There was a recent Facebook post from a left-hander who had injured his left hand. He was seeking advice about starting to use his right hand because of the discomfort associated with left-hand use. Another left-hander responded, “Don’t let anyone force you to be a righty!”. This exchange reminded me of a study I published in 1995 where I systematically explored what happens to hand use during and after a temporary hand injury. ¹ My research was conducted in British Columbia, Canada. Hand injuries were common in BC at that time because of the large labor participation in the logging and fishing industries.

I contacted over 400 people who were treated for and recovered from a temporary hand injury to one hand during the five-year period before data collection. The injury types ranged from nerve, tendon and ligament damage to injuries specific to the wrist or fingers with an average recovery period of 1 to 6 months. I measured the behaviors of eating with a fork without a knife, throwing a ball, cutting with scissors, writing and striking a match to light it. Participants rated their hand use on each of these items as they recalled it before the hand injury, during the recovery period, and after recovery from the hand injury. The 5-point rating scale ranged from ‘always use the right hand’ to ‘always use the left hand’.

Not surprisingly, individuals with preferred hand injuries showed the largest change to non-preferred hand use during the injury recovery period. There was an interesting difference based on handedness type. Right-handers shifted to left-hand use only when they injured their preferred right hand. Left-handers with both left- and right-hand injuries showed shifts to the opposite hand during the injury recovery period. This pattern may reflect the fact that left-handers are more likely than right-handers to have acquired skills with both the right and left hands. For a left-hander, an injury to either hand causes behavioral disruption and a switch to opposite hand use during the recovery period.

I also examined handedness patterns after the person had recovered from the hand injury. Any shifts in handedness side during the recovery period were not sustained. People reverted back to their pre-injury hand use on all five of the behaviors I measured in the study. Temporary switches in hand use during a hand injury recovery period do not result in permanent changes in handedness. A left-hander with a left-hand injury will not become a ‘righty’ if he/she temporarily favors the right hand while recovering from the injury. A study I published in 1993 found that left-handers were no more likely to suffer from hand injuries than right-handers. ² Individuals who were strong right- or left-handers were more likely to injure their preferred hands when compared to people who indicated the ability to use both hands. In other words, one is more likely to injure the hand that is used consistently whether it be the right or the left hand.

The study of individuals with temporary injuries of one hand reveal that hand use behaviors are adaptable and changeable in the short term. This is the case for both right- and left-handers. Unfortunately, there are only a few published studies exploring forced handedness change in the injury context. Maybe this blog post will encourage the current generation of handedness researchers to explore the effect of hand injury on handedness behaviors.

¹Porac, C. (1995). Genetic vs. environmental contributions to human handedness: Insights gained from studying individuals with unilateral hand injuries. Behavior Genetics, 25, 447-455.

²Porac, C. (1993). Hand preference and the incidence of accidental unilateral hand injury. Neuropsychologia, 31, 355-362.