Where is the majority of flexion, extension, and rotation located in the cervical spine?

Cervical Spine Motion Distribution

The majority of flexion and extension occurs at the mid-to-lower cervical spine (C4-C7), while the majority of rotation occurs at the atlantoaxial joint (C1-C2), which accounts for approximately 50% of total cervical rotation. 1

Rotation Distribution

• The C1-C2 joint is the primary site of cervical rotation, contributing 38.9 degrees per side with a range of motion that represents the greatest intervertebral motion in the entire spine 1
• The neutral zone at C1-C2 constitutes 75% of the total rotational motion at this level, indicating substantial rotational capacity 1
• The subaxial cervical spine (C2-C7) combined provides approximately the same amount of rotation as C1-C2 alone, making the atlantoaxial joint responsible for roughly half of total cervical rotation 1

Flexion and Extension Distribution

• Flexion and extension are distributed throughout the cervical spine with increasing contributions from lower segments as range of motion progresses 2
• The occiput-C1 joint contributes 3.5 degrees of flexion and 21.0 degrees of extension 1
• The C1-C2 joint provides 11.5 degrees of flexion and 10.9 degrees of extension 1
• Lower cervical spine segments (C4-C7) progressively increase their contributions to head motion near the end range of flexion and extension, meaning these segments bear greater loads at terminal positions 2

Flexion-Specific Patterns

• Full-length cervical flexion produces more flexion at lower segments compared to protraction movements 3
• During flexion, the upper cervical segments (occiput-C2) are positioned in their flexion range, but only retraction movements take these segments to their full end-range flexion 3

Extension-Specific Patterns

• Full-length cervical extension produces more extension at lower segments compared to retraction movements 3
• During extension, upper cervical segments are positioned in their extension range, but only protraction movements take occiput-C1 and C1-C2 to their full end-range extension 3

Lateral Bending Distribution

• The occiput-C1 joint contributes 5.5 degrees of lateral bending per side 1
• The C1-C2 joint provides 6.7 degrees of lateral bending per side 1
• Lateral bending is moderately distributed throughout the cervical spine with relatively equal contributions from upper and lower segments 4

Clinical Implications

• Patients should be advised to avoid end-range positions during activities, as inferior motion segments experience increased demand and loading at terminal ranges of motion 2
• The asymmetric distribution of motion explains why different cervical pathologies affect different levels—rotational injuries predominantly affect C1-C2, while flexion-extension injuries more commonly involve the lower cervical spine 2, 1
• Improved cervical lordosis is associated with significant improvement in translational and rotational motions of the lower cervical spine, indicating that sagittal alignment affects segmental kinematics 5