ABSTRACT
@#The ground reaction force (GRF) is the equal opposing load transfer from the body to the ground, also called vertical load transfer. The GRF would produce stress waves transmitted toward the lower extremities during the heel strike of a gait cycle. Too much force imposed on the lower extremities for an extended period will cause harmful effects such as injuries or alterations in gait. This article presents a review of the literature on GRF analysis among adults with lower limb problems where comparisons between healthy and unhealthy subjects were analyzed, focusing on the compensation in each lower limb. A literature search of published articles in Science Direct and PubMed databases from August 2015 to March 2021 was analyzed. The keywords used for the search were (plantar force OR vertical load transfer OR ground reaction force) AND (lower limb OR lower extremities OR leg OR foot) AND (impairment OR problem OR injury). The literature search identified 22 relevant studies which were screened independently by two reviewers. Lower limb problems such as unilateral transfemoral amputation, unilateral transtibial amputation, patellofemoral pain, anterior cruciate ligament injury, knee arthroplasty, knee osteoarthritis, diabetic foot, total hip replacement, pronated foot proved to alter the GRF significantly. Patients used to shift their weight on the opposite leg as compensation, which acts as a pain-free mechanism. This paper has provided sufficient understanding regarding GRF among adults with lower limb problems. The knowledge concerning compensation may help physical therapists implement the appropriate intervention for patients with lower limb problems.
ABSTRACT
Objective The aim of the study is to investigate whether the progressive incremental exercise can induce the change in bone maximum force.Methods One hundred and seventy healthy SD rats,aged 3 months,were used as samples after adaptive exercise for one week,and then they were divided to a basic control group(C_0),8 control groups and 8 exercise groups according to the training duration(2W,4W,6W,8W,9W,11W,13W and 15W).Based on Bedford and our pre-study.the longest training duration of the rats was 15 weeks.The maximum force(F) of femoral bone and the 2nd lumbar vertebrae(L_2)were tested by three-point bending test and compressive test separately.Results It was shown that there was no pronounced difference in F of femoral bone between con trol groups and exercise groups.But significant differences in F of L_2 were found between the control groups and exercise groups(P<0.001).Conclusions Changes in different degree were found in the F of femoral bone and L_2 during the process of growth.The differential effects of incremental exercise on F were caused by the difference in training intensities and in the bone types.