Product Description
The MOBB Seat Wedge Cushion is an angled foam seating wedge that raises the hips higher than the knees, tilting the pelvis forward so the lower spine returns to its naturally balanced “S” shape. It tapers from 4.5″ at the rear to 2.5″ at the front and is available in 16″ and 18″ widths.
Slumping in a chair is usually a geometry problem, not a willpower problem. When the seat is flat, the pelvis rolls backwards, the lumbar curve flattens and the shoulders round forward to compensate. A wedge fixes the cause rather than the symptom: by lifting the back of the seat 4.5″ and dropping the front to 2.5″, it rotates the pelvis into a neutral position and lets the lower back hold its natural curve without conscious effort.
That same forward tilt is why wedges are so commonly recommended after hip surgery. Keeping the hips higher than the knees helps maintain the hip angle many post-operative protocols call for, and it makes standing up appreciably easier because your weight starts further forward over your feet. The cushion works equally well on a dining chair, an office chair, a recliner or a wheelchair seat.
Key Features
Restores the Spine’s Natural “S” Curve By raising the hips above the knees the wedge rotates the pelvis forward, letting the lumbar spine hold its natural curve instead of flattening into a slump.
4.5″ to 2.5″ Graduated Taper The slope is gentle enough to sit on all day but steep enough to change pelvic position meaningfully — a 2″ drop across the depth of the seat.
Recommended After Hip Surgery Keeping the hips higher than the knees supports the hip angle many post-operative protocols require, and shifts your weight forward to make standing easier.
Two Widths: 16″ and 18″ Choose 16″ for a standard chair or a narrower wheelchair seat, 18″ for a wider chair or a broader build. Both share the same 4.5″–2.5″ taper.
Works on Any Seat Dining chairs, office chairs, recliners, car seats and wheelchairs. Nothing to fit or fasten — the wedge simply sits on the existing seat.
Lifetime Limited Warranty Backed by MOBB Home Health Care’s lifetime limited warranty against manufacturing defects.
Choosing Between the 16″ and 18″
Measure the seat you will use it on most. The 16″ (16″L × 16″W) suits a standard dining or office chair and most 16″ wheelchair seats. The 18″ (18″L × 18″W) suits wider armchairs, recliners and 18″ wheelchairs, and gives a broader base of support for a larger build. When in doubt, match the width to the seat rather than to the person — a wedge wider than the chair will rock.
If your main problem is tailbone pain rather than posture, the Convertible Coccyx Cushion or Convertible Coccyx Wedge may suit you better, since both offer a removable coccyx cut-out that relieves direct pressure on the tailbone. The Seat Wedge Cushion is the right choice when the goal is pelvic position and posture.
Specifications
| Specification |
Details |
| Dimensions |
16″: 16"L x 16"W x 4.5"-2.5"H | 18″: 18"L x 18"W x 4.5"-2.5"H |
| Warranty |
Lifetime Limited Warranty |
| Available Options |
16″ (MHWWC) | 18″ (MHWWC18) |
| Brand |
MOBB Home Health Care |
Best For
- People who slump or slide forward in a chair and want the seat geometry corrected rather than having to hold themselves upright
- Patients recovering from hip surgery who need the hips kept higher than the knees
- Wheelchair and armchair users who find standing up difficult, since the forward tilt shifts weight over the feet
- Anyone with lower back fatigue from long periods of seated work, driving or television watching
Why Choose This Product
- Addresses the cause of slumping — a flat seat — rather than asking the user to correct their posture by effort
- A genuine 2″ taper across the seat depth, enough to change pelvic position rather than simply adding padding
- Backed by MOBB’s lifetime limited warranty and stocked in Canada by Factory Direct Medical for fast domestic shipping
Frequently Asked Questions
Which way round does a seat wedge cushion go?
The thick edge (4.5″) goes at the back of the chair and the thin edge (2.5″) at the front, so your hips sit higher than your knees. Placing it the other way round tilts the pelvis backwards and makes slumping worse. If the cushion has a shaped or contoured face, that side goes up.
Is a wedge cushion good for lower back pain?
It helps the kind of back pain caused by seated posture. By tilting the pelvis forward it restores the lumbar curve, which reduces the sustained stretch on the ligaments and discs of the lower back that flat seating creates. It will not treat back pain from disc herniation, stenosis or arthritis — those need clinical assessment. If pain increases while using it, stop and speak to a physiotherapist.
Can I use this cushion after hip replacement surgery?
It is commonly used for exactly that. Many hip protocols ask you to avoid bending the hip past 90 degrees, and raising the hips above the knees helps keep the joint within that range while seated. Confirm with your surgeon or occupational therapist first, as protocols differ between procedures and surgeons.
What is the difference between a wedge cushion and a coccyx cushion?
A wedge changes the angle of the seat to reposition the pelvis and is aimed at posture. A coccyx cushion has a cut-out at the rear that removes direct pressure from the tailbone and is aimed at tailbone pain. MOBB’s Convertible Coccyx Wedge combines both — a full wedge with a removable coccyx cut-out attached by Velcro.
Summary
The MOBB Seat Wedge Cushion is an angled foam seating wedge tapering from 4.5″ to 2.5″ that raises the hips above the knees to restore the spine’s natural curve. Available in 16″ and 18″ widths with a lifetime limited warranty, from Factory Direct Medical.
Important Notice: This product is a comfort and positioning aid and is not a substitute for professional medical advice, diagnosis or treatment. If you are managing pressure injuries, post-surgical recovery or a diagnosed spinal condition, consult an occupational therapist or physiotherapist before use to confirm it is appropriate for you. Discontinue use and seek advice if you experience increased pain, numbness or skin redness.
