Safe Patient Handling, Ergonomics & Transfers

Safe Patient Handling, Ergonomics & Transfers

Biomechanical Foundations & Ergonomics for the Imaging Assistant

Safe patient handling depends on the fundamental laws of classical physics and biomechanics. The human musculoskeletal system acts as a system of levers, with the spine functioning as a flexible column subject to severe compressive and shear forces during manual lifting.

The Three Core Biomechanical Principles

1. Broad Base of Support: The stability of any object depends on the size of its base of support. An assistant must position their feet shoulder-width apart, placing one foot slightly forward in the direction of intended movement. This provides multidirectional stability across both sagittal and coronal planes, preventing loss of balance during unexpected patient weight shifts.
2. Center of Gravity (COG) Alignment: In an upright human, the center of gravity is situated centrally in the pelvis at approximately the level of the second sacral vertebra (S2). To maintain balance, the body's line of gravity must fall directly within the base of support. When lifting or transferring a patient, the assistant must lower their own COG by flexing the hips and knees, bringing the patient's body as close to their own torso as possible. Holding a load away from the body dramatically lengthens the external resistance arm, multiplying the compressive force exerted on the L4–L5 and L5–S1 intervertebral discs.
3. Large Muscle Group Recruitment: The extensor muscles of the lower spine (erector spinae) are relatively small and designed for postural stabilization, not heavy lifting. Assistants must keep the lumbar spine in its neutral lordotic alignment, bend at the knees and hips, and engage the massive muscle groups of the lower extremities—namely the quadriceps, gluteals, and hamstrings—along with the core abdominal musculature.

Pushing vs. Pulling vs. Lifting

Whenever possible, assistants should push, pull, or roll rather than lift. Pushing allows the assistant to lean their body weight into the load and recruit chest and quadriceps power. When transferring patients laterally, pulling using body weight shifting is mechanically superior to lifting vertically against gravity.

Comprehensive Pre-Transfer Assessment & Tubing Protocol

Prior to initiating any patient move, the Imaging Assistant must conduct a systematic clinical assessment of the patient's physical and cognitive status.

Assessing Mobility and Orthostatic Risk

• Weight-Bearing Capacity: Determine whether the patient is full weight-bearing, partial weight-bearing, or non-weight-bearing. Inquire whether the patient has unilateral weakness (hemiparesis) resulting from a cerebrovascular accident (stroke) or orthopedic injury.
• Cognitive Cooperation: Verify that the patient can understand and follow simple, sequential instructions.
• Orthostatic Hypotension Prevention: Patients who have been recumbent or bedridden for extended periods suffer from blunted baroreceptor reflexes. Upon sitting or standing upright, gravitational blood pooling in the lower extremities causes a sudden drop in cerebral blood flow, manifesting as dizziness, lightheadedness, pallor, cold diaphoresis, and sudden syncope.
  • Clinical Prevention: When clinically permitted, transition the bedridden patient into a seated position with feet dangling over the edge of the bed or stretcher for 1 to 2 minutes. Converse with the patient and observe their facial color and alertness before assisting them to a standing position.

Managing Lines, Catheters, and Drainage Systems

• Intravenous (IV) Lines: Ensure there is adequate tubing slack so lines do not pull or dislodge during transfers. Never permit tension on an IV cannulation site. Confirm that any IV infusion pole entering the suite is certified MR Conditional.
• Urinary Foley Catheters: The urinary collection bag must always be maintained below the level of the patient's bladder. Elevating the bag above bladder level creates retrograde flow of stagnant urine back through the catheter, introducing pathogens into the urinary tract and causing catheter-associated urinary tract infections (CAUTIs). Never place a Foley bag on the patient's abdomen, chest, or table surface above the pelvis.
• Chest Tubes and Surgical Drains: Keep drainage canisters upright and positioned below the level of the patient's chest or wound insertion site to maintain continuous gravity drainage and prevent backflow of serosanguineous fluids.

Wheelchair Transfers: Standing Pivot Technique

The standing pivot transfer is utilized for patients who can bear weight on at least one lower extremity and are cooperative.

Setup and Positioning

1. Wheelchair Orientation: Position the wheelchair at a 45-degree angle to the MRI table or transfer surface. Orient the chair so the patient's stronger (unaffected) side is closest to the destination table, allowing them to pivot onto their stable leg.
2. Wheelchair Locks: Engage the mechanical wheel locks on both sides of the wheelchair. Verify that the chair cannot roll or rotate.
3. Footrests: Fold up both footplates and swing the leg rests completely outward to the sides, or detach them entirely. Leaving footrests in place presents a severe tripping hazard for both patient and staff.
4. Gait Belt Application: Apply a sturdy fabric transfer/gait belt snugly around the patient's waist over their clothing (leaving space for two flat fingers beneath the belt). Never grasp a patient by their clothing, belt loops, or axillae. Pulling on the patient's arms or axillae can stretch the brachial plexus or dislocate the glenohumeral joint.

Execution of the Standing Pivot

1. Instruct the patient to slide forward toward the front edge of the wheelchair seat, placing their feet flat on the floor.
2. The assistant assumes a wide stance, placing their feet outside the patient's feet, and braces their outer knee and foot against the patient's weaker leg to prevent sudden knee buckling.
3. The assistant grasps the gait belt on both sides using an underhand (supinated) grip, keeping their back straight and elbows close to the torso.
4. Instruct the patient to lean forward (bringing their "nose over toes") and place their hands on the wheelchair armrests to push upward.
5. On a synchronized count of three ("1, 2, 3, stand"), the patient pushes off the armrests while the assistant shifts their body weight backward, using their legs to guide the patient into a fully upright stand.
6. Pause briefly to assess the patient's balance and ensure they are not experiencing orthostatic dizziness.
7. Instruct the patient to take small steps, pivoting on their stronger foot until their back is aligned with the scanner table.
8. The patient steps backward until they feel the edge of the table against the back of their calves.
9. The patient reaches back with both hands to grasp the table surface, and the assistant bends their knees to smoothly guide the patient down into a seated position.