What are the causes of muscle weakness in the legs?
Muscle weaknesses manifest themselves preferentially in the extremities, including the legs, and only affect the respiratory or swallowing muscles at a later stage. There are a number of muscle-specific diseases that lead to a weakening of the leg muscles. These include myasthenia gravis, multiple sclerosis, botulism, spinal muscular atrophies, Duchenne muscular dystrophy in childhood, and amyotrophic lateral sclerosis in old age.
Another cause of muscle weakness in the legs is a herniated disc. Depending on the severity and location in the lumbar or sacral spine, certain muscle groups in the leg can be affected. In the case of a nerve compression, for example in the context of a herniated disc, it can lead to initial sensations of numbness and tingling, muscle weakness and even muscle paralysis.
Often affected are the intervertebral discs between the vertebrae L4, L5 and S1. In the case of L4 syndrome, muscle weakness can be recognized by reduced knee extension, in the case of L5 and S1 syndrome by reduced foot elevation and foot lowering. In addition to the triggers mentioned so far, general illnesses that do not directly affect the leg muscles can also cause muscle weakness there. These include, for example, depression, metabolic disorders such as hypothyroidism, anaemia or infectious diseases. It is important that those affected by prolonged muscle weakness have a neurological examination to rule out serious diseases.
What are the causes of muscle weakness in the arms?
As with muscle weakness in the legs, the arms, as part of the extremities, are considered a common site of manifestation. A weakening of the arm muscles triggered by the spinal column can be caused by a herniated disc at vertebral level C5-C8. Here, for example, the biceps can no longer be sufficiently innervated in the context of a C6 syndrome, which leads to its weakening, resulting in a weakening of the arm flexion.
Otherwise, various general diseases such as hypothyroidism, vitamin deficiency or stress can cause muscle weakness. In the same way, diseases that specifically affect the musculature, such as spinal muscular atrophy, myasthenia gravis, multiple sclerosis or amyotrophic lateral sclerosis are also to be mentioned here. A new aspect as a reason for a weakening of the arm muscles is stroke.
Due to an undersupply of oxygen to certain areas of the brain in the event of cerebral haemorrhage or blockage of the blood vessels supplying the blood, i.e. thrombosis or embolism, various functions and structures can be affected. If the stroke occurs in an area that represents the arm, the arm muscles can weaken and even become paralyzed. In general, long-lasting muscle weaknesses in the arms definitely require clarification.
