Dynamics of self-injurious behaviors

Area of Science:

• Neuroscience
• Developmental Psychology
• Biomechanics

Background:

• Self-injurious behavior (SIB) is a complex issue often associated with developmental disabilities.
• Head-banging is a common form of SIB, necessitating detailed biomechanical analysis.
• Understanding the dynamics of SIBs is crucial for developing effective interventions.

Observation:

• A case study focused on an 8-year-old girl with profound intellectual disability and autistic disorder exhibiting head-banging.
• Dynamic analysis of videotapes was employed to study arm movement trajectories and impact forces.
• Measurements included motion with one hand, two hands (inphase and antiphase), and with a protective helmet.

Findings:

• The head-banging movements demonstrated a high degree of cycle-to-cycle consistency in their qualitative dynamics.
• Arm motions using one hand were faster than those using two hands (inphase and antiphase).
• Motions while wearing a helmet were approximately 25% faster than those without a helmet. The impact forces of the self-injurious behaviors (SIBs) were found to be at the lower end of forces generated in professional boxing or karate impacts when expressed as a percentage of body weight.

Implications:

• The consistent dynamics suggest predictable patterns in SIBs, potentially aiding in targeted behavioral interventions.
• Understanding the biomechanics of head-banging can inform the design of protective equipment and therapeutic strategies.
• The findings provide a quantitative basis for assessing the physical forces involved in SIBs, contributing to risk assessment and management.