Analysis of Neuromuscular Control in Young and Older Individuals During Lateral Stepping

Abstract

Older adults can develop neuromuscular deficiencies. We tested the hypothesis that these deficiencies could be reflected in altered neuromuscular control during normal daily tasks. Hence, we compared the ability to modulate ground reaction force (GRF) during lateral stepping (LS) from different step heights between younger and older adults. Kinetic data was obtained from younger (23-33yrs, n=5) and older (57-65yrs, n=5) male and female subjects. They stood on top of two 4-inch/8-inch high platforms. Each platform was placed on separate force plates. The subjects were instructed to step down laterally using their non-dominant leg and then step up to the original position. GRF and joint-angle kinematics of both limbs were recorded for the two-step heights. The time (% total) to achieve maximum amount of force (as % body weight) exerted was calculated using data from the average of three LS trials per subject. It was significantly different between males (32.75±1.57) and females (35.75±1.28) (p=0.012) or between young (33.479±1.43) and old (35.021±1.43) (p=0.018) using a three way repeated measures ANOVA comparing step height (4inch, 8inch), gender (male, female), and age (young, old.) According to the data, neuromuscular control of the LS task is affected by age and gender.

Anatomical and biomechanical factors associated with plantar fasciitis in Thai male conscripts

“…Regarding the biomechanical perspective, individuals with PF had poorer quality of movement from the lateral step down test, reflecting the poorer muscular control from Gluteus maximus, Gluteus medius, Biceps femoris, Vastus medialis, Tibialis anterior, and Gastrosoleus during this task (133). Although the present study did not assess the muscle activity during gait, it was assumed that there were differences of muscle activation between the PF and the control groups.…”

“…Although the present study did not assess the muscle activity during gait, it was assumed that there were differences of muscle activation between the PF and the control groups. The PF group might reduce activation from the hip and knee extensors to stabilize the trunk and limb against the rapid transfer of body weight (133). With poorer hip control in the PF group, excessive activity might be required from extrinsic and intrinsic muscles of the foot to reinforce the medial arch especially during the windlass mechanism, leading to more tension on the plantar fascia (144).…”

“…Lower extremity movement patterns could be categorized into three levels, consisting of good (0-1 point), moderate (2-3 points) and poor (4-6 points) quality of movement(32). The poorer quality of movement from LSD test reflects the poorer muscular control from Gluteus maximus, Gluteus medius, Biceps femoris, Vastus medialis, Tibialis anterior, and Gastrosoleus during this task(133).…”

“…Consequently, it was difficult for persons to naturally transfer body weight from the rearfoot to the medial forefoot during the knee and hip extension(139).Moreover, the PF group had poorer quality of movement. It was thus assumed that they had less activation from the hip and knee extensors to stabilize the trunk and limb against the rapid transfer of body weight(133). Since the femoral anteversion angle and tibial torsion angle of the current sample fell within normal range (between 8° and 15° for femoral anteversion; and between 20° and 40° for tibial torsion), any changes in multi-segment foot and lower extremity kinematics during this phase might be due to the poor muscular control from trunk and hip other than the anatomical structures.…”