Your joints feel weaker than normal

via google

Numbness or weakness in one or more of your limbs accompanied by blurred vision and slurred speech may indicate multiple sclerosis (MS), a disease that affects your brain and spinal cord. Multiple sclerosis is a progressive, often disabling disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body. It has no cure, but treatments can help manage symptoms.