Foot-Length Asymmetry, Sex, and Handedness

On the Relation between Footedness and Handedness

The relation between handedness and footedness was examined for 32 righthanders and 32 lefthanders. On a speed-tapping task, righthanders showed a significant right-hand and right-foot advantage. Lefthanders showed a significant left-hand advantage and a significant right-foot advantage. This appears to support previous work. However, while the right-foot advantage of righthanders proves robust over different replications, the right-foot advantage of lefthanders does not show such robustness. Results show tacit agreement with Annett's 1972 model which suggests an inherent right-shift bias for righthanders and no inherent directional bias for lefthanders.

Anatomical and behavioural asymmetries in right and left handers from India

A biometric study of the right and left limb size and functional-behavioural measures, such as, strength of the hand and the foot, foot-eye-ear preferences, asymmetries in visual acuity and audiometry, asymmetries in taste and smell perceptions was made in a sample of Indian students to find out the interrelationships between the above parameters. Healthy adult male (n = 42), females (n = 45) right handers, and, male (n = 21), female (n = 20) left handers were studied. In each, 8 measurements of each of the limbs were taken, and the strength of the hands and feet determined. Hand and foot preferences were determined through 11 and 9 tasks respectively. Dominance in the eye, ear, taste and smell were ascertained by various tests. Right or left handedness and right footedness were clearly discernible but left footedness was indistinct. Right handedness was associated with dominant right upper limb and left handedness was associated with dominant left upper limb. Only right handers showed a dominant corresponding lower limb. Eyedness was related to handedness in males. Earedness and taste were associated with handedness in females. Smell had no relationship with handedness in both sexes. There was no interrelationship between handedness, footedness, eyedness, earedness, taste and smell.

Trophic changes following early unilateral injury to the brain

Measurements of the lengths of the feet and hands are reported for 15 neurologically normal children and for 17 children with left and 12 with right cerebral lesions. For those with left lesions the length of the left hand and foot significantly exceeded the right, while for those with right lesions the right hand and foot significantly exceeded the left. No significant foot or hand differences were found among the neurologically normal children. These findings demonstrate the association of atrophic limb-changes with unilateral brain lesions, and suggest that asymmetrical foot and hand growth may be a biological marker of early cerebral lesions.

Pedal asymmetries and handedness

The relationship between pedal asymmetries and handedness has been the subject of several investigations. Support for pedal asymmetries occurring in the normal population have been reported which are claimed to be a function of handedness and sex. If true, these asymmetries would confound the assessment of trophic changes due to localized brain injury. However, at least four attempts to replicate these results have failed. The present study was undertaken to reassess this hypothesis using more rigorous measurement of handedness and foot length with a more representative sample allowing for larger hand by sex groups than has been previously used. No differences in the direction of foot size were found regardless of hand or sex classification.

Sex, handedness and asymmetry of hand and foot length

Measurements of the length of the hands of 156 4-9 yr old children revealed a significant association among sex, handedness and direction of asymmetry of hand-length. Right-handed males have longer right than left hands while non-right-handed males have longer left than right hands (P less than 0.005). Females have a significant association also (P less than 0.005), with the direction of asymmetry the reverse of that found in males. No significant associations were found among the classification variables for foot-length measured at ages 4-9 or at birth.