Spasticity and rigidity are types of hypertonia that differ in their causes and characteristics. Spasticity results from lesions to the pyramidal tract and involves either agonist or antagonist muscles that exhibit clasp knife rigidity. Rigidity occurs due to basal ganglia lesions, involves both agonist and antagonist muscles displaying lead pipe rigidity, and is not stretch sensitive.

1. DIFFERENCES
D R N I L E S H N K A T E , P R O F E S S O R , P H Y S I O L O G Y , / D I F F E R E N C E S Page 5
Difference Between
Spasticity & Rigidity.
Spasticity Rigidity.
1
Lesion – Occurs
in Pyramidal
tract lesions;
commonest
Internal
capsule
Occurs in Basal
Ganglia Lesions
so called Extra-
Pyramidal
Rigidity.
2
Muscles
involved – Only
one group
either agonist
or Antagonist.
Both Agonist &
Antagonist are
involved.
3
Hypertonia –
Clasp Knife
type of Rigidity.
Hypertonia –
Lead pipe or Cog-
Wheel type of
rigidity.
4
Rigidity –
Stretch
sensitive.
Rigidity – Not
Stretch sensitive.