I would need to know more details from your unfortunate fall accident from the ladder in order to properly assess your claim. From the limited facts, you may have a case against the manufacturer if the ladder was defective. For example, if you properly used the locking mechanism prior to using it, and the locking mechanism failed or buckled causing you to fall, then the locking mechanism may be defective. If it is defective, then you would have a products liability claim against the manufacturer.
There may also be other parties liable for your accident. For example, if you rented the ladder from a store, the store may also be liable for your injuries if they did not properly inspect and maintain the ladder prior to renting it to you.
Products liability cases in Pennsylvania and New Jersey can be complicated, and it is important that you speak to an experienced defective product accident lawyer to explore your legal options. Feel free to contact me, and I will be more than happy to discuss your case. 877.944.8396