ASN Osteopathic Structural Exam Assessment of Symmetry Asymmetry 2025 - Tagged

Symmetry refers to the balanced and equal alignment of body structures on both sides of the body, while asymmetry indicates a deviation or imbalance. In osteopathic structural examination, identifying symmetry versus asymmetry helps detect visible defects, functional deficits, and abnormalities of alignment, which may be related to the patient's symptoms or underlying pathology. Recognizing these differences is crucial for diagnosing somatic dysfunction and planning appropriate treatment. p.3-10

• Caudad: toward the feet (inferior)
• Cephalad: toward the head (superior)
• Anterior: toward the front (ventral)
• Posterior: toward the back (dorsal)
• Medial: toward the midline
• Lateral: toward the outside
• Proximal: toward the center of the body or nearest the point of attachment
• Distal: away from the center of the body or away from the point of attachment

To determine your dominant eye, form a triangle with your hands and focus on a distant object through the opening with both eyes open. Close one eye at a time; the eye that keeps the object centered is your dominant eye. This is important in the osteopathic structural exam because using your dominant eye ensures accurate midline assessment and comparison of anatomical structures, reducing parallax error.

The recommended sequence involves observing static landmarks in the posterior, anterior, and lateral planes/views of the body. Observations should be made from inferior to superior and lateral to medial directions, comparing each body area bilaterally and noting general contour, unnatural positions, use of extremities, muscle tone, and truncal positions. p.10, 15

The static musculoskeletal exam assesses:

• Anatomic aspects: alignment and position of bones, joints, and soft tissues
• Postural aspects: overall posture, spinal curves, and balance
• Biomechanical aspects: how structure affects function, including compensations and movement patterns Key findings include asymmetry, restricted motion, tissue texture changes, and tenderness (ARTT). p.9-10

Observing static asymmetries can indicate underlying somatic dysfunction, which may contribute to pain, impaired function, or compensatory changes elsewhere in the body. Recognizing these asymmetries helps guide diagnosis and treatment, as structural changes often lead to functional changes, especially at transition zones that are susceptible to biomechanical stress. p.9, 13

At birth, the spine has one large kyphotic curve. As the cervical extensor muscles develop and the head is raised, a cervical lordotic curve forms. As the infant begins to crawl and walk, the lumbar lordotic curve develops.

Primary curves are kyphotic (posterior convexity, anterior concavity) and are present in the thoracic and sacral regions. Secondary curves are lordotic (posterior concavity, anterior convexity) and develop in the cervical and lumbar regions after birth.

Transition zones are anatomically defined areas where the structure of the spine changes, such as the occipitocervical, cervicothoracic, thoracolumbar, and lumbopelvic junctions (OA, C7-T1, T12-L1, L5-S1). These areas are commonly susceptible to somatic dysfunction and biomechanical stress.

Foot pronation (pes planus) is characterized by the foot pointing inward with an outward tilt of the heel, resulting in a flat or low arch. Foot supination (pes cavus) is characterized by a high arch and an inward tilt of the heel. p.34-35

Genu valgum is also known as 'knock-knee,' where the knees angle inward and touch each other when the legs are straightened. Genu varum is 'bow-legged,' where the knees stay apart when the ankles are together.

Clinical features include the patient's torso/trunk being forward bent and side bent to the left, left iliac crest elevated with pelvic shift to the right, and the left lower extremity externally rotated/everted.

Medial winging is due to weakness of the serratus anterior muscle from injury to the long thoracic nerve (C5, C6, C7 nerve root/Brachial Plexus). Lateral winging is due to trapezius and rhomboid weakness or paralysis.

Pectus excavatum is a 'funnel chest,' where the chest is sunken inwards. Pectus carinatum is 'pigeon breast,' where the sternum protrudes outward. p.39-40

Genu recurvatum is hyperextension of the knees, commonly seen in gymnasts.