Research of the factors affecting lower extremity functional performance tests

The purpose of this study was to investigate the factors affecting modified star excursion balance test (MSEBT), weight bearing lunge test (WBLT) and step down test (SDT) which are commonly used to evaluate lower extremity functional performance in the clinic. Thirty males, 21 females, total 51 healthy individuals were included in this study (Age: 22.74±1.93 years; Body Mass Index : 22.52±2.29 kg /m2). The factors chosen for SEBT were shoe use, hand position, lower extremity length and ankle dorsiflexion range of motion (DFROM); for WBLT, Gastrocnemius and Soleus flexibility, leg length and tibial inclination angle; for SDT, DFROM, Quadriceps muscle strength, Quadriceps muscle endurance and dynamic valgus angle. Linear regression and repeated measures of ANOVA were used for statistical analysis. The effects of shoe use, hand position and lower extremity length on MSEBT were found significant (p<0.001) but effect of DFROM was found significant in only anterior direction (p<0.05). Gastrocnemius flexibility (r= 0.56, p<0.001), Soleus flexibility (r=0.44, p=0.001) and tibial inclination angle (r= 0.50, p<0.001) were found correlated with WBLT but leg length was not correlated with WBLT (p>0.05). There was moderate correlation between Quadriceps muscle strength and SDT (r= 0.51, p<0.05). No correlation was found between DFROM, Quadriceps muscle endurance and dynamic valgus angle and SDT (p>0.05). As shoe use, hand position and lower extremity length affect the MSEBT results, standard prosedure is needed for using this test. As an alternative to tape measure in WBLT, tibial inclination angle measurement can be used. When evaluating step down performance, quadriceps strength should be considered.