Relative and absolute reliability of the new "Step-Ex" step-execution test in elderly people with and without balance problems.

PURPOSE

To evaluate the relative and absolute test-re-test reliability of a new step-execution test, "Step-Ex", for clinical use in elderly with and without balance problems.

METHOD

Test-re-test design to assess intrarater reliability. Thirty-four healthy community-dwelling elderly (65-87 years), 16 with balance problems, were tested twice two weeks apart. Step-Ex consists of two portable force platforms that register vertical ground reaction forces connected to a computer for easy detection of temporal events and phases (reaction-, preparation-, stepping- and step execution phase). Standing with one foot on each platform, the subjects were given a tactile stimulus on the heel to initiate rapid steps forward.

RESULTS

Test-re-test agreement was good to very good: ICC(2)(.6) 0.83-0.87 (without balance problems) and 0.71-0.83 (with balance problems) with no apparent systematic differences between the tests. The SEM, i.e. the smallest detectable change that may indicate a real clinical improvement for a group of individuals was small, 4.6-8.6%. The smallest real difference, representing the smallest change that reveals clinical improvement for a single individual, was 13-24%.

CONCLUSION

Step-Ex is a highly reliable instrument and can be recommended as an outcome measure evaluating the effects of balance training in elderly people with and without balance deficits.

IMPLICATIONS FOR REHABILITATION

• Balance deficits are common in the elderly population. • To evaluate the effects of treatment or changes over time it is of great importance to have reliable instruments. • Step-Ex is a highly reliable instrument and can be recommended as an outcome measure evaluating the effects of treatment or changes over time in elderly people with and without balance deficits.