| Objective: This study employed a three-dimensional gait analysis system to examine the lower extremity biomechanical characteristics associated with normal-speed walking in elderly individuals at the pre-frailty stage. Methods: This investigation was designed as a single-center, cross-sectional study involving 68 eligible participants (34 pre-frail elderly individuals and 34 matched non-frail counterparts) selected through propensity score matching. Comprehensive demographic data were collected from subjects, alongside assessments using the Fried frailty scale, mini-mental state examination (MMSE), Berg balance scale（BBS）, and simple physical performance battery (SPPB). Simultaneously, a three-dimensional gait analysis system was employed to capture dynamic images, enabling the quantification of overall gait and the extraction of corresponding lower limb kinematic parameters. A correlation analysis was subsequently performed to examine the relationship between these gait parameters and established measures such as the BBS, SPPB, and MMSE, thereby elucidating the abnormal gait characteristics observed in the elderly individuals during the pre-asthenic stage. Results: Compared to their non-frail counterparts, those in the pre-frailty group exhibited notable differences in gait parameters: (1) spatiotemporal metrics indicated reduced square step speed, shortened step length, and prolonged double support phase duration (P<0.05); (2) gait variability score (GVS), pelvic tilt angle, hip adduction/abduction angles, hip flexion/extension angles, hip rotation angle increased while gait profile score（GPS）rose and gait deviation index (GDI) decreased (P<0.05); (3) Kinematic analyses revealed that during initial swing phase toe-off there was an increase in hip flexion/extension angle at terminal swing phase foot contact there was an increase in hip flexion/extension angle while knee flexion/extension angle decreased along with maximum knee flexion/extension values. Additionally observed were decreases in maximum ankle dorsiflexion values coupled with increases in minimum plantarflexion values leading to reduced range of motion (ROM), and the difference was statistically significant (P<0.05). Conclusion: This resear-ch suggests that the abnormal gait of pre-frail elderly people might be associated with body balance and the coordinated movements of joints such as the feet, ankles, knees, and hips, and presents compensatory phenomena in temporal and spatial parameters and the kinematics of lower limb joints. Correlation analyses between identified gait parameters and fall incidents indicate that changes characteristic of a pre-asthenic state can lead to observable impairments such as slower pace or diminished ankle mobility during ambulation or daily activities. Consequently, implementing gait analysis could serve as a valuable tool for clinical frailty screening. |
