Spinal Motion Restriction (SMR)

SMR limits unwanted spine movement after blunt trauma when a trigger is present. Apply it selectively, and keep the whole spine aligned during every move.

Spinal motion restriction (SMR) means a cervical collar and a supporting device, used to limit unwanted movement of a spine that may be injured. SMR reduces movement. It does not truly immobilize the spine. That is why the 2018 joint statement of the American College of Surgeons Committee on Trauma (ACS-COT), the American College of Emergency Physicians (ACEP) and the National Association of EMS Physicians (NAEMSP) prefers the term SMR.

How It Works

• Collar: a properly sized cervical collar limits neck movement. It is a critical part of SMR, not an optional extra.
• Whole-spine alignment: keep head, neck and torso in line. SMR covers the entire spine, not only the neck.
• Supporting device: a long backboard, scoop stretcher, vacuum mattress or ambulance cot. Secure the patient to it safely.
• Controlled transfers: moves on a board, scoop or vacuum mattress cut down flexion, extension and rotation.
• Selective use: triggers decide. SMR is not for every trauma patient.

Where It Fits

Prehospital SMR indications after blunt trauma come from the 2018 joint statement. The NEXUS criteria and the Canadian C-spine rule ask a different question, namely whether an alert adult needs cervical imaging in the ED. They were built for that decision, never as EMS SMR criteria. The PECARN prediction rule plays the same imaging role for children.

Canadian C-spine rule (alert, stable adults with blunt trauma, GCS 15): a single high-risk factor sends the patient to imaging. The high-risk factors are age 65 or older, a dangerous mechanism and paresthesias. A dangerous mechanism is a fall from more than 3 ft (91 cm) or five stairs, an axial load to the head, a motor vehicle collision above 100 km/h, rollover or ejection, a motorized recreational vehicle, and a bicycle collision. If none of those apply, check for a low-risk factor: a simple rear-end collision, sitting in the ED, ambulatory since injury, delayed onset of neck pain or no midline tenderness. A low-risk factor allows an active rotation test. Rotating 45 degrees to each side means no imaging. Otherwise, image.

Indications

• Altered level of consciousness: GCS <15 or evidence of intoxication
• Midline neck or back pain or tenderness
• Focal neurologic signs or symptoms: numbness or motor weakness
• Anatomic deformity of the spine
• Distracting circumstances or injury: long bone fracture, degloving or crush injury, large burns, emotional distress, communication barrier, or any similar injury that prevents a reliable exam

Absolute Contraindications

• Penetrating trauma: SMR has no role here. The 2018 joint statement says so without exception (point 9). The EAST 2018 guideline recommends against routine immobilization in penetrating trauma.

The statement's blunt-trauma indications do not cover mixed penetrating and blunt mechanisms. Follow local protocol.

Relative Contraindications & Cautions

• Sitting position: SMR cannot be done properly while the patient sits. Plan the move to supine (see Alternative Technique).
• Prolonged time on a hard surface: raises the risk of pain and pressure injury. Reach for a vacuum mattress or padding, and keep time on the board short.
• Young children: a communication barrier alone does not mandate SMR. Apply the pediatric criteria in Special Populations.

Consider an Alternative

Point 4, after blunt trauma, is the basis for SMR in the joint statement. An alert, examinable adult with none of those triggers does not meet its indications. The statement does not name ambulatory patients, so a walking patient without a trigger is assessed under local protocol, not put on a board by default. The ED decides whether to image, under local protocol, using the NEXUS or Canadian C-spine rule.

Abort / Stop Criteria

Stop the transfer, re-align and re-check when motor, sensory or pain status changes during a move.

Team Roles During the Procedure

• Spine lead: holds the head and calls each move.
• Collar and device: applies the collar and checks fit and straps.
• Airway and oxygen: keeps the airway protected through every move.
• Monitor and recorder: performs and records the neurologic exam before and after moves.
• Safety call: announces each move and confirms that the head and torso stay aligned.

Equipment

Sizing

The manufacturer's chart matches collar size to the patient's neck. Device weight limits come from the manufacturer's instructions. This page gives no numeric size chart.

Patient Positioning & Preparation

Lay the patient supine, with the head neutral and the torso aligned. Do not attempt SMR on a sitting patient. In young children, plan the shoulder padding before the head goes on the device.

Phase 1: Prepare

1. Confirm the trigger: check the five indications. Age alone is not a trigger.
2. Gather the equipment: collar of the correct size, device, straps and padding.
3. Stabilize the head: hold the head and neck in line with the torso until the collar is on and the athlete is secured to the device. A rigid collar does not limit motion in every plane, so keep manual in-line stabilization until the device is secured.

Phase 2: Perform

4. Apply the collar: use an appropriately sized collar and check fit.
5. Position on the device: keep the head, neck and torso aligned. If the head must be raised, elevate the device at the head while keeping the neck and torso aligned.
6. Transfer: use a log roll with a long board, scoop stretcher or vacuum mattress. Minimize flexion, extension and rotation.

7. Secure to the device: fasten straps across chest, pelvis and head. Confirm the collar is still in place.
8. Pad in children: add padding under the shoulders of young children so the neck is neutral.
9. Move to the cot: remove extrication devices on the cot only with enough trained staff to avoid unnecessary movement. For a short transport, it may be better to transport on the device and remove it on arrival.

Phase 3: Confirm & Secure

10. Re-check neurologic status: document motor, sensation and pain before and after each move. See Confirmation & Monitoring.
11. Re-check alignment: confirm the collar fits, the straps are secure and the head and torso are aligned.
12. Hand over at arrival: remove from the device promptly with a slider board or enough staff, keeping SMR during every move.

Alternative Technique: Seated Patient

A sitting patient cannot be placed in SMR. If extrication is needed, use a seated extrication device per protocol to move the patient. Transition to a supine device at the earliest safe point, then re-check the neurologic exam before and after the transition.

Primary Confirmation

Before and after the move, the neurologic exam is documented and shows no new deficit. The collar is on, fitted and secure, and the head and torso are aligned on the device.

Secondary Confirmation

• Collar fits without gaps and does not move
• Head and torso aligned on the device
• Straps secure and fastened to the device
• No new pressure points at the occiput, shoulders, scapulae or sacrum

Ongoing Monitoring

• Neurologic status: before and after every move and at each reassessment
• Pain and skin: at each reassessment, per protocol
• Mental status: changes that alter the exam, including intoxication
• Collar and alignment: after each move and on hospital transfer

Pediatrics

Prehospital spinal decisions should not hinge on age alone. In young children, a communication barrier does not on its own call for SMR. The joint statement recommends a collar when a child has any of the following:

• Neck pain
• Torticollis
• Neurologic deficit
• Altered mental status: GCS <15, intoxication, or other signs such as agitation, apnea, hypopnea or somnolence
• High-risk motor vehicle collision, high-impact diving injury, or substantial torso injury

Young children need extra padding under the shoulders, so the neck stays clear of excessive flexion. Time on a board should be short. If it runs long, use a vacuum mattress or padding. Pediatric collar sizing and weight-based equipment are covered on the pediatric pages linked below.

In a PECARN EMS cohort of 7,721 children with blunt trauma, SMR was placed in 41.5%. Only 1.6% had a cervical spine injury. Those two figures show how often SMR is applied in children.

Equipment sizing · Pediatric airway

Older Adults

Age 65 or older is a high-risk factor in the Canadian C-spine rule, and it mandates imaging in the ED. EMS does not use age on its own to mandate SMR. The trigger list still applies.

Fixed deformity (protocol-dependent teaching): kyphosis or a fixed spinal deformity, such as ankylosing spondylitis, may stop the spine from reaching neutral. Pad to the position found, and never force the spine straight. This is standard teaching, not part of the 2018 joint statement. Check it against local protocol.

Intoxicated or Distracting Injury

• Intoxication and altered mental status are SMR triggers. With the exam unreliable, keep SMR on until the exam can be trusted or imaging decides.
• If clinical reliability is compromised, multidetector CT is the primary screening tool in the 2026 clearance review.
• A distracting injury (long bone fracture, large burn) is a trigger on its own.

Pregnancy (protocol-dependent teaching)

Late in pregnancy, lying supine can compress the aorta and vena cava. Tilt the device to the left, or push the uterus aside by hand, per protocol. This is standard teaching, not from the 2018 joint statement. Check it against local protocol and current ATLS or PHTLS.

Bariatric Patients (protocol-dependent teaching)

Start by checking the device weight limit. Every move needs extra trained staff and equipment, so plan for them. Verify the collar size and padding against local protocol.

Helmet and Shoulder Pads (athletes)

The current consensus comes from the 2020 Spine Injury in Sport Group statement on prehospital care of the spine-injured tackle football athlete. It treats the helmet and shoulder pads as one unit:

• Airway, circulation and breathing first: they come before equipment removal. Onsite medical personnel decide whether to remove equipment before transport, based on the athlete's status, the equipment worn, the number of rescuers and their training.
• Face mask: removing the face mask on the field, with immediate transport, is still reasonable. If the mask cannot come off in a timely way, the helmet may need to come off to reach the airway during respiratory distress or arrest.
• Helmet and shoulder pads together: if equipment comes off before transport, take both off together when possible. The helmet comes off first, then the shoulder pads.
• Helmet only: if the helmet comes off and the shoulder pads stay on, pad the space under the head to prevent cervical extension.
• Technique: hold manual in-line stabilization throughout removal. Cut the jersey and the front of the shoulder pads to expose the chest. Depending on the technique, removal takes 2 to 9 trained rescuers. Practice under supervision.

Removal matters because shoulder pads can block chest compressions and access to the defibrillator. Follow the agency protocol.

Immediate Aftercare

• Re-check neurologic status, collar and alignment on arrival, after each transfer and on the stretcher.
• Keep SMR until a clinician clears the spine or removes it per protocol.

Ongoing Maintenance

• Check collar fit and skin at each reassessment.
• Reposition padding and relieve pressure points.
• Reassess pain and treat per protocol.

Transport Considerations

• Short transport: keep the patient on the device and remove it on arrival, as the joint statement describes.
• Longer transport: take extrication devices off on the cot, and only with enough trained staff.
• Vehicle motion: secure the device to the cot and re-check after bumps and turns.
• Hospital transfer: a high-risk move. Use a slider board or enough staff to keep alignment.
• Noise and vibration: the patient's words alone are not enough. Lean on the neurologic exam and monitors.

Pearls

• Selective, not routine: one trigger is enough. No trigger, no SMR under the joint statement.
• Whole spine: think beyond the neck. SMR covers the entire spine.
• Age is not a trigger: for children, use the collar criteria.
• Plan the sitting patient: SMR cannot be done sitting. Plan the supine transition early.
• Document the neuro exam: chart it before and after every move.

Common Pitfalls

• Collar used as clearance: keep SMR on until someone makes the clearance decision.
• Routine board for every fall: triggers decide. Keep time on the board short.
• Sitting patient moved flat without a plan: use a seated device per protocol, then move to supine.
• SMR for penetrating trauma: SMR has no role in penetrating trauma.
• No padding for a child: pad under the shoulders so the neck stays neutral.

Skill Maintenance

• Practice log roll and board or scoop transfers in simulation at least each refresher cycle.
• Drill collar sizing on adult and pediatric manikins.
• Rehearse the neurologic exam before and after moves, and document it.
• Debrief after each transfer drill: alignment, calls, and exam timing.
• Check the agency's device inventory and straps at each shift.