This study is being done to measure real-world motions and forces in the spine during everyday activities. This information will be used to develop and validate a computer model of how the spine moves and determine injury risk.

Kinematic motion data will be collected at 120 Hz using a 14-camera Real Time Motion Analysis system. Cortex software (Motion Analysis Corp., Rohnert Park, CA) will be used to visualize the data during physical activities. A developed Matlab code will be used for data analysis. Statistical parametric mapping (SPM) will be used to collect the entire kinematic motion waveforms to compare motion profiles of different individuals. Also, the peak values for each activity will be captured for statistical analysis. Muscle response and electrical activity, which will be used to estimate muscle forces, will be recorded during gait analysis from the paraspinal lumbar muscles using an EMG system. Surface electrodes will be attached to the lumbar spine. EMG data will be collected at 2400 Hz. For each participant, the investigators will record five trials per activity.

Additionally, gait speed as well as static and dynamic balance will assess. Knee and grip strength will also be measured. Finally, physical activity levels will be assessed both objectively and subjectively.

Inclusion Criteria:

• Age 50 and over
• Ability to perform trunk flexion, lateral bending, and axial rotation, as well as lift at least 5 pounds of weight from the floor

Exclusion Criteria:

• Spinal pathologies
• Physiological and neuromuscular disorders
• BMI>35
• Knee or hip replacement in the past 12 months
• Use of assistive devices
• Frailty: with FRAIL score of 3 or greater

Mayo Clinic's elderly adult patients or residents of Rochester MN with minimum age of 50 years.

Data will be stored in the Motion Analysis Lab at Mayo Clinic Rochester.