When a person sees a motor vehicle collision (MVC) coming, the natural reaction is often to brace for impact. A driver may grip the steering wheel tightly, straighten the arms, tense the shoulders, press firmly into the floor, or contract muscles throughout the body. Although this response is instinctive, bracing can change how collision forces are transmitted through the muscles, joints, and extremities.

Key Insight:

Bracing before a motor vehicle collision changes the biomechanics of the body during impact. Depending on the direction and severity of the collision, body position, and structures involved, muscle tension and rigid positioning may contribute to certain patterns of musculoskeletal injury. However, bracing does not necessarily make every collision injury more severe.

A relaxed body and a strongly braced body respond differently to sudden acceleration and deceleration. When muscles are contracted before impact, joints may become temporarily more rigid. Forces from the collision can then be transmitted through the hands, wrists, elbows, shoulders, spine, hips, knees, and feet depending on how the person is positioned.

Drivers frequently brace by tightly gripping the steering wheel and extending their arms. During impact, forces can travel through the hands and wrists into the elbows and shoulders. This may contribute to sprains, strains, joint irritation, or other upper-extremity injuries. Pain may therefore develop in areas that did not directly strike the interior of the vehicle.

Bracing through the legs can create a similar mechanism. A driver who sees a collision coming may forcefully press the brake pedal or floorboard. With the muscles contracted and the leg relatively rigid, collision forces may be transmitted through the ankle, knee, hip, and pelvis. The exact injury pattern depends on factors such as joint position, direction of force, vehicle movement, and collision severity.

Muscle tension itself can also influence how the neck and spine respond to sudden movement. During a collision, rapid acceleration, deceleration, and rotation can place stress on muscles, ligaments, joints, and other tissues. Pre-impact muscle activation is one of several factors that can affect the biomechanics of the head, neck, and torso.

This is one reason the details surrounding an MVC are important during an examination. Knowing whether a person anticipated the collision, had both hands on the steering wheel, was pressing the brake, had their head turned, or was sitting in an unusual position can provide useful information about the forces that may have acted on the body.

Symptoms may not be limited to the neck and back. After an MVC, a person may experience shoulder, elbow, wrist, hip, knee, or ankle pain in addition to more typical neck pain, headaches, stiffness, and back discomfort. Some symptoms may also become more noticeable hours or days after the collision.

A comprehensive chiropractic examination can evaluate range of motion, joint function, muscle tenderness, strength, neurological findings, and the areas involved in the specific mechanism of injury. When fracture, significant ligament injury, neurological injury, or another condition requiring additional evaluation is suspected, diagnostic imaging or referral may be appropriate.

When conservative treatment is appropriate, chiropractic care may include joint mobilization or manipulation, soft tissue therapy, therapeutic exercise, mobility work, and progressive rehabilitation. Treatment should be based on the individual examination findings rather than simply the fact that the patient was involved in a collision.

If you remember bracing immediately before an MVC, tell the healthcare provider performing your examination. Details such as gripping the steering wheel, pushing against the brake pedal, turning your head, or extending an arm can help provide a more complete understanding of the mechanism of injury.

Were you recently involved in a motor vehicle collision? Contact our office today to schedule a comprehensive evaluation and discuss a personalized treatment and rehabilitation plan.

Contact Us:
Dr. Peter Britton, DC & Dr. Alyssa Lenox, DC
1111 N. Northgate Way
Seattle, WA 98133
Phone: 206-523-2225
Appointments can be made on our website: https://intouchwithhealthseattle.com/home

Sources:

• Siegmund GP, Sanderson DJ, Myers BS, Inglis JT. Awareness Affects the Response of Human Subjects Exposed to a Single Whiplash-Like Perturbation. Spine.

• Kumar S, Narayan Y, Amell T. Role of Awareness in Head-Neck Acceleration in Low Velocity Rear-End Impacts. Accident Analysis & Prevention.

• Yoganandan N, Pintar FA, Cusick JF. Biomechanical Analyses of Whiplash Injuries Using an Experimental Model. Accident Analysis & Prevention.

• Insurance Institute for Highway Safety. Rear-Impact Protection and Whiplash Prevention.