This is usually an injury which will need surgical repair. If you think you have ruptured your triceps or biceps tendon and are having difficulty straightening or bending your elbow you should see your GP and ask for a specialist hand surgeon referral.
The therapists at the Hand and Upper Limb Centre can help with your rehabilitation post surgery. Usually your recovery will involve initially protecting the arm in a sling or splint and then starting some gentle movements. Once tendon strength has returned you may be able to commence some strengthening and stretching exercises.