Consistency of hand use and accidents with injury

In praise of ambidexterity: How a continuum of handedness predicts social adjustment

This paper estimates the relationship between handedness and social adjustment in children. In addition to binary measures of hand preference, we also use a continuous measure of relative hand skill. Outcomes at ages 7, 11 and 16 are studied. The data used is the British 1958 Birth. Using a partially linear semi-parametric regression estimator, it is shown that non-right-handedness (as hand preference) is associated with poorer social adjustment but this effect weakens as individuals age into their teens. The continuous measure of hand skill has a non-monotonic effect on social adjustment with poorer social adjustment in the tails of the continuum. The results are consistent with a growing body of evidence which shows that it is the consistency or degree of laterality (rather than direction) that is important for many outcomes.

Patterns of hand preference and unintentional injuries among Indian attempted hand switchers and hand non-switchers

This study examines the patterns of hand preference and unintentional injuries of attempted hand switchers and hand non-switchers. Data were collected from 3698 participants in Kharagpur, India, on measures of hand preference, hand switching, and unintentional injuries. The direction of left- or right-handedness was on the basis of hand used for the item "writing on paper" and the degree of handedness was based on the average score of remaining items in the handedness inventory. Results reveal that, among attempted hand-switchers, learned right-handers were not right-sided in hand continuum as the natural right-handers, but left-handers were left-sided as natural left-handers. With increasing age the learned right-handers become less right-sided and natural right-handers become more right-sided. Females (males) are found to be more right-handed than males (females) among learned right-handers (natural right-handers). On the direction of handedness, the learned right-handers have more than twice the risk of unintentional injuries than the natural right- and left-handers. On degree of handedness, the use of inconsistent left and both hands among natural left-handers, the use of inconsistent right and both hands among natural right-handers, and the use of weak right hand among learned right-handers increase their vulnerability to unintentional injuries. Any deviation from the genetic make-up in hand use elevates the risk of unintentional injuries, suggesting that one should not change the biological hand.

The relationship between hand preference consistency, health, and accidents in a sample of adults over the age of 65 years

As a result of the Coren and Halpern (1991) hypothesis that left hand preference may be associated with decreased survival fitness, there has been interest in exploring the relationship between hand preference and indices of health status. In a series of studies of university-aged adults, Hicks and his colleagues found a higher prevalence of accidental injuries, falls, and sleep problems among individuals with mixed, rather than left, hand preference. They argued that hand preference consistency, not side, may be a marker for possible reduction in health and well-being. We looked at the relationship between hand preference consistency and the prevalence of sleep problems, accidental injuries, falls, injuries from falls, and the prevalence of autoimmune and other illnesses in a sample of 1277 adults between the ages of 65 and 100 years. Of those participants who reported a recent fall, mixed-handers were more likely to report a higher number of injuries from these falls when compared to the reports of consistent-handers. In contrast to the previous findings of Hicks et al., and highlighting the value of including broader age ranges, all other comparisons showed no differences between the two hand preference types.

Laterality and accident proneness: a study of locomotive drivers

This study attempted to find the association between four measures of laterality (handedness, footedness, eyedness, and earedness) and accident proneness in locomotive drivers. The Sidedness Bias Schedule was administered to a sample of 80 locomotive drivers to ascertain their preferential bias. Their accident records were also available. Positive correlations were mostly found between the measures of hand, foot, ear, and eye dominance. Analyses suggested that there was a higher accident rate among left-handers and left-footers, with multiple regression unable to determine whether handedness or footedness was related more strongly to accident proneness. However, it was clear that accident rate was primarily associated with direction of lateralisation, and not with degree of lateralisation. Drivers with left-handedness were more likely to be involved in accidents, and it is possible that that may be related to the design of the locomotive cabs.

Side bias and accidents in Japan and India

The purpose of this study was to examine (a) the incidence of leftward bias for paired organs (hand, foot, eye, and ear) in India (n = 418) and Japan (n = 697), and (b) the incidence of accident amongst individuals with leftward, rightward, and no bias across countries. The impetus for the study was obtained from a speculation that individuals with leftward bias commit more accidents than their counterparts. Data were collected with the help of a questionnaire on side bias, along with a check-list on accidents (included in the questionnaire). Results showed that participants from these two countries did not differ in terms of leftwardness for any of these forms of side bias. Left-handers were found to commit more accidents in India but not in Japan. Reanalysis of data in terms of left-, mixed-, and right-handedness indicated that mixed handers committed more accidents than extreme (left- + right-) handers in Japan but not in India.

Consistency of hand use and frequency of colds among college students

The self reported annual frequencies of colds were assessed for two groups of 37 students each who were either consistent or inconsistent in the use of their hands. These data indicated that the inconsistent hand use group reported significantly more colds than their consistent hand use peers.

Consistency of hand use and sleep problems

In this study, we measured the relationship between the consistency of hand use and three symptoms of insomnia, i.e., delayed sleep onset, frequent awakenings during sleep, and trouble returning to sleep after an awakening. For each of these insomnia-related symptoms, university students who were classified as inconsistent in the use of their hands (n = 30) were significantly more likely to report problems than their consistent hand-use peers (n = 30). These data were discussed both in relation to the literature on handedness classification and sleep problems and the emerging literature on consistency of hand use and health-related problems.

Consistency of hand use and frequent falls

We examined relationships between consistency of hand use and falling in groups of right-handed university undergraduates who were either consistent (n = 45) or inconsistent (n = 32) in the use of their hands. A scoring procedure developed for the Briggs-Nebes Handedness Scale permitted us to classify individuals as consistent or inconsistent in the use of their hands. The inconsistent group was 2.81 times more likely to have experienced frequent falls during the last 12-mo. period and was 1.64 times more likely to rate themselves higher on proneness to falling. These data suggest that inconsistent hand use may be a sign of a developmental inconsistency in motor coordination.

Consistency of hand use, exercise, and sports-related injuries

In this study, we examined the relationships between the consistency of hand use, exercise, and sports-related injuries as an indirect test of the hypothesis that the consistency of hand use is a reflection of general motor coordination. As we predicted, the consistent hand-use group (n = 23) exercised more, were more likely to follow a regular exercise schedule, and reported having experienced more sports-related accidents than their inconsistent hand-use peers (n = 23).