Cognitive resource allocation in deaf individuals: Any implications for injurious falls?

Abstract Background: This mixed-methods pilot study was designed to investigate the possible risk of injurious falls in American Sign Language (ASL) users. Sign language is highly cognitive, yet the impacts of concurrent cognitive load among ASL users are unclear. Research on dual task of walking and signing may provide functional and critical information to prevent injurious falls in the Deaf community where ASL is a primary language. The current study was designed to investigate the potential fall risks due to the simultaneous activity of walking and signing among ASL users. Methods: Five ASL users (4 native ASL users and 1 ASL interpreter) participated in the study. Participants completed three walking tasks under a different cognitive load: Walking without signing, walking while retelling the Cinderella story using ASL, and walking while having a conversation in ASL. Four gait parameters (i.e., functional ambulation profile (FAP), velocity, stride length (SL), and double support time [DST]) were measured using the GAITRite© Portable Walkway System from CIR Systems, Inc. Following the walking tasks, a semi-structured interview was conducted to understand participants’ subjective perception of potential fall risks associated with the dual task. Results: The one-way analysis of variance with the within-subject factor of cognitive load and the Tukey post hoc test revealed participants’ gait stability decreased as the cognitive load increased, evidenced by the significant decrease in FAP scores, SL, and velocity, and increase in DST. Through the qualitatively thematic analysis of the interview, three themes were identified: Walking and signing is a common experience in the Deaf community; signers maintain compensatory strategies; and cultural rules to minimize fall risks while walking and signing exist. Discussion: While the sample size was limited, objective gait deterioration was found in all participants which implies increased fall risks. In addition, participants stated cultural rules and strategies that evidence the presence of such gait changes. The results from this pilot study suggest that while the risk of falls is underperceived, the impact of such an occurrence is felt throughout this sample of Deaf community members. Further investigations in this area are warranted. Conclusion: This pilot study reveals that walking and signing concurrently may increase fall risk among ASL users, as evidenced by objective gait deterioration and participants’ noted compensatory strategies. These findings emphasize the need for greater awareness and further research on fall prevention approaches within the Deaf community.