Not all bariatric clients are built the same. And when it comes to seating, how someone carries their weight is often more important than how much they weigh.
Two clients with the same body weight may have drastically different seating needs depending on where their mass is distributed — abdomen, thighs, glutes, or overall. Without recognising these body shape differences, a chair that fits “on paper” can end up being clinically unsafe, uncomfortable, or even harmful.
Why Shape Beats Size
Prescribing seating based on weight capacity alone overlooks the functional realities of posture, pressure, and movement. Instead, clinicians need to ask:
- How does this client sit in real life?
- Where is their centre of mass?
- Which body parts need support, relief, or room to move?
Let’s look at some of the most common body shapes seen in bariatric clients — and how each one impacts seating.
Key Bariatric Body Shapes and Clinical Considerations
🟠 Apple (Android) Shape
- Mass is central, in the belly and chest.
- Clients often have limited trunk flexion / limited ability to lean forward.
- This shifts the centre of gravity forward, which can affect balance and breathing.
- Tilt-in-space can improve support, while a more open seat-to-back angle reduces abdominal compression.
Configura Bariatric Chair - Tilt-in-space position
🔵Apple Ascites Shape
- Caused by fluid build-up in the abdomen (ascites), often from liver disease or heart failure.
- Clients may struggle to tolerate upright sitting due to pressure on the diaphragm.
- These clients often need deep tilt-in-space to aid respiration and offload pressure from the pelvis.
🟡 Apple Panniculus Shape
- Features a hanging abdominal pannus (apron of tissue) that drapes over the groin or thighs.
- Shifts the centre of mass downward and forward.
- Can cause leg abduction, reduce usable seat depth, and make transfers more difficult.
- Requires wide seat bases, strong leg rests, and forward tilt for assisted stand transfers.
Configura Bariatric Chair - Forward tilt position
🟠 Pear (Gynoid) Shape
- Weight is mostly around the hips and thighs.
- Clients often sit with abducted legs — thighs positioned wider than the seat width.
- May experience hip and knee strain, and risk of external rotation or poor leg alignment.
- Leg rest channels, wider bases, and lateral leg support can reduce discomfort and risk.
🔴 Bulbous Gluteal Shape
- Clients have large gluteal mass (rear tissue) that pushes the pelvis forward.
- This can lead to posterior pelvic tilt, loss of backrest contact, and sacral sitting.
- Custom backrests with removable filler or contouring are essential to restore trunk alignment.
Why Poor Shape Matching Increases Risk
When seating doesn't match shape:
- Sliding, posterior pelvic tilt and sacral sitting increase.
- Breathing becomes restricted, especially with central mass.
- Transfer safety declines, particularly if feet lose contact or the client struggles to lean forward.
- Pressure injury risk escalates, especially when soft tissue is compressed by tight seat widths.
That’s why measuring only the “bony landmarks” or relying on standard anthropometric data fails many bariatric clients.
(Side and back view of seated person showing pressure points and poor posture alignment)
The Role of Weight Fluctuation and Swelling
In addition to body shape, clinicians must consider whether body size and mass change over time:
- Does the client experience lymphoedema or fluid shifts?
- Are there behavioural factors, such as binge eating, that may cause rapid weight gain?
- Is their condition stable, or are they in an acute or declining phase?
In cases where shape and weight fluctuate, modular chairs offer critical flexibility. Adjustable seat depth, width, leg rest length, and backrest contouring allow clinicians to reconfigure the same chair as the client’s needs evolve, rather than starting over each time.
Clinical Questions to Ask
When prescribing for a bariatric client, always ask:
- Where is the client’s mass concentrated?
- How does this affect their seated posture and transfers?
- Is their weight or shape stable — or are changes expected?
- What seating features will support comfort now and in the future?
👉 Coming Next Week
In our final blog of this series, we’ll explore when — and when not — to use tilt-in-space and forward tilt in bariatric seating. We’ll look at common mistakes, clinical benefits, and how to match the right tilt to the right client.
📖 Want to go deeper now?
Download the Whitepaper:
A Clinical Guide to Bariatric Recliner Seating: Considering Body Shape, Weight and Tilt – by Enable Lifecare
