Overhead Squat Assessment: Signs of Dysfunction

By Brent Brookbush DPT, PT, COMT, MS, PES, CES, CSCS, H/FS

For an introduction to the Overhead Squat Assessment (OHSA) including intent, validity, reliability, signs of dysfunction, analysis and set-up please review:

This article is includes a video, table with analysis and intervention recommendations, and relevant research for each of the 8 commonly noted signs during the OHSA.

Printable PDF of the Movement Assessment Template (including the OHSA):

Movement Assessment Template

Feet Flatten:

Research

Feet flatten has been correlated with tibialis posterior dysfunction (14-18), and selective activation/exercise for the tibialis posterior has been shown to have a positive effect on foot/ankle and lower extremity kinematics (19-20). Although these studies did not use the OHSA as an outcome measure, description of the sign”eversion/pronation” in these studies is similar to the description of the sign “feet flatten” used for the OHSA. Most of these studies referred to the “Navicular Drop Test”, which may be used as an objective interval measure in conjunction with the OHSA to monitor progress. In a study by Trimble et al. this sign, assessed with a lower extremity posture test was found to be a better indicator of tibial translation than recurvatum or thigh foot angle (84).

Feet Turn Out

Research:

Feet Turn Out - Only two studies have correlated feet turn-out with dysfunction. In a study by Winslow et al., feet turn out was correlated with a positive “Ober’s Test” (tensor fascia latae restriction/over-active) and knee pain (21), and in a study by Andrew et al., feet turn out was correlated with a functional varus and linked to knee osteoarthritis (40). However, other studies have shown a correlation between an increase in biceps femoris activity (a strong tibial external rotator) and knee dysfunction/pain (22, 23). In an interesting study by Hasegawa et al., biceps femoris stretching resulted in a relative increase in vastus medialis activity (23); this may be evidence that conservative treatment (exercise/manual therapy) may improve this impairment. It is worth noting, tibial external rotation may also be a component of “Knees Bow In” (functional valgus), as femoral internal rotation can be viewed as relative tibial external rotation.

Knees Bow In

Research:

Knees Bow In (functional valgus) – Research has correlated a functional valgus with a decrease in gluteus maximus and medius activity, sacroiliac joint dysfunction, excessive hip internal rotation and adduction, a loss of dorsiflexion, and excessive pronation (20, 24-33, 87-88). Studies have also correlated this sign of dysfunction with increased risk of anterior cruciate ligament (ACL) injury and patello-femoral pain (ACL) (24, 27, 28). Several studies have also noted the effectiveness of specific exercise intervention for correcting this dysfunction (20, 35-36). Although the OHSA is not used by name in any of these studies, in many of them, a squat or depth jump (LESS test) was used as to assess to measure the presence as knees bow in (referred to this sign as a “functional valgus” or “medial knee displacement”) (20, 24, 28 – 34)

Knees Bow Out

Research:

Knees Bow Out (functional varus) – In a study by Noda et al., this sign correlated with reduced ankle dorsiflexion and hip internal rotation using goniometric assessment (86). Further, there are several studies showing a correlation between functional varus (measured via gait or imaging) and knee osteoarthritis (37-39). Further, one study correlated an increase in varus loads on the knee with increased feet turn out and feet flatten during gait (40). One study showed that gait retraining (a conservative, exercise based approach) was effective for reducing a functional varus (41).

Excessive Forward Lean

Research:

Excessive Forward Lean – Two studies have shown a relationship between dorsiflexion restriction and excessive trunk flexion during squatting (and additional changes in kinematics) (32, 56). Two additional studies have demonstrated a decrease in gluteus maximus strength and activity related to ankle dysfunction (34, 57), which may partially explain the inability to maintain upright posture. Clinically, addressing dorsiflexion range of motion and addressing gluteus medius and gluteus maximus activity and strength have consistently resulted in positive outcomes.

Anterior Pelvic Tilt (Excessive Lordosis)

Research:

Anterior Pelvic Tilt (excessive lordosis) – This is an interesting sign relative to available research. Although it is not possible to find a single study that correlates all factors related to this sign, for example – an increase in lumbar lordosis, with a loss of hip range of motion, with an Anterior pelvic tilt, with altered motor control and low back pain – there are numerous studies that correlate 2 or more of these signs/symptoms (42-50). The strongest correlations likely exist between an Anterior pelvic tilt, low back pain and a loss of hip extension and internal rotation, and a relative reduction in transverse abdominis, multifidus, gluteus medius and gluteus maximus activity (42 – 50, 82). In one study by Cholewicki et al., a correlation was made between altered motor control and future low back pain (42); a rare study that implies dysfunction precedes pain! Several studies have shown that exercise is effective in the treatment of low back pain (and presumably an Anterior pelvic tilt) (51-55), especially long-term (55).

Arms Fall

Research:

Arms Fall – Although this sign would seem to indicate over-activity (or a loss of extensibility) of shoulder extensors, it is important that analysis of this sign considers extensors only from 180° of shoulder flexion, as performed during the OHSA. With some analysis and review of anatomy, the list of muscles generated could be summarized as “all shoulder internal rotators and the “posterior deltoid“. This list of muscles, has the added benefit of agreement with various texts that note “excessive internal rotation” in static posture in those exhibiting upper body postural dysfunctions (1-4, 9-10). Research has confirmed a portion of this list, as an increase in subscapularis and posterior deltoid activity has been observed in those experiencing shoulder pain (58, 59). However, there may be any easier method of validating this sign on the OHSA. “Arms fall” is nothing more than an inability to maintain 180° of shoulder flexion, and shoulder flexion goniometry has been shown to be a very reliable assessment (60-64). Although the OHSA may not be a good measure of progress due to the binary nature of assessment results; shoulder flexion goniometry may be used in conjunction with the OHSA as an objective interval measure to monitor progress. There is a gap in the research regarding this sign. There is no single study that correlates the sign “Arms Fall” with common shoulder pathologies (like shoulder impingement syndrome (SIS)), and further, no study that correlates how specific interventions may improve the sign “Arms Fall”. However, pain during end range shoulder flexion (as performed in the OHSA) is perhaps the most common complaint among those exhibiting symptoms of SIS, and there is a significant amount of research on external rotator activation (a commonly used intervention to treat SIS), and various studies have demonstrated that exercise is effective for the treatment of SIS (70 – 72).

Shoulders Elevate:

Research:

Scapula Elevate – This sign, like the sign above (Arms Fall), must be considered relative to functional anatomy. Although it may be presumed that “elevation” of the scapula is observed, closer examination will reveal this motion is actually elevation of the superior angle of the scapula around a relatively fixed glenoid fossa, in conjunction with sagittal plane motion of the scapula over the top portion of the rib cage. The resulting excessive joint actions are relative downward rotation and anterior tipping of the scapula. Once this discrepancy between observation and analysis is solved for, this sign is presumably valid based on agreement with research relative to shoulder dysfunction. Research by Lawrence et al., demonstrated relative downward rotation and an increase in anterior tipping of the scapula in those with shoulder pain (65). Further, research by Scavozzo et al found that swimmers with symptoms of shoulder impingement exhibited less than half the normal activity of the serratus anterior (an upward rotator and posterior tipper of the scapula) during the pull-through phase of stroke (58). An indirect relationship may also exist between this sign and a thoracic kyphosis, as a thoracic kyphosis has been correlated with shoulder impingement syndrome (66), and shoulder impingement syndrome with scapular dyskinesis (58, 65, 67 – 69). There is a significant amount of research to refine and support the use of scapular mobility techniques, serratus anterior activation and trapezius activation, and as mentioned above, exercise has been shown to be effective for the treatment of SIS (70 – 72).

The Next Step:

The next step in understanding the Overhead Squat Assessment is the recognition of "Clusters of Signs", also known as "Compensation Patterns."

These common clusters may be described by the Predictive Models of Movement Impairment discussed in the articles below:

Bibliography:

© 2017 Brent Brookbush

Questions, comments, and criticisms are welcomed and encouraged –