Oxygen uptake kinetics differentiates two from six minute walk tests in lower extremity prosthesis users

Area of Science:

• Biomechanics
• Exercise Physiology
• Prosthetics

Background:

• The six-minute walk test (6MWT) is commonly used to assess functional capacity in individuals with lower limb prosthesis (iLLA).
• The two-minute walk test (2MWT) is shorter and may be considered as an alternative, but its validity as a proxy for the 6MWT in iLLA requires investigation.

Purpose of the Study:

• To compare oxygen uptake kinetics and biomechanical parameters during the 2MWT and 6MWT in iLLA and unimpaired individuals.
• To determine if the 2MWT can serve as a valid proxy for the 6MWT in iLLA.

Main Methods:

• Participants (iLLA and unimpaired) performed both 2MWT and 6MWT.
• Oxygen uptake (VO2), heart rate (HR), and spatio-temporal parameters were recorded.
• Repeated measures factorial ANOVAs were used for statistical analysis.

Main Results:

• No significant differences in VO2 or HR were observed between groups during either test.
• iLLA walked shorter distances but had similar cadence and total steps compared to unimpaired individuals.
• iLLA exhibited greater stance ratios and shorter stride length; stride length was also shorter during 6MWT compared to 2MWT in iLLA.

Conclusions:

• While the 2MWT strongly predicts 6MWT performance in both groups, significant physiological and biomechanical differences were noted.
• The 2MWT should not be used as a substitute for the 6MWT in individuals using lower limb prostheses.