Effect of dynamic warm-up on ankle dorsiflexion and overhead squat performance

The purpose of this study was to first examine the effect of a dynamic warm-up (DWU) on both overhead squat (OHS) movement screen score and utilized ankle dorsiflexion (DF). Second, this study investigated the relationship between OHS movement screen scores and utilized ankle DF. Thirty-three university students, 21 males and 12 females, voluntarily participated in the project. Each subject attended two 60-minute testing sessions, one experimental (DWU) and one control condition (CON), approximately one week apart. Subjects’ OHS performance was scored according to Functional Movement ScreenTM (FMS) grading criteria; utilized ankle DF was recorded using 3D Motion Analysis. Subjects were given two practice sets; the first, with standard FMS instruction and the second with knowledge of the grading criteria. These data were collected at two time points (pre and post intervention) in each session. Reliability was reported using Intraclass Correlation Coefficients (ICC). Intra-rater reliability was very good (ICC - 0.87) and inter-rater reliability was excellent (ICC - 0.98). ANOVA revealed significant differences in subjects’ pre utilized ankle DF when categorized into groups based on OHS score (DWU – F(2, 30) = 4.89, p = 0.02; CON – F(2, 30) = 5.5, p = 0.01). Specifically, those differences lie between the highest (three) and lowest (one) scoring groups (DWU – p = 0.01; CON – p = 0.01). A significant proportion of subjects’ OHS Score improved, as compared to the control group (X2 (1, N=41) = 11.4, p = 0.001). However, there were no main effects of group (F[1, 32] = 0.03, p = 0.86) or time (F[1, 32] = 0.13, p = 0.73) on utilized ankle DF. The researchers conclude that, within this sample, OHS Score is not a sensitive discriminator of utilized ankle DF and that some subjects’ scores would be more representative of their true movement capacity potential with the inclusion of a DWU. These results do not provide clear evidence as to what the OHS movement screen is assessing. Further research into validating this and additional movement screen component tests is warranted.