Comparison of Lower Extremity Kinematics during the Overhead Deep Squat by Functional Movement Screen Score

Abstract

It is unclear if the Functional Movement Screen (FMS) scoring criteria identify kinematics that have been associated with lower extremity injury risk. The purpose was to compare lower extremity kinematics of the overhead deep squat (OHDS) during the FMS between individuals who were grouped on FMS scoring. Forty-five adults who were free of injury and without knowledge of the FMS or its scoring criteria (males = 19, females = 26; height = 1.68 0.08 m; mass = 70.7 7 13.0 kg). Three-dimensional lower extremity kinematics during an OHDS were measured using a motion capture system. One-way MANOVA was used to compare kinematic outcomes (peak hip flexion angle, hip adduction angle, knee flexion angle, knee abduction angle, knee internal rotation angle, and ankle dorsiflexion angle) between FMS groups. Those who scored a 3 had greater peak hip flexion angle (F2,42 = 8.75; p = 0.001), knee flexion angle (F2,42 = 13.53; p = 0.001), knee internal rotation angle (F2,42 = 12.91; p = 0.001), and dorsiflexion angle (F2,42 = 9.00; p = 0.001) compared to those who scored a 2 or a 1. However, no differences were found in any outcome between those who scored a 2 and those who scored a 1, or in frontal plane hip or knee kinematics. FMS scoring for the OHDS identified differences in squat depth, which was characterized by larger peak hip, knee, and dorsi- flexion angles in those who scored a 3 compared with those who scored 2 or 1. However, no differences were found between those who scored a 2 or 1, and caution is recommended when interpreting these scores. Despite a different FMS score, few differences were observed in frontal or transverse plane hip and knee kinematics, and other tasks may be needed to assess frontal plane kinematics.

Three-Dimensional Kinematics and Kinetics of the Overhead Deep Squat in Healthy Adults: A Descriptive Study

“…Normal mean (± standard deviation) kinematic and kinetic data figures were created in the most current Visual 3D (Vx64) software and graphed as the percent squat from 0 to 100%. This is consistent with time-normalized reporting of the OHDS used by Heredia et al where graphic presentation is reported in a percentage from 0 to 100% [15].…”

“…Sagittal and transverse plane motion during the squat followed a highly predictable pattern and demonstrated the least variability. The mean peak knee flexion of approximately 123 degrees was comparable to that reported by others [10,15]. However, our data did not distinguish subjects by FMS TM score, whereas Butler and Heredia found that participants with FMS TM scores of 1 and 2 demonstrated less peak flexion than those with an FMS TM score of 3 [10,15].…”

“…Since we incorporated the multi-segment OFM, we expected to see some differences in the magnitude of sagittal plane mobility at the ankle. For example, although the maximum dorsiflexion approximated 30 degrees, which was similar to Butler et al, Heredia et al reported approximately 42 degrees [10,15]. The differences reported by Heredia et al are likely related to the marker clusters and the simplified foot model used by that group.…”

“…When the total sagittal plane motion of the forefoot, hindfoot, and talocrural joints is added together, Heredia et al's. findings were approximated [15]. This indicates that often overlooked intrinsic foot mobility is key to achieving full squat depth and should be considered clinically.…”

“…The FMS TM , an aggregate of seven tests, was developed to identify movement asymmetry and/or dysfunctional movement patterns of the trunk, pelvis, and upper and lower extremities [10,23]. As a component of the FMS TM , the OHDS is a performance-oriented test of mobility and stability of multiple joints and appears to contribute the largest proportion of variance to the composite FMS TM score [10,15]. Despite the obvious need for multiplanar controlled mobility for the completion of a full, painfree deep squat, there exists no comprehensive control dataset of the 3D joint movement elements of the OHDS.…”