The document outlines various muscle contractions, including isotonic (concentric and eccentric), isometric, and isokinetic, along with the principles and procedures for manual muscle testing (MMT) to evaluate muscle strength and endurance. It emphasizes the importance of assessing muscle performance in relation to functional activities and highlights factors affecting muscle strength, such as aging and specific medical conditions. Additionally, it addresses the limitations of MMT and the need for proper technique and patient positioning during assessments.

1. Definition
1. Ability of the muscle to exert force
2. Refers to ability of person to generate maximal
force using a muscle or group of muscles
Muscle endurance – ability to maintain repeated
contraction or force generated for prolonged
period of time

2. Types of muscle contraction
Isotonic contractions are those which cause the
muscle to change length as it contracts and causes
movement of a body part.
2 types of Isotonic contraction:
Concentric
• Concentric contractions are those which cause the
muscle to shorten as it contracts

3. • An example is bending the elbow from straight
to fully flexed, causing a concentric
contraction of the Biceps Brachii muscle

4. • Eccentric
• Eccentric contractions are the opposite of
concentric and occur when the muscle
lengthens as it contracts
• Eg This occurs when lowering the dumbbell
down in a bicep curl exercise

6. • Isometric Contractions
• Isometric contractions occur when there is no
change in the length of the contracting muscle
• Eg when you grip something, such as a tennis
racket

8. • Isokinetic Contractions
• Isokinetic contractions are similar to Isotonic in that
the muscle changes length during the contraction,
where they differ is that isokinetic contractions
produce movements of a constant speed
• Eg breaststroke in swimming, where the water
provides a constant, even resistance to the
movement of adduction

9. Manual muscle testing
Procedure for :
Evaluation of the function & strength of individual muscles and
muscles group
• based on effective performance of movement in relation to
1. Forces of gravity
2. Manual resistance through the available ROM

12. Muscle tone
• The resistance of muscle to passive elongation
or stretching
• It is state of muscle tension inside a muscle or
muscle group when it is at rest

13. Range of motion
• arc of motion that occurs at a joint or a series
of joints

14. Why evaluation ?
• Facilitate diagnosis - neuromuscular conditions
(e.g., spinal cord injury, peripheral nerve injury)
• Establish a baseline & assess intervention
effectiveness
• Determine whether weakness is limiting
performance

15. • Determine need for compensatory measures or
assistive devices on a temporary or long-term
basis
• Identify muscle imbalances that require
strengthening
• Determine appropriate orthotic intervention to
prevent deformity

16. Long handle reachers

17. Swivel Spoon with Built Up Handle

19. Universal cuff

20. Wrist support with universal cuff

21. Functional position – resting hand splint

23. • The examiner should test passive ROM prior
to performing a manual muscle test of muscle
strength because the grading of manual
muscle tests is based on completion of the
joint ROM

24. Evaluation
Evaluated by manual resistance, isokinetics
exercises ,pinch meters, and dynamometers
• Hand strength - hand dynamometer
• pinch strength - pinch meter

29. What OT assess
• MMT – both upper & lower limb
• Generally grasps & pinches are tested

30. • Unlike active ROM, passive ROM does not
depend on the subject’s muscle strength and
coordination

31. Limitation
• Inability to measure the patient’s muscle
endurance (number of times the muscle can
contract at maximum level)
• Muscle coordination (smooth, rhythmic
interactions of muscle function)
• Motor performance capabilities (use of the
muscles for functional activities)

32. • The manual muscle test cannot be used
accurately with patients who have spasticity

33. • In stroke muscles are often hypertonic
• Muscle tone & ability to perform movements -
influenced by primitive reflexes & position of the head
& body in space.
• Movements tend to occur in gross synergistic patterns
(several muscles and joints working together), which
makes isolating muscle action & joint movement
impossible for most patients

34. • Videos

36. Factors affecting Muscle strength
• As a person ages, skeletal muscle strength
decreases as a result of changes in fiber type
& motor unit distribution
• It is generally assumed that the increased
connective tissue results in decreased ROM &
increased muscle stiffness

37. Conditions
• Myasthenia gravis – autoimmune disease
causing muscle weakness

38. Principles of MMT
• lists both manual muscle testing (MMT) and
dynamometry as appropriate measures of muscle
strength
• Resistance applied at the end of the tested range
is termed a 'break test'
• Resistance applied throughout the range is
termed a 'make test’

39. BASIC RULES OF PROCEDURE THAT APPLY TO MUSCLE
STRENGTH TESTING
• Explain the procedure and demonstrate the
desired movement.eg next slide
• Place the subject in a position that offers the best
fixation of the body as a whole (usually supine,
prone, or side-lying)
• Stabilize part proximal to tested part or, as in the
case of the hand, adjacent to the tested part.

40. • "I'm going to test the strength of one of the
muscles that bends your elbow“
• "This is the movement pattern I want you to
do. Do it first on your uninvolved side."

41. • Place the part to be tested in precise
antigravity test position, whenever
appropriate, to help elicit the desired muscle
action & aid in grading
• Use test movements in the horizontal plane
when testing muscles that are too weak to
function against gravity

42. • Apply pressure directly opposite the line of
pull of the muscle or the muscle segment
being tested
• Use a long lever whenever possible, unless
contraindicated

43. Evaluation
• evaluated in several ways
• most precise method, is a test of individual
muscles
• assess the strength of groups of muscles that
perform specific functions at individual joints

44. • third way to evaluate muscle strength is by
observing the performance of ordinary
activities
• Apply uniform pressure; avoid localized
pressure that can cause discomfort

45. Clinical practice
• Explaining client about procedure ,take cultural
aspect into account
• If possible Remove clothing or restriction around
joint (not general rule )
• Positioning
• Make client comfortable

46. • Check if available passive ROM is available –
instructions clear
• Do not keep changing position often – check
muscles in one position & then change other
• Respect pain
• Record appropriately

47. • Start with grade 3
• Spasticity – voluntary control assessment
• Pain, swelling ,T/C/D

48. • Check bilaterally /unilaterally
• Consider weakness – avoid too many
repetitions
• Tone increased – individual MMT can’t be
done

54. • Diff - muscle tone ,muscle strength
• Scales used

55. Limitation of grading scale
• Muscle being tested may have no clinical
relevance
• There may be individual variation in reporting
• Only assesses muscles which are contracting
in a concentric manner
• The scale may not be applicable in all patients

56. References
• Introduction to occupational therapy ,4 th
edition , Jane Clifford O'Brien
• Joint structure & function ,4th
edition ,Cynthia
c .norkin
• Willard & Spackman’s occupational
therapy ,11th
edition , Elizabeth Blesedell
Crepeau..

57. • Muscles testing & function with posture &
pain,5th
edition, Florence Peterson
Kendall ,Elizabeth Kendall McCreary
• Essential of medical physiology ,6th
edition ,k
Sembulingam