The validity of the 5 and 10 sit-to-stand test

Background: To rise from a sitting to a standing position and to sit down again are categorized as basic transitional movements, and are performed approximately 50 times a day. The sit-to-stand test (STS test) evaluates strength in lower extremities, neuromuscular functions, balance and vestibular function. There are several versions of the test; two examples of these are the 5STS and 10STS tests. For people with multiple sclerosis (MS), only the 5STS test has been validated. A potential difference between the 5STS and 10STS test can be that more repetitions require more muscular endurance and, thus, the 10STS test will reveal impaired muscular endurance more than the 5STS test.Aim: The aim was to evaluate the validity for the 5STS and 10STS tests for people with moderate MS.Methods: Forty-seven people with MS with a limited ( 20 m) walking ability were included (32 women; 30 secondary and 12 primary progressive MS). The STS tests were slightly modified for safety reasons; instead of crossing arms over the chest, hand support was allowed. Time was taken from the starting position sitting using the command ‘Go’ and stopped when the participant sat down again after completing the 10th standing position. An intermediate time was taken when sitting down after the fifth standing position (5STS test). Validity was evaluated using the timed up and go test (TUG), 10 minute walk test (10MWT), 2 minute walk test (2MWT) and the Berg balance scale (BBS); calculated using Spearman’s rank correlation. Correlations exceeding 0.60 were considered strong.Results: Strong correlations (r=0.60–0.70) were found between the 5STS and 10STS test and the TUG, the 10 MWT, the 2MWT and the BBS. The correlation between the 5STS and 10STS test (r=0.86) indicates that the tests measure slightly different abilities. A slightly stronger correlation was found between the 5STS and BBS (r=−0.68) compared to the 10STS and BBS (r=−0.61). The correlations were stronger between the 10STS and the walk tests compared to the 5STS and walk tests. The high correlation between the 10STS and the 2MWT (r=0.70) can possibly be explained by a muscular endurance component.Conclusion: Both the 5STS and 10STS test are valid for people with moderate MS but they do not measure the exact same ability