Difference Between Spasticity and Rigidity (With Table)

Spasticity occurs when continuous tightness occurs in the number of muscles. Upper Motor lesion in the pyramidal tract causes spasticity. The stiffness affects normal movement. It is uni-directional. In this brain and spinal cord get damaged. It causes by fast movements. A person seizes its motion when the joint is not able to make a move. Many symptoms cause spasticity.

Rigidity refers to the state in which a person is unable to bend, twist or stretch. It is bi-directional. It is seen in extrapyramidal tracts. It refers to a state of deformity under pressure. There is a disease called Parkinson’s disease, which is a particular type of neurological disease. High fever and decreased appetite cause rigidity in a person.

Comparison Table Between Spasticity and Rigidity

What is Spasticity?

Spasticity happens when numerous muscles suffer stiffness. It occurs in one direction. When a person tries to move a joint, then spasticity seizes the movement. Spasticity damages the neuron cells of the spinal cord and brain.

It is a common symptom of Multiple Sclerosis. It is caused by myelin and nerve fibers. The messages from the central nervous system do not reach the spinal cord in this condition. The degeneration of myelin causes spasticity.

Myelin is a fatty white substance that forms an insulating membrane. It also occurs due to the contraction of the extensor muscles. Cerebral palsy causes spasticity. Spasticity also causes acquired brain trauma and stroke.

Spasticity causes pain and weak coordination. Many symptoms cause spasticity. Muscle tone rises and causes rigidity which is called hypertonicity. Nocturnal awakening is one of the symptoms of spasticity.

Tense muscles, jerky movement, non-proper positioning of the arm, wrist, or any other body part-Clonus, which are uncontrollable muscle spasms, is one of the symptoms of spasticity. Velocity is a major factor in spasticity due to faster movements.

The stretch reflex exhibits abnormal high muscles. Spasticity is visible with fast movements. The contraction of extensor muscles causes deep pain in joints and weak coordination. Upper Motor lesion in the pyramidal tract causes spasticity.

What is Rigidity?

Rigidity is muscle tension or rigor. It is bi-directional. The problem in the movement can be sensed despite the speed and direction. It is visible in extrapyramidal lesions.

Wilson’s disease is which copper metabolism occurs in the lungs, liver, brain, and other tissues. Catatonia, acute cerebral infarction, basal ganglia, lupus are some of the causes of rigidity.

Viral and bacterial infections are one of the causes of rigidity. Lupus is a chronic disease that causes stiffness in the joints. There is a syndrome which is known as Steele-Richardson-Olszewski, which also causes Rigidity.

Rigidity occurs when nerves get pinched. Bradykinesia is slowness in movement, which is one of the causes of rigidity. High fever and decreased appetite cause rigidity in a person. Flexors and extensors can both affect rigidity.

The velocity does not affect rigidity. Speed is not a factor in rigidity. Rigidity leads to Parkinson’s disease. Muscle cramps, muscle weakness, pain, stiffness leads to rigidity. It is bi-directional. It is seen in extrapyramidal tracts.

It refers to a state of deformity under pressure. Muscle pain is caused by rigidity. Rigidity arises when muscles are unable to relax normally.

Main Differences Between Spasticity and Rigidity

1. The contraction of muscles is known as spasticity, whereas Rigidity is the state of unable to bend.
2. Arms, neck, and lungs are most affected by spasticity, but Rigidity can disturb any body part.
3. Unusual posture can lead to Spasticity, whereas cramps can lead to Rigidity.
4. Velocity matters in Spasticity instead of Rigidity have no relation with velocity.
5. Spasticity occurs in pyramidal tract lesions, whereas Rigidity occurs in extrapyramidal tracts.
6. Spasticity happens with hyperreflexia, whereas Rigidity happens with hyporeflexia.

Conclusion

Spasticity arises due to the pulling of muscles, and Rigidity arises due to the inability to bend. Spasticity also causes acquired brain trauma and stroke. Spasticity causes pain and weak coordination. Many symptoms cause spasticity.

Muscle tone rises and causes rigidity which is called hypertonicity. Nocturnal awakening is one of the symptoms of spasticity. Other symptoms include Tense muscles, jerky movement, non-proper positioning of the arm, wrist, or any other body part. Clonus, which are in layman’s language known as uncontrollable muscle spasms, is one of the symptoms of spasticity.

Velocity is a major factor in spasticity due to faster movements. The stretch reflex exhibits abnormal high muscles. Spasticity is visible with fast movements. Bradykinesia is slowness in movement, which is one of the causes of rigidity.

High fever and decreased appetite cause rigidity in a person. Flexors and extensors can both affect rigidity. However, the velocity does not affect rigidity. Speed is not a factor in rigidity. Rigidity leads to Parkinson’s disease.

Muscle cramps, muscle weakness, pain, stiffness leads to rigidity. It is bi-directional. Clasp knife hypertonia occurs in Spasticity, whereas lead pipe hypertonia occurs in Rigidity. Spasticity affects antagonist or agonist muscles. Rigidity affects both antagonist and agonist muscles.

References

1. https://europepmc.org/article/med/3288246
2. https://www.sciencedirect.com/science/article/pii/B9780444895967500122