Asymmetric balance control between legs for quiet but not for perturbed stance

Abstract

Interlateral performance asymmetry in upright balance control was evaluated in this investigation by comparing unipedal stance on the right versus the left leg. Participants were healthy young adults, hand-foot congruent preference for the right body side. Balance performance was evaluated in unperturbed quiet stance and in the recovery of balance stability following a mechanical perturbation induced by unexpected load release. Evaluation was made under availability of full sensory information, and under deprivation of vision combined with distortion of sensory inputs from the feet soles. Results from perturbed posture revealed that muscular response latency and postural sway were symmetric between the legs. Unipedal stance was more stable when the body was supported on the right as compared with the left leg. No interaction was found between leg and sensory condition. Our findings are interpreted as resulting from specialization of the sensorimotor system controlling the right leg for continuous low-magnitude postural adjustments, while corrections to large-scale stance sway are symmetrically controlled between body sides.

The development of a novel method of recording centre of gravity location in bipedal stance in healthy adults

“…Clinically this suggests that, for healthy adults, there is an anterior shift of COG in SLS tests. This result agrees with the significant findings in the study by Teranishi with the right foot (Clifford & Holder-Powell, 2010) and greater stability in right SLS compared with the left (Vieira et al, 2014). This may have implications for gait performance particularly in patients who have had a stroke.…”

“…In RSLS the proportions were very similar for each of the three age groups (92-97%). This does seem to agree with Vieira et al (2014) who found, in young adults, greater stability for stance on the dominant lower limb. If, as Nichols et al (1995) have suggested, an anterior shift occurs to position the COG closer to the centre of the BOS to increase the distance of the COG from the BOS boundaries and enhance stability, the greater proportions of anterior location in the LSLS for the young and middle groups may indicate less confidence in control for stance on the non-dominant foot and therefore a need to be closer to the centre of the BOS.…”

“…However, other studies have observed some differences between dominant (preferred limb used for skilled activities) SLS and non-dominant (preferred stance limb) SLS in groups of young adults (Clifford & Holder-Powell, 2010;Vieira, Coelho, & Teixeira, 2014). These researchers found an increased range of COP sway in LSLS (Clifford & Holder-Powell, 2010) and greater stability in RSLS (Vieira et al, 2014) respectively. For the participants in both of these studies the left lower limb was the non-dominant limb and the right lower limb was the dominant limb.…”

“…In a study of men across three age groups (young, middle and older) (Murray et al, 1975) also found no difference in the COG location between the dominant and non-dominant limbs for single limb stance for any group. However, other studies have observed some differences between dominant (preferred limb used for skilled activities) SLS and non-dominant (preferred stance limb) SLS in groups of young adults (Clifford & Holder-Powell, 2010;Vieira, Coelho, & Teixeira, 2014). These researchers found an increased range of COP sway in LSLS (Clifford & Holder-Powell, 2010) and greater stability in RSLS (Vieira et al, 2014) respectively.…”

“…However, there was only a trend to significance when the younger age group (30-49 years) was compared to the older age group (65-80 years). Some studies have identified differences between the dominant and nondominant limbs for SLS in younger groups (Clifford & Holder-Powell, 2010;Vieira et al, 2014) while in another study of adults in three age groups no difference was found (Murray et al, 1975). …”