Strain, quadratus lumborum muscle

• Low back pain
• Mechanical low back pain
• Lumbar sprain

• 724.2 Lumbago
• 847.2 Lumbar sprain

• M54.5 Low back pain
• S33.5 Sprain of ligaments of lumbar spine

• Pattern 4F: Impaired Joint Mobility, Motor Function, Muscle Performance, Range of Motion, and Reflex Integrity Associated With Spinal Disorders

Description

• Quadratus lumborum muscle runs from the posterior superior iliac crest to the 12th rib
• Can be unilateral or bilateral depending on mechanism of injury
• Tenderness along origin, insertion, and line of muscle
• Pain over muscle that radiates with trigger point pattern
• May cause respiratory issues due to insertion of the muscle on the 12th rib
• Most episodes are self-limiting

Essentials of Diagnosis

• Diagnosis made by clinical examination
• Use of treatment- or impairment-based classification system is useful to determine evidence-based treatment plan
• Reproduction of symptoms in specific postures and activities
• Rule out systemic disease (red and yellow flags)

General Considerations

• Presentation may vary significantly based on anatomical structures and psychosocial factors
• Often difficult to determine patho-anatomical cause of pain
• Poor spinal alignment, scoliosis, and 12th-rib dysfunction can cause irritation of muscle by altering the length-tension ratio

Demographics

• Variable based on specific condition
• May be specific to athletes, younger populations prone to extreme spinal movements

Signs and Symptoms

• Pain lateral to lumbar spine between 12th rib and iliac crest that can be mechanically reproduced
• Unilateral or bilateral pain along length of muscle or attachment
• Lumbar segmental and 12th-rib hypomobility
• Respiratory limitations
• Difficulty with lumbar spine ROM
• Often associated with poor body mechanics, core-muscle weakness, and postural deviations

Functional Implications

• May be a leading cause of occupational disability
• May impede ability to perform ADLs/IADLs
• May impede participation in sports and other social activities

Possible Contributing Causes

• Occupational factors
• Congenital anomalies
• Physical condition
• Smoking
• Obesity
• Socio-economic factors
• Psychosocial and behavioral factors
• Postural changes
• Weakness of core musculature
• Tightness of hip flexors, external rotators, hamstrings

Differential Diagnosis

• Facet joint dysfunction
• Malignant spinal tumor or metastasis
• Referred pain from visceral structures
• Systemic auto-immune disease (rheumatoid arthritis, Reiter's syndrome)
• Spondylosis
• Spondylitis
• Spondylolisthesis
• Spinal misalignment
• Sacral dysfunction
• Erector spinae muscle strain
• Myofascial pain syndrome
• Herniated disc
• 12th-rib fracture
• 12th-rib dysfunction
• Scoliosis
• Respiratory problems
• Leg-length discrepancy

Imaging

• Not necessary in most cases; only with persistent symptoms not responding to conservative management or if red/yellow flags are present
• MRI helpful in diagnosis to visualize structure of muscle, compressed or inflamed nerve root, or disc pathology
• X-ray/plain-film radiograph helps to assess alignment, fractures, stability (flexion/extension radiograph)
• CT to ...