Increased Risk of Falling in Older Adults When Coordinating Obstacle Avoidance and Grasping

Area of Science:

• Biomechanics
• Gerontology
• Motor Control

Background:

• Falls in older adults are a significant public health concern.
• Simultaneous task execution, like walking and grasping, can challenge balance and increase fall risk.
• Understanding kinematic adaptations is crucial for fall prevention strategies.

Purpose of the Study:

• To investigate kinematic differences in obstacle avoidance and prehension tasks during simultaneous execution in older adults with a history of falls.
• To compare fallers and non-fallers across varying task difficulties.

Main Methods:

• Twenty-six older adults (fallers and non-fallers) participated.
• Tasks included: walking with obstacle avoidance, and combined walking, obstacle avoidance, and reach-to-grasp.
• Motion capture (Kinect v2) and hand tracking (Leap Motion Controller) analyzed gait and grasp kinematics.

Main Results:

• Fallers showed significant kinematic changes during combined tasks compared to non-fallers.
• These included reduced center of mass velocity, shorter step length, wider step width, decreased toe-obstacle distance, increased vertical foot clearance, and longer grasping movement time.
• Fallers employed a specific sequencing strategy, prioritizing grasping before obstacle clearance.

Conclusions:

• Older adult fallers exhibit distinct kinematic adaptations when faced with dual-task challenges involving obstacle avoidance and grasping.
• The observed sequencing strategy suggests a compensatory mechanism that may increase fall risk.
• These findings highlight the importance of considering complex motor tasks in fall risk assessment and intervention for older populations.