april 2025
OFFICE CHAIR CUSHION PERFORMANCE TESTING
Department of Rehabilitation Science and Technology
School of Health and Rehabilitation Sciences
University of Pittsburgh
The University of Pittsburgh School of Health and Rehabilitation Sciences conducted standardized bench testing on 11 leading office chairs, using pressure mapping technology to measure Peak Pressure Index—the most relevant comfort metric for the average office worker who sits 8+ hours a day.
PRESSURE MAPPING ISO 16840-6
Peak pressure index:
why it matters
Peak pressure refers to concentrated force under the sit bones (ischial tuberosities). Higher values (in red) can cause discomfort, while lower values (in blue) mean better pressure distribution and more comfort during long seated hours. Pitt’s test used a rigid load indenter to ensure repeatable and unbiased results.
*Performed April 5, 2025 using ISO 16840-6 methodology with a rigid load indenter.
ANTHROS CHAIR
SECRETLAB TITAN™
HERMAN MILLER® EMBODY
HERMAN MILLER® AERON
PITTSBURGH RESULTS
(Cushion Only Testing)
Peak Pressure Index—Lower is Better
LESS
0 mmHg
MORE
200 mmHg
i Limitations of Rigid Testing
While helpful for measuring cushion mechanics, rigid load testing doesn't reflect how real people move, shift, or react to sitting. It lacks soft tissue variation, muscle activity, and real-life posture changes. That’s why human testing is essential to complete the story.
*Performed on 4/5/25 at the University of Pittsburgh with a rigid load indenter. Human results may vary.
aUGUST 2025
HUMAN-BASED PRESSURE TESTING
Jack P. Callaghan PhD, FCSB, FCAHS, CCPE
Professor and Canada Research Chair in Spine Biomechanics and Injury Prevention
Department of Kinesiology and Health Sciences, Faculty of Health University of Waterloo
To evaluate how chairs perform with actual people, researchers at the University of Waterloo conducted a comprehensive biomechanical study comparing the Anthros chair to the Herman Miller x Logitech Embody. This study measured seat pressure, during real seated computer work.
WHAT THEY TESTED
16 participants (equal number of men and women) completed one hour of work in each chair, seated on a pressure map to measure peak pressures.
SEAT PAN PRESSURE FINDINGS (REAL HUMANS)
- 36 mmHg lower peak pressure in Anthros vs. Embody
- Smaller total pressure, and with better pressure dispersion, especially in men
- Participants sat slightly more upright in Anthros, helping with upright posture
Key Takeaway
Even with smaller contact area, Anthros delivered better comfort and lower pressure due to smart cushion design and posture alignment.
FINAL TAKEAWAY
Anthros achieved the lowest peak pressure in independent university lab testing, demonstrating measurable pressure relief for real people in real time.
posture testing:
the precision posture system
Built on Biomechanics. Proven by Research.
Prolonged sitting is one of the biggest contributors to spinal compression, disc stress, and posture-related pain. The adjustable two-part back system was designed to solve that problem — not with a one-size-fits-all lumbar pad, but with precision postural control that adapts to every body type.
Backed by independent university research and validated digital human modeling, this system supports the spine where it matters most, at the pelvis and thoracic segments, helping maintain a neutral posture, reduce disc pressure, and prevent long-term strain.
Keeping the Spine Safe Zone
The lumbar spine’s two most mobile joints, L4–L5 and L5–S1, are where most flexion and loading occur when sitting. Both Pope et al. (1986) and White & Panjabi (1990) quantified segmental lumbar ranges of motion in healthy adults.
Their data, which have become the accepted clinical and research reference values, report approximately:
| SEGMENT | FLEXION ROM |
| L4–L5 | 12–15° |
| L5–S1 | 8–12° |
Source: Data adapted from White, A.A. & Panjabi, M.M. (1990). Clinical Biomechanics of the Spine (2nd ed.). Lippincott Williams & Wilkins; and Pope, M.H. et al. (1986). Electromyographic studies of the lumbar spine. Spine, 11(5), 489–493.
Most of the movement during sitting happens at L4–L5. When a chair lacks proper pelvis support, users often collapse into 14–15° of flexion, placing them near the end range of that motion, where disc pressure and shear forces are highest.
The Precision Posture System is designed to hold users in a mid-range posture.
This is the biomechanical sweet spot
This may reduce anterior shear
This may lower compressive spinal loads
This mid-range alignment was confirmed through both human modeling and independent lab research.
University of WATERLOO VALIDATION
To evaluate how Anthros performs with real people during real work, the University of Waterloo conducted a comprehensive study comparing Anthros to the Herman Miller Gaming Embody. Sixteen adults (even split of men and women) performed one full hour of computer work in each chair while researchers measured spinal and pelvis position
The results show reduced posterior pelvic tilt in the Anthros chair:
2° less in males
4.2° less in females (Equivalent to a 10–20% disc pressure reduction)
Why this matters:
Posterior pelvic tilt = slouching → lumbar strain → early fatigue and pain.
Reducing it keeps the spine healthy and upright with less effort.
“THE CHAIR'S LOWER SUPPORT WAS EFFECTIVE IN RESTRICTING POSTERIOR ROTATION OF THE PELVIS… FACILITATING A POSTURE CLOSER TO NEUTRAL.”
— University of Waterloo Report, 2025
Modeled and Measured:
Digital Human Simulations
Using Simuserv’s digital biomechanics tools, disc pressure was simulated across postures:
| CONFIGURATION | SIMULATED DISC PRESSURE |
| Standard Office Chair | 0.7 MPa |
| Anthros Chair | 0.5 MPa |
| Tilt | 0.3 MPa |
This simulation aligns perfectly with the university findings — showing the two-part system’s ability to outperform traditional lumbar designs in load reduction and comfort.
Upper Back Alignment
LESS THORACIC FLEXION, MORE POSTURAL STABILITY
One of the most significant findings from the University of Waterloo Spine Biomechanics Lab was the effect of the Anthros dual-back system on thoracic spine posture — the critical upper segment that determines how upright or slouched a person appears while seated.
Measured Results:
A More Upright Spine
Participants sitting in the Anthros chair exhibited 3.9° to 5.6° less thoracic spine flexion than when sitting in a leading ergonomic competitor (Embody). This means the Anthros chair helped users maintain a more upright, naturally stacked upper spine — reducing the rounded “hunched” posture that often develops during prolonged sitting.
The differences were:
- Consistent across all users (both male and female)
- Sustained over time, even after an hour of seated work
- Most pronounced during reading tasks, where the Anthros upper back support reduced thoracic flexion the most (p < 0.001)
“Participants demonstrated an average 3.9°–5.6° less flexion of the thoracic spine when seated in Anthros compared to Gaming Embody… indicating that Anthros promotes a more upright and supported upper back posture during sitting.”
— University of Waterloo Report, 2025
How the Design Enables It
The Anthros two-part back is what prevents the upper back flexion. With the pelvis supported in neutral, the spine is brought into its natural curves. The hinged and tapered upper back support keeps users in contact with the backrest and provides balanced support at all times.
This design:
Prevents upper trunk collapse.
Distributes load across the thoracic area without impeding shoulder movement.
Encourages active alignment from pelvis to shoulders.
Together with the lower pelvic support, this creates a kinetic chain of alignment — stabilizing the pelvis, aligning the lumbar curve, and reducing thoracic rounding.
Combined Outcome:
Whole-Spine
Optimization
When considered alongside the lumbar and pelvis results:
Pelvis control reduced posterior tilt by up to 4.2° in females
Thoracic flexion decreased by up to 5.6°
Disc pressure dropped to 0.5 MPa (upright) and 0.3 MPa (tilt)
These combined effects form a whole-spine posture correction — maintaining mid-range motion, lowering compressive forces, and allowing the body to sit closer to its natural standing alignment even in prolonged sitting.
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Precision Posture System:
Designed for Every Body
Unlike rigid lumbar pads or single plane backs, this system accommodates the full range of human variation:
Encourages active alignment from pelvis to shoulders.
Aligns with individual pelvis landmarks.
Prevents uneven pressure or over-correction.
Every adjustment is designed to meet your body where it is — and bring it back into healthy alignment.
By reducing passive tissue strain, disc deformation, and end-range spinal loading, it helps preserve long-term spinal integrity.
SCIENCE yOU CAN Sit On
This isn’t comfort marketing — it’s biomechanics in action.
Independent university testing and 3D human modeling confirm that the Precision Posture System offers benefits for:
Office professionals working long hours at a desk.
Gamers seeking posture endurance and reduced fatigue.
Long sitters managing spinal conditions.
Pain sufferers who have to sit all day.
It’s not just a better chair design, it’s a redefinition of how we support the human body in sitting.
SEE FULL UNIV OF WATERLOO STUDY
