Can this sign be used for a knot in a muscle?
No, this sign is specifically for a physical knot in a string, rope, or tie. For a muscle knot, you would typically point to the affected area and use a sign for 'tight' or 'cramp', or you might simply fingerspell the word K-N-O-T depending on the context.
How do I sign 'untie a knot'?
To sign 'untie', you would typically use a sign that shows pulling things apart or loosening. You can start with your hands together in the 'knot' position and pull them apart while opening your fingers, or sign 'knot' followed by the sign for 'disconnect' or 'release'.
Does the handshape matter for this sign?
Yes, using the pinched 'O' or 'F' handshape is very important because it represents holding a thin object like a string, thread, or rope. If you were to use a full fist, it would look like you are handling a massive cable or something much thicker, changing the nuance.