The project aims to investigate the validity, and reliability of outcome measures of muscle strength, functioning (gait, balance, and fine motor skills), physical activity, and patient-reported outcome measures of functioning (gait, balance, and fine motor skills), and daily living among patients with polyneuropathy. Further, the project aims to compare physical activity and patient-reported outcome measures of functioning (gait, balance, and fine motor skills), and daily living among patients with polyneuropathy with physical activity and patient-reported outcome measures of functioning (gait, balance, and fine motor skills) and daily living in healthy adults.