View Our Chair Fitting Form — Click Here

Mid-Back 24/7 Ergonomic Performance for Intensive-Use Environments

The Office Master Maxwell MX84IU is a heavy-duty mid-back ergonomic task chair built for the demands of continuous multi-shift operation. Rated for 450 lbs and 24/7 use, it delivers the commercial-grade durability and ergonomic adjustability that call centers, dispatch teams, healthcare facilities, and security operations require — at a slightly lower profile than the tall-back MX88IU.

For standard-height users who need intensive-use performance without the added height of a full tall-back chair, the MX84IU is the right fit.

Key Features & Benefits

• 24/7 intensive use rating — Commercial-grade construction designed for continuous multi-shift operation, not just standard 8-hour office use
• 450 lb weight capacity — Heavy-duty frame and components rated for a broader range of users
• Mid-back design — Provides thorough lumbar and mid-back support for standard-height users; more compact profile than the MX88IU tall-back
• Adjustable lumbar support — Customizable lower back positioning to maintain proper spinal alignment across extended shifts
• Seat depth adjustment — Accommodates different leg lengths to ensure proper thigh support without pressure behind the knees
• Multi-position armrests — Height, width, and angle adjustable to reduce shoulder and neck strain (optional KR-200 armrests available)
• Pneumatic seat height adjustment — Smooth tool-free adjustment for optimal desk and monitor alignment
• Heavy-duty casters — Smooth movement on carpet or hard floor surfaces
• High-density foam seat cushion — Maintains supportive properties through continuous daily use
• Manufacturer's limited warranty included

Technical Specifications

• Model: Office Master Maxwell MX84IU
• Back Height: Mid-back
• Use Rating: 24/7 intensive use
• Weight Capacity: 450 lbs
• Seat Height: Pneumatic adjustment
• Lumbar: Adjustable
• Seat Depth: Adjustable
• Armrests: Multi-position height, width, and angle adjustable (optional KR-200 armrests)
• Casters: Heavy-duty (carpet or hard floor)
• Warranty: Manufacturer's limited warranty
• Manufacturer: Office Master

⚠️ Made-to-Order: Each chair is made-to-order based on your selections to ensure the best fit and performance. Because of this, orders are final—but we're here to help you get it right.

Ideal For

• Call centers and dispatch operations running multi-shift schedules
• Healthcare facilities with nursing stations and shared workstations
• Security monitoring and emergency operations centers
• Standard-height users who need 24/7 performance without a tall-back profile
• Organizations where worker comfort directly impacts performance and retention
• Users up to 450 lbs requiring a durable, properly rated ergonomic chair

Frequently Asked Questions

What is the difference between the MX84IU and MX88IU?

Both are 24/7-rated Maxwell chairs with 450 lb capacity and the same ergonomic adjustment platform. The MX88IU has a taller back height, providing additional upper back and shoulder support — better suited for taller users or those who want more comprehensive back coverage. The MX84IU is the mid-back version, ideal for standard-height users or environments where a lower-profile chair is preferred. Our specialists can help you determine which is right for your team.

What does "24/7 intensive use" rating mean?

A 24/7 rating means the chair is engineered and tested for continuous use across multiple shifts — not just a single 8-hour workday. The components, foam, and frame are built to maintain performance and structural integrity under constant use, which is critical in environments where the same chair may be used by multiple workers across day, evening, and overnight shifts.

What armrest options are available?

The MX84IU is available with no armrests or with KR-200 adjustable armrests offering height, width, and angle adjustment for proper shoulder and elbow positioning during intensive work tasks.

Is this chair suitable for healthcare environments?

Yes — the MX84IU is used in nursing stations, clinical workstations, and healthcare dispatch environments. Its 24/7 rating and 450 lb capacity make it well-suited for the demands of healthcare operations. Contact us to discuss configuration options for clinical use.

Can this chair be shared by multiple users of different sizes?

Yes — the adjustable lumbar, seat depth, seat height, and armrests allow each user to configure the chair to their body at the start of their shift. We offer ergonomic consulting services to help organizations set up adjustment protocols for shared workstations. Learn more here.

How long does delivery take?

As a made-to-order chair, lead times vary by configuration. Contact us for current estimates before placing your order.

Can I try this chair before ordering?

Yes — visit our Bay Area showroom where our certified specialists can walk you through the Maxwell line and help identify the right model for your environment. We offer ergonomic consulting services in-person and virtually. Schedule a consultation.

What warranty is included?

The MX84IU includes Office Master's manufacturer's limited warranty. Contact us for full warranty terms and coverage details.

Why Ask Ergo Works?

With 30+ years of ergonomic expertise, Ask Ergo Works specializes in sourcing and configuring seating solutions for demanding professional environments — including 24/7 operations, healthcare, and high-capacity workplaces.

• Certified specialists — Professional ergonomic certifications with experience in intensive-use and multi-shift environments
• Professional assessment process — We evaluate your environment, shift structure, and user profiles before recommending a configuration
• Personalized recommendations — Model, armrest style, and configuration selected for your specific operational needs
• Enterprise & B2B experience — Volume purchasing support for call centers, healthcare systems, dispatch operations, and corporate facilities
• Post-purchase support — Available after delivery to assist with setup, adjustment protocols, and ergonomic guidance

Need help choosing between the MX84IU and MX88IU for your team? We offer ergonomic consulting services to get it right the first time. Learn more and book a consultation.