The measurement properties of the Lean-and-Release test in people with incomplete spinal cord injury or disease

Abstract

Objective

To evaluate test-retest reliability, agreement, and convergent validity of the Lean-and-Release test for the assessment of reactive stepping among individuals with incomplete spinal cord injury or disease (iSCI/D).

Design

Multi-center cross-sectional multiple test design.

Setting

SCI/D rehabilitation hospital and biomechanics laboratory.

Participants

Individuals with motor incomplete SCI/D (iSCI/D).

Interventions

None.

Outcome Measures

Twenty-six participants attended two sessions to complete the Lean-and-Release test and a battery of clinical tests. Behavioral (i.e. one-step, multi-step, loss of balance) and temporal (i.e. timing of foot off, foot contact, swing of reactive step) parameters were measured. Test-retest reliability was determined with intraclass correlation coefficients, and agreement was evaluated with Bland–Altman plots. Convergent validity was assessed through correlations with clinical tests.

Results

The behavioral responses were reliable for the Lean-and-Release test (ICC = 0.76), but foot contact was the only reliable temporal parameter using data from a single site (ICC = 0.79). All variables showed agreement according to the Bland–Altman plots. The behavioral responses correlated with scores of lower extremity strength (0.54, P<0.01) and balance confidence (0.55, P < 0.01). Swing time of reactive stepping correlated with step time (0.73, P < 0.01) and cadence (−0.73 P < 0.01) of over ground walking.

Conclusions

The behavioral response of the Lean-and-Release test is a reliable and valid measure for people with iSCI/D. Our findings support the use of the behavioral responses to evaluate reactive stepping for research and clinical purposes.

Trial registration

ClinicalTrials.gov identifier: NCT02960178.

Key Words:

• Spinal cord injuries
• Postural balance
• Validation study