, particularly dynamic knee valgus, is an important target to prevent and manage running-related pain and injury. The single-leg squat is a functional movement test commonly used by sports medicine practitioners to evaluate single-leg dynamic control of the trunk, pelvis, and lower limb. Lower limb movement
Lachlan E. Garrick, Bryce C. Alexander, Anthony G. Schache, Marcus G. Pandy, Kay M. Crossley and Natalie J. Collins
Benita Olivier, Samantha-Lynn Quinn, Natalie Benjamin, Andrew Craig Green, Jessica Chiu and Weijie Wang
The single-leg squat task is used as a rehabilitative exercise 1 , 2 or as a screening tool 3 , 4 for the functional movement of the lower limb. The presence of pathology influences the way in which the single-leg squat is performed. On performing the single-leg squat, individuals with
Maria K. Talarico, Robert C. Lynall, Timothy C. Mauntel, Erin B. Wasserman, Darin A. Padua and Jason P. Mihalik
The single-leg squat is a common clinical assessment evaluating lower extremity musculoskeletal and dynamic postural control deficiencies. 1 – 6 Standard practice for clinically assessing single-leg squat functional and balance performance involves visually observing movement patterns throughout
Hae-rim Han, Chung-hwi Yi, Sung-hyun You, Heon-seock Cynn, One-bin Lim and Jae-ik Son
except the side-lying hip abduction exercise. Moreover, the weight-bearing exercises replicate the functional activities of daily living better than the nonweight-bearing exercises. 6 Of the weight-bearing exercises, single-leg squats (SLS) represent one of the most commonly used hip
Lukas D. Linde, Jessica Archibald, Eve C. Lampert and John Z. Srbely
musculature. 4 This has been supported through gender differences in hip adduction and knee abduction angles (greater in females) during single-leg squats, 3 and subsequent improvements in these same outcomes have been reported during single-leg squats through neuromuscular training programs. 5
Matthew D. Freke, Kay Crossley, Trevor Russell, Kevin J. Sims and Adam Semciw
Although the single-leg squat (SLSq) is a reliable and valid clinical test frequently used by sports medicine practitioners to evaluate hip muscle function and dynamic control of the trunk and lower limb, 7 methodology is variable and there is a need for a standardized assessment technique. 8 A well
Timothy C. Mauntel, Barnett S. Frank, Rebecca L. Begalle, J. Troy Blackburn and Darin A. Padua
A greater knee valgus angle is a risk factor for lower extremity injuries. Visually observed medial knee displacement is used as a proxy for knee valgus motion during movement assessments in an attempt to identify individuals at heightened risk for injury. The validity of medial knee displacement as an indicator of valgus motion has yet to be determined during a single-leg squat. This study compared three-dimensional knee and hip angles between participants who displayed medial knee displacement (MKD group) during a single-leg squat and those who did not (control group). Participants completed five single-leg squats. An electromagnetic motion tracking system was used to quantify peak knee and hip joint angles during the descent phase of each squat. MANOVA identified a difference between the MKD and control group kinematics. ANOVA post hoc testing revealed greater knee valgus angle in the MKD (12.86 ± 5.76) compared with the control (6.08 ± 5.23) group. There were no other differences between groups. Medial knee displacement is indicative of knee valgus motion; however, it is not indicative of greater knee or hip rotation, or hip adduction. These data indicate that clinicians can accurately identify individuals with greater knee valgus angle through visually observed medial knee displacement.
Samantha N. Boudreau, Maureen K. Dwyer, Carl G. Mattacola, Christian Lattermann, Tim L. Uhl and Jennifer Medina McKeon
Functional exercises are often used in strengthening programs after lower extremity injury. Activation levels of the stabilizing hip muscles have not been documented.
To document the progression of hip-muscle activation levels during 3 lower extremity functional exercises.
44 healthy individuals, 22 women and 22 men.
Subjects, in 1 testing session, completed 3 trials each of the lunge (LUN), single-leg squat (SLSQ), and step-up-and-over (SUO) exercise.
Main Outcome Measures:
Root-mean-square muscle amplitude (% reference voluntary muscle contraction) was measured for 5 muscles during the 3 exercises: rectus femoris (RF), dominant and nondominant gluteus medius (GMed_D and GMed_ND), adductor longus (ADD), and gluteus maximus (GMX).
The RF, GMAX, and GMed_D were activated in a progression from least to greatest during the SUO, LUN, and SLSQ. The progression for the GMed_ND activation was from least to greatest during the SLSQ, SUO, and then LUN. Activation levels of the ADD showed no progression.
Progressive activation levels were documented for muscles acting on the hip joint during 3 functional lower extremity exercises. The authors recommend using this exercise progression when targeting the hip muscles during lower extremity strengthening.
Tina L. Claiborne, Charles W. Armstrong, Varsha Gandhi and Danny M. Pincivero
The purpose of this study was to determine the relationship between hip and knee strength, and valgus knee motion during a single leg squat. Thirty healthy adults (15 men, 15 women) stood on their preferred foot, squatted to approximately 60 deg of knee flexion, and returned to the standing position. Frontal plane knee motion was evaluated using 3-D motion analysis. During Session 2, isokinetic (60 deg/sec) concentric and eccentric hip (abduction/adduction, flexion/extension, and internal/external rotation) and knee (flexion/extension) strength was evaluated. The results demonstrated that hip abduction (r 2 = 0.13), knee flexion (r 2 = 0.18), and knee extension (r 2 = 0.14) peak torque were significant predictors of frontal plane knee motion. Significant negative correlations showed that individuals with greater hip abduction (r = –0.37), knee flexion (r = –0.43), and knee extension (r = –0.37) peak torque exhibited less motion toward the valgus direction. Men exhibited significantly greater absolute peak torque for all motions, excluding eccentric internal rotation. When normalized to body mass, men demonstrated significantly greater strength than women for concentric hip adduction and flexion, knee flexion and extension, and eccentric hip extension. The major findings demonstrate a significant role of hip muscle strength in the control of frontal plane knee motion.
Michael F. Joseph, Kristin L. Holsing and David Tiberio
Kinematic differences have been linked to the gender discrepancies seen in knee injuries. A medially posted orthotic decreases frontal and transverse plane motions in the lower extremity during ambulation, squatting and landing. This study investigated the effect of a medial post on amount and timing of lower extremity motions during a single-leg squat in male and female athletes. We hypothesized there would be differences in these kinematic variables dependent upon sex and post conditions. Twenty male and female athletes performed single-leg squats with and without a five degree full-length medial post. Maximum joint angles were analyzed using a two-way, repeated-measures analysis of variance to determine if the differences created by post condition were statistically significant, whether there were gender differences, or interactions. Differences in maximum motion values and the time at which they occurred were found between men and women at the hip, knee and ankle. The post decreased all frontal plane measures in both sexes and resulted in earlier attainment of maximum ankle eversion and delayed maximum knee valgus. A medially posted orthotic may be beneficial not only in limiting motion, but in affecting the time in which stressful motions occur.