Age-Related Change of Head Control in Response to Postural Perturbations

Research Objectives: To explore if older adults, particularly those over 75 years, have more zero-crossings to restore head stabilization than young adults after postural perturbations.

Design: Cross-sectional study.

Setting: Laboratory setting.

Participants: A convenient sample of 57 healthy participants without a current or past history of neck-related dysfunction, trauma, deformities, and uncontrolled balance issues were recruited. They were grouped by age: Young (18-30 yrs, age: 22.3±3.8), Young-Old (60-74 yrs, age: 67.2±3.8), and Old-Old (>75+ yrs, age: 81.1±5.3).

Interventions: Not applicable.

Main Outcome Measures: Accelerometers (Delsys) were attached on the forehead and C7 of participants as they experienced the unexpected platform translations (Neurocom). A total of six trials were performed in random order including three anterior and posterior perturbations. The linear head acceleration in the vertical, anteroposterior, and mediolateral axis were extracted. A custom Matlab code computed the resultant head acceleration, detected the head re-stabilization time of each trail, and determined the number of zero-crossings during the head re-stabilization of three axes.

Results: Significant less zero-crossings in the Young group were noted in the vertical (p = 0.011, η2 = 0.07) and AP (p = 0.030, η2 = 0.05) axes of posterior platform translation. Despite no statistical differences found in other conditions, a trend of increased zero-crossing with aging was suggested. The Old-Old group consistently showed the greatest number of zero-crossings across all the conditions.

Conclusions: Older adults appear to recruit a different head stabilization strategy in response to postural perturbations. The oldest age group (over 75 years) seems to show more vigorous neuromuscular control to restore the postural stabilization in the head-neck segment after the perturbation than the younger counterparts.

Author(s) Disclosures: Authors declared that none of us had relevant or material financial interests that relate to the research described in this research project.