SMS Postural Support and Positioning 2 — Questions and Answers
Question 1: What is the 90-90-90 rule in seating?
- 90% weight through ischials, 90-degree knees, 90-degree ankles
- Hips, knees, and ankles each at 90-degree angles (Correct answer)
- Seat tilt of 90 degrees, back angle of 90 degrees, footrest at 90 degrees
- 90 minutes maximum seated time
Correct answer: Hips, knees, and ankles each at 90-degree angles
The 90-90-90 rule describes ideal seated alignment with hips, knees, and ankles each at approximately 90 degrees.
Question 2: A simulator is used during the seating evaluation primarily to:
- Determine insurance reimbursement eligibility
- Assess positioning tolerance and simulate equipment configurations before ordering (Correct answer)
- Train caregivers on transfers
- Measure spasticity levels
Correct answer: Assess positioning tolerance and simulate equipment configurations before ordering
A seating simulator allows the clinician to trial different angles and support configurations to determine optimal positioning before ordering custom equipment.
Question 3: Which muscle group tightness most commonly contributes to anterior pelvic tilt in sitting?
- Hamstrings
- Hip flexors (Correct answer)
- Hip abductors
- Plantarflexors
Correct answer: Hip flexors
Tight hip flexors pull the pelvis anteriorly, causing anterior pelvic tilt and excessive lumbar lordosis.
Question 4: Pelvic obliquity in sitting is best described as:
- Forward tilting of the pelvis
- One side of the pelvis higher than the other (Correct answer)
- Backward rotation of both iliac crests
- Excessive lateral hip rotation
Correct answer: One side of the pelvis higher than the other
Pelvic obliquity is a lateral tilt of the pelvis where one iliac crest is higher than the other in the frontal plane.
Question 5: When assessing a client's sitting balance, the SMS clinician should first evaluate:
- Wheelchair model preferences
- Supported and unsupported sitting ability (Correct answer)
- Insurance funding source
- Home environment accessibility
Correct answer: Supported and unsupported sitting ability
Evaluating both supported and unsupported sitting balance determines the level of external postural support required from the seating system.
Question 6: Which term describes a pelvis that has rotated forward so one side is more anterior than the other in the horizontal plane?
- Pelvic obliquity
- Pelvic rotation (Correct answer)
- Anterior pelvic tilt
- Posterior pelvic tilt
Correct answer: Pelvic rotation
Pelvic rotation refers to horizontal plane rotation where one iliac crest is more anterior than the other.
SMS Postural Support and Positioning 2
What is the 90-90-90 rule in seating?