16 I Fall 2018 www.anjc.info Legislative Update Legal Ease Chiro Assist TECHNIQUE Council REHABILITATION Council Legal Q&A By Dr. Donald C. DeFabio Chair, ANJC Physical Rehabilitation and Performance Council The back squat is considered a foundational exercise for sport performance and exercise. It engages major muscles in movement patterns necessary for ADLs, to reduce injury risk as well as physical activity. The back squat can be used as an assessment for neuromuscular control, strength, stability and mobility within the kinetic chain – exactly the arena for chiropractic doctors doing active care. Myer and his team have proposed that the unloaded back squat can also be used as a dynamic screening tool to isolate functional deficits and serve as a guide in rehabilitation and corrective exercise prescriptions. As with any test, normative values must be defined so imbalances can be isolated and progress can be moni- tored. The remainder of this article will review the criteria that Meyer has standardized in performing the back squat assessment. Follow-up articles will address imbalances and corrective principles. The unloaded Back Squat Assessment (BSA) is divided into three comprehen- sive domains: Upper Body, (head, neck and torso), Lower Body, (hips, knees and ankles), and Movement Mechanics, (timing, coordination and recruitment patterns). Each domain is graded for neuromuscular, strength and mobility deficits. The patient is assessed from the anterior, posterior and lateral perspectives and the test is performed for 10 repetitions. A positive finding is failure to perform the desired technique on two repetitions. Since the BSA is a functional assessment, it is performed when the patient is pain free. If the BSA provokes pain the test is discontinued until the underlying pain driver is addressed. Arm and hand position: •  Pronated grip on a dowel (metal, wood, plastic approximately 36” long) slightly greater than shoulder width •  Rest the dowel across the posterior deltoids just below C7. •  Forearms parallel to the torso and wrists straight •  “Bend the Bar” – pull the bar into the trapezius and tighten the scapular retractors, depressors and latissimus (essentially creating additional core stability) •  If a dowel is not available, the patient places hands open palmed under their ears while retracting their scapulae Stance: •  Heels approximately shoulder-width apart and toes pointing forward •  Maximum of 10 degree external rotation of the feet are allowed •  Heels and forefoot are kept on the ground Note: Meyer finds this moderate stance appropriate since research documents an excessively narrow stance may increase forward knee translation and heighten anterior shear forces and a wide stance may increase patellofemoral and tibiofemoral compressive forces in the knee joint by up to 15 percent during descent. Upper body: •  Head and neck in neutral alignment to slight extension, in line with the torso •  Gaze: slightly upward with a neutral head position •  Thorax: chest up, thoracic spine slightly extended and held rigid. Scapulae are retracted and depressed with the patient’s fore- arms parallel to the spine •  Lumbar spine and trunk: neutral alignment throughout the entire squat movement. From the lateral view, the line of the trunk is maintained parallel to the line of the tibias. Lower Body: •  Neutral pelvic tilt •  Hips: square and stable •  Femurs: symmetrical movement without internal or external rotation •  Knee, frontal plane: track over the toes, no medial or lateral displace- ment •  Knee sagittal plane: anterior transla- tion that is parallel to the trunk Once the BSA is performed, simple corrections start immediately to help isolate imbalances in movement from strength. The descent needs to be smooth and controlled with a 2:1 ratio to the assent, emphasizing the eccentric component of the exercise. Squat depth is determined by quality of the squat with the goal of achieving the femurs slightly past parallel to the ground, hips back, tibia parallel to the torso and feet entirely on the ground. Adequate squat depth is required to maximally engage the hamstrings and gluteal complex but cannot be sacrificed for poor execution. The Back Squat: A Functional Assessment and Training Exercise