This is a rare occurrence, but we have a solution for you! If you insert the tube and see the spring is aligned with the hole in the knee platform but it won't pop out, then this solution often works.
1. With the crutch fully assembled (except spring head not popped out into the hole) you must make certain that the clamp nut and bolt are very tight. This is done as a precaution to prevent rotation of the Foot / tube assembly.
Clamp Nut and Clamp Bolt installed tightly to prevent rotation
2. After walking several steps, inspect the hole to see if the push button spring head is now popped out. If it has popped out you may continue to use the crutch. If not, you will need to discontinue using the crutch and we can send a warranty replacement part.
3. To disassemble the crutch, you might need to use a probe (such as the clamp bolt) to push the spring head all the way inside the tube. Then place the knee platform on the ground and twist the foot to dislodge the foot tube from the socket.
If you are still unable to get the spring to pop out, please fill out a warranty form on our website here and we will send you a replacement.