This study evaluated the sensitivity of primary task performance, subjective rating and some physiological indexes in assessing tracking mental workload.

A quantitative value representing the subjective rating or opinion of users reacting to seeing or using a system, as opposed to performance measures like task completion time or number of errors.

The primary outcome was Short Form (SF)-36, and the secondary outcomes were the verbal rating scale of low back pain and leg numbness, walking distance, subjective improvement, and satisfaction.