Keiser A400 Biaxial Upper Back

The KEISER A400 Biaxial Upper Back is uniquely engineered to isolate the upper back through a natural, converging axis of rotation that no linear rowing machine can replicate. Its biaxial movement guides users into a deeper range of motion that activates the lats, rhomboids, and traps more completely — while the A400 touchscreen delivers the high-fidelity rep-by-rep data required for elite performance coaching and clinical rehabilitation.

• Unique biaxial axis of rotation — specifically tuned to the natural planes of upper back movement, guiding users into a deeper, more complete range of motion than any linear rowing machine
• Dynamic Variable Resistance — provides more resistance where you are mechanically strongest at the start of the pull, tapering as you weaken, ensuring efficient muscle challenge throughout the entire stroke
• Unilateral symmetry training — independent arms prevent the stronger side compensating; the A400 console provides separate left and right limb data for precise imbalance identification and correction
• Zero-shock loading — low-inertia pneumatic design removes weight stack momentum, protecting the sensitive connective tissues of the shoulder and upper back from jarring forces
• Load-velocity profiling and drop-off alerts — rep-by-rep velocity tracking identifies performance drop-offs and alerts the user when velocity dips below a set threshold for optimal set termination
• Precision thumb-button adjustment — 1 lb / 1 kg increments for exact resistance management between sets

Specifications

• Dimensions: 64" H x 51" W x 48" D (1,626 x 1,295 x 1,219 mm)
• Machine Weight: 244 lb (111 kg)
• Resistance Range: 0–356 lb (0–161 kg)
• Movement Type: Unilateral biaxial — independent arms on a converging axis
• Adjustment: 1 lb / 1 kg increments via thumb buttons
• Display: 15.6" colour touchscreen
• Metrics: Power, velocity, force, range of motion, bilateral symmetry
• Connectivity: Wi-Fi and Bluetooth

Stocked at FSC Mayfair because the A400 Biaxial Upper Back delivers an upper back training stimulus that is simply not achievable with any other machine — and the data to prove every rep counts.