This document discusses trick movements, or unnatural movements that occur when a muscle is paralyzed or inhibited. It defines trick movements and describes several types: direct/indirect substitution where another muscle takes over the action of the paralyzed prime mover; accessory insertion where a muscle's insertion allows it to assist a weak muscle's movement; tendon action where shortening of a tendon produces movement; rebound where relaxation of an antagonist muscle causes apparent agonist contraction; and gravity assistance where body positioning uses gravity to assist weak muscles. Examples are provided for each type of trick movement.

1. Trick Movements (Manual Muscle
Testing)
MANALI DESAI (PT)

2. Manali S. Desai (PT)
At the end of today’s lecture, you will
understand
What is trick movement?
Types
Examples of each types

3. Manali S. Desai (PT)
Definition
Unnatural movements seen when muscle is paralysed or inhibited
It is taking over the action of prime mover when paralysed by another group of
muscles
Also known as substitution movement

4. Manali S. Desai (PT)
Types
Direct / indirect substitution
Accessory insertion
Tendon action
Rebound
Gravity

5. Manali S. Desai (PT)
Direct / indirect substitution
A) Another prime mover will substitute for paralysed prime mover muscle
Eg: 1) weakness / paralysis of supinator
Muscle substituted Trick movement
biceps will substitute Supination along with elbow flexion

6. Manali S. Desai (PT)
B) Fixator muscle will produce movement for prime mover / agonist muscle
Eg: hip abductors weak / paralysed
Muscle substituted Trick movement
Lateral abdominals will substitute Pelvis elevation

7. Manali S. Desai (PT)
C) Other favorable muscle placed in the region, will contract to position the joint in a new
position so that other muscle with respect to new position performs test motion
Eg: If Deltoid paralysed
Favourable muscle New position Other muscle
External rotators Externally rotate Biceps will contract to
produce shoulder
abduction

8. Manali S. Desai (PT)
D) Other muscle may contract to assist weak muscle
Eg: if biceps weak / paralysed
Muscle substituted Trick movements
Shoulder flexors Shoulder flexes during elbow flexion

9. Manali S. Desai (PT)
Accessory Insertion
The insertion of muscle is such that when muscle contracts, it helps to perform
movements of the weak paralyzed muscles.
Eg: if EPL paralyzed/ weak
Substituted muscle Insertion Trick movement
APB & FPB Base of proximal phalanx
and extensor expansion
Extension of thumb

10. Manali S. Desai (PT)
Tendon action
Occurs in two joint muscle or multi joint muscle.
Shortening of a tendon when antagonist muscle contracts strongly.
Eg: if long finger flexors weak/ paralyzed
Trick movement Passive insufficiency Tendon action
Wrist extension Wrist flexors Finger flexion

11. Manali S. Desai (PT)
Rebound
Phenomenon of seeming contraction in the agonist when the antagonist contracts strongly and
then relaxes quickly.
Eg: if long finger flexors weak/ paralysed
Antagonist contract Trick movement
EPL Finger flexion

12. Manali S. Desai (PT)
Gravity
Patient will shift the body part so that gravity assists the weak muscles to do the movement
E.g.: If triceps weak / paralysed
Shift the body part Trick movement
shoulder abducted 90 degree Shoulder depression & external rotation

13. Manali S. Desai (PT)
References
Parry CBW. Trick Movements. Proceedings of the Royal Society of Medicine. 1970;63(7):674-676.
Kendall, F. (2005). Muscles Testing & Function with Posture & Pain ( 5th edition). Lippincott
Williams & Wilkins.
Avers, D. (2019). Daniels & Worthingham’s Muscle Testing, Techniques of Manual Examination &
performance Testing (10th edition). Elsevier.