Gymnic Physio-Roll Ball, 22 Inches, Yellow The Gymnic Physio-Roll Yellow Fitness Ball provides an ideal medium for balance and strength training. Physio-Roll's saddle-like seat provides stability, comfort and confidence, so clients of every age and nearly every diagnosis may participate in ball therapy. Unique shape of the ball helps the therapists with activities that might otherwise be risky on a traditional ball. Measures 22 inches. Ideal for special needs therapy and sensory stimulation Middle saddle-like seat allows more control and balance Like a therapy ball, helps with balance, muscle tone and sensory stimulation Limited to forward and backward rotation while holding the rider within a contoured "saddle" Provides control and stability