Neurophysiological comparison between the Sit-to-Stand test with the 6-Minute Walk test in individuals with COPD

The Sit-to-Stand test (SST) is accepted and utilized during functional assessments of COPD patients, along with the 6-Minute Walk test (6MWT). Since there is a lack of evidence in literature regarding the neurophysiological effectiveness of SST compared to 6MWT, the present study is justified with the purpose of assessing the neurophysiological effectiveness of SST in comparison to the 6MWT during the functional assessment of such patients, once it is known that both tests are good predictors of functional state.

Fourteen patients with moderate to severe COPD randomly performed the 6MWT and the SST with a 30-minute interval in between tests. Blood lactate was collected along with the median frequency (MDF), obtained with the electromyography of the muscles rectusfemoris (RF), vastus lateralis (VL), tibialis anterior (TA), and soleus (SO) for the comparison of the neurophysiological effectiveness.

The results of the blood lactate concentration during rest and at the end of the functional tasks along with the results from the angular coefficient (AC) obtained from the median frequency were analyzed with the Student t test. The initial and final values obtained from SST and 6MWT were compared within each activity, along with the comparison between the initial and final values for each functional test. A significant difference (p = 0.0005) was only verified between the initial and final values of SST.

We found neurophysiological correlation between both tests which enabled us to suggest that SST may determine functional status as easily as the 6MWT in regard to neurophysiological effectiveness.