If the difference between R1 and R2 is large, what does this indicate?

If the difference between R1 and R2 is large, what does this indicate?

• A. Hypotonia
• B. Normal ROM
• C. Spasticity
• D. Contracture

Answer: (C)

When you assess tone with R1 and R2, R1 is the angle of first resistance during a fast stretch and R2 is the angle reached with a slow stretch. A large difference between these two angles means the resistance kicks in early during rapid movement but the limb can move much farther when the stretch is slow. This reflects a velocity-dependent increase in tone from an overactive stretch reflex, i.e., spasticity. If the difference were small, the limitation would be more due to fixed tissue length (contracture) rather than neural hyperexcitability. Hypotonia would show reduced resistance overall, and normal ROM would show little to no such discrepancy.

When you assess tone with R1 and R2, R1 is the angle of first resistance during a fast stretch and R2 is the angle reached with a slow stretch. A large difference between these two angles means the resistance kicks in early during rapid movement but the limb can move much farther when the stretch is slow. This reflects a velocity-dependent increase in tone from an overactive stretch reflex, i.e., spasticity. If the difference were small, the limitation would be more due to fixed tissue length (contracture) rather than neural hyperexcitability. Hypotonia would show reduced resistance overall, and normal ROM would show little to no such discrepancy.