Static balance control and lower limb strength in blind and sighted women

Abstract

The aim of the present study was to examine isokinetic and isometric strength of the knee and ankle muscles and to compare center of pressure (CoP) sway between blind and sighted women. A total of 20 women volunteered to participate in this study. Ten severe blind women (age 33.5 +/- 7.9 years; height 163 +/- 5 cm; mass 64.5 +/- 12.2 kg) and 10 women with normal vision (age 33.5 +/- 8.3 years; height 164 +/- 6 cm; mass 61.9 +/- 14.5 kg) performed 3 different tasks of increasing difficulty: Normal Quiet Stance (1 min), Tandem Stance (20 s), and One-Leg Stance (10 s). Participants stood barefoot on two adjacent force platforms and the CoP variations [peak-to-peak amplitude (CoPmax) and SD of the CoP displacement (CoPsd)] were analyzed. Sighted participants performed the tests in eyes open and eyes closed conditions. Torque/angular velocity and torque/angular position relationships were also established using a Cybex dynamometer for knee extensors and flexors as well as for ankle plantar and dorsiflexors. The main finding of this study was that the ability to control balance in both anterior/posterior and medio/lateral directions was inferior in blind than in sighted women. However, when sighted participants performed the tests blindfolded, their CoP sway increased significantly in both directions. There were no differences in most isometric and concentric strength measurements of the lower limb muscles between the blind and sighted individuals. Our results demonstrate that vision is a more prominent indicator of performance during the postural tasks compared to strength of the lower limbs. Despite similar level of strength, blind individuals performed significantly worse in all balance tests compared to sighted individuals.

Michelangelo, ocular bulb, retina and the Creator

“…Besides these anatomical similarities, we can say that both the foot sole somatosensation as visual sensory feedback networks plays a critical role among the active feedback loops that contribute to the control of standing and walking 3,4 .…”

Standing Balance Stability and the Effects of Light Touch in Adults With Profound Loss of Vision—An Exploratory Study

“…There is contradictory evidence in the literature regarding the quiet standing balance stability of severely sight-impaired or blind individuals compared to normally sighted counterparts. Some show that those with severely restricted or no vision have worse balance than normally-sighted subjects, 26,42,45 whereas other have found no significant differences between sighted and nonsighted subjects during quiet standing in either tandem 33 or normal bipedal 24,27 stance, and that differences between seeing and nonseeing subjects only becomes apparent when another sensory system (somatosensory or vestibular) is perturbed. There also may be an element of self-selection bias in this study; patients who volunteered to participate in the project may have had better balance than those who declined, as the latter group may not have had the confidence to participate in the study.…”

Effect Of Level Of Coordination Abilities On Motor Learning Progress In Slacklining

“…It is an active and dynamic process, that is characterised by motoric coordination that supports the spine during all the motions (deep spinestabilising system). Postural stability belongs to those skills, that are influenced by visual control, the vestibular apparatus, and by proprioreception at the same time (Giagazoglou et al, 2009). The ability to maintain and control the balance is the basis for the design and construction of more complex motor skills in the context of sport performance (Altavilla, Tafuri and Raiola, 2014).…”