As the disease continues to progress through the adolescent years, weakness in the muscles typically accelerates and other signs and symptoms may become apparent:
- Overwhelming fatigue
- Respiratory compromise or muscle weakness leading to respiratory infections
- Grooved tongue (with deep fissures, cracks, and grooves)
- Gradual decline in muscle effectiveness (muscle atrophy)
- Arm and leg weakness
- Joint instability
- Joint dislocation
- Numbness and tingling or pain in hands and feet
- Diminished or lack of deep tendon reflexesA tendon is a tough cord or band of dense white fibrosis connective tissue that unites a muscle with another part (for example a bone) and exerts a reflex action in which a muscle is made to contract by a blow upon its tendon. (areflexia)
- Inability to sense the orientation of body parts and balance issues (proprioception)
- Difficulties with balance and proprioception (inability to sense)
- Decreased response to touch below the knee
- High arches and drop foot (difficulty lifting the front part of the foot) or flat feet
