Characterizing Practice Effects in Performance-Based Tests Administered to Users of Unilateral Lower Limb Prostheses:...

Area of Science:

• Rehabilitation Medicine
• Biomechanics
• Prosthetics and Orthotics

Background:

• Performance-based tests are crucial for assessing physical capability in lower limb prosthesis (LLP) users.
• Practice effects, improvements from repeated testing, can compromise the validity of these assessments.
• Limited research has addressed practice effects in LLP users.

Purpose of the Study:

• To characterize the occurrence, time-course, and magnitude of practice effects in commonly used performance tests for LLP users.
• To evaluate the impact of practice on the Timed Up and Go (TUG), Four Square Step Test (FSST), and 10-m Walk Test (10mWT).

Main Methods:

• Secondary analysis of data from a multisite, repeated-measures study involving 60 ambulatory LLP users.
• Quantified practice effects by analyzing cumulative trial-by-trial performance records.
• Calculated occurrence, time-course (number of trials to reach consistent performance), and magnitude (performance improvement) for each test.

Main Results:

• Practice effects were observed in 45% to 76% of participants across the TUG, FSST, and 10mWT.
• The FSST showed a significantly higher proportion of participants with practice effects compared to the 10mWT.
• Significant practice effect magnitudes were found for the FSST (1.6s, 16% improvement) and TUG (1.4s, 13% improvement).

Conclusions:

• The FSST, TUG, and 10mWT are susceptible to practice effects in users of lower limb prostheses.
• Unaddressed practice effects can mask true differences in walking and balance abilities.
• Modifications to testing protocols may be necessary to ensure the accurate clinical application of these performance measures for LLP users.