examine the frequency content of all three components of the ground reaction force. BACKGROUND Frequency domain analysis has the potential to assist in identifying changes in gait that may be masked in the time doma...

The purpose of this investigation was to develop normative ground reaction force data for able-bodied (AB) and trans-tibial amputee (TTA) children during running. Two hundred AB (mean age 9.4 years, range 7-12) and 21 TTA (mean age 11.1 years, range 5-17) children ran (2.2 m/s +/- 10%) over a force platform. Ground reaction force data were normalized, averaged within groups and plotted to produ...