This document provides an overview of muscle anatomy and physiology. It discusses the different types of muscles in the body, including voluntary, involuntary, and cardiac muscles. It describes the microscopic structure of muscle fibers and myofibrils. It explains the three types of muscle actions: isometric, concentric, and eccentric. It also discusses muscle injuries, rehabilitation, and the relationship between muscles and nerves via myotomes and dermatomes.

1. A Interactive Apporach Of Muscles
(Complete Info ppt.)
By- Dr. Armaan SinghBy- Dr. Armaan Singh

2. Muscle Strains
 Tend to occur at the
musculotendinous junction
 At the muscle fibers
 At the tendon or tenoperiosteal
junction
 It is essential to know the origin and
insertion of a muscle, to assess it
correctly
 Passively stretching the muscle
 Testing its isometric, concentric and
eccentric contractions

3. Types of Muscle
 Voluntary muscle
 Striated: somatic nerves
 Involuntary: smooth
 Autonomic system
 Cardiac muscle
 Autonomic system

4. Voluntary Muscle
Consists of contractile element
 Muscle fibers which develop tension
 Non-contractile, connective tissue, of
which the tendon forms a major part
 Connective tissue transmits the force of
the muscle to the bones
 Helps protect the muscle tissue and
binds muscle fibers together
 Muscle fibres are grouped into bundles
called fasciculi

5. Muscle Fibres
 Are grouped into bundles called
fasciculi
 The size of fasciculi varies
 Muscles performing gross movements
have a larger number of fibres in each
fasciculus

6. Muscle Fibres
 Muscles performing fine movements have smaller
fasciculi
 Supplied by a greater number of nerve fibres

7. Fasciculi
 Arrangement of the fasciculi
determines the shape of the
muscle
 Amount of tension
 Speed of contraction
 Fasciculi contain fibres that are
either parallel or oblique

8.  An individual muscle cell is called a
muscle fibre
 Sarcoplasma is the cytoplasm of the
muscle fibre
 It is enclosed by the sarcolemma, a
plasma membrane
 Sarcoplasm contains
T- tubules which transport
substances
 Sarcoplasmic reticulum stores
calcium
Muscle Fibres

9. Myofibrils
 Myofibrils are made up of
sarcomeres
 Smallest functional unit of a
muscle
 Sarcomere is composed of
filaments of myosin and actin
responsible for contraction
 Myosin is thick filament
 Actin is thin filament
 Tropomyosin and troponin are
attached to Z-disc

10. Muscle
 Epimysium around muscle
 Perimysium around fasciculi
 Endomysium around muscle cell
 Bundles of muscle cells or fibre
 Myofibril consists of myofilament
actin myosin filament

11.  Muscle belly with two tendons
 Two heads : biceps
 Three heads : triceps
 Four heads : quadriceps
Muscle Types

12.  Short muscle fibres are connected
together by tendinous intersections.
 They develop from myotomes
 Have a segmental nerve and blood
supply
 Each segment has a short range of
contraction
 The range of the muscle is the sum of
the segments
 e.g. rectus abdominus muscle or
sternomastoid
Parallel Fibres

13.  Long muscle fibres are found in strap
muscles
 They can shorten a great deal
 Producing a large range of movement,
e.g. the sartorius
Parallel Fibres

14. Oblique Fibres Pennate Muscles
 Unipennate – muscle fibres are
confined to one side of the tendon,
e.g. unipennate lumbrical from
flexor pollicis longus
 Bipennate – fibres on both sides of
the tendon, e.g. bipennate
lumbrical, rectus femoris
 Multipennate – muscle fibres attach
and converge on several tendons
e.g. deltoid

15. Sphincter
 Circular fibres, true sphincter has no bony
attachments
 Deep portion of external anal sphincter

16.  Muscle can only act on a joint, if it
crosses the joint
 Muscles that have a common action on
the joint, tend to have same nerve
supply
 Exception, flexors of the elbow, have
several different nerves
 Nerve supplying the muscle, gives an
articular branch to joint
Muscles

17.  Tendons, consist of type I collagen
 Form a connection between the
muscle belly and its attachments
Tendon

18. Musculotendinous Junction
 Junctional area between muscle
and tendon
 Growth plate of muscle
 Subjected to great mechanical
stress
 Muscles tend to tear at
musculotendinous junction

19. Muscle Attachments
 Muscles are attached to bone by
tendons
 There is a gradual transition from
tendon to fibrocartilage to lamellar
bone via the periosteum
Benjamin & Ralphs, 1986; Benjamin et al., 1996

20. Osteotendinous Junction
 Four zones
 Pure fibrous tissue
 Unmineralised fibro-cartilage
 Mineralised fabricating
 Bone
Benjamin et al., 1986

21. Force of Muscle
 The force of a muscle depends
on its physiological cross-section
area
 Strap muscles are weaker than
pennate muscles

22.  Some muscles cross two joints
 Hamstrings:
semi-membranosus,
semitendinosus, long head of
biceps femoris
 Medial and lateral heads of
gastrocnemius, plantaris
 Rectus femoris portion of
quadriceps
 More likely to be injured
Muscles

23. Muscle Tears

24. Muscle Tears

25. Skeletal Muscle Action
 No muscle acts alone
 Muscles usually act in groups
 The major muscle which initiates
movement, is called the agonist (prime
mover)
 Antagonists have the opposite action
 Synergist muscles act as stabilisers or
fixators

26.  Synergists help to steady the
part being moved
 Fixators stabilise the attachment
of the prime mover
 Enable it to work more efficiently
 Flexing the elbow, brachialis is
the prime mover
 Biceps brachii and the brachioradialis are synergists
 Fixators are muscles around the shoulder joint; the rotator cuff
muscles stabilise the head of the humerus
Muscle Action

27. Muscles
 Muscles develop from mesoderm
 Myotomes are a group of voluntary
muscles supplied by a specific nerve root
 A dermatome is an area of skin supplied
by a specific nerve root
 They generally tend to follow the
segmental supply of the underlying
muscles

28. Myotomes
 Four consecutive spinal segments
 Control each lower limb joint
 Hip L2,3,4,5
 Knee L3,4,5, S1
 Ankle L4,5, S1,2

29. Myotomes
 Flexion of hip
 Iliopsoas L2,3
 Extension of hip mainly gluteus
maximus and hamstrings, L4,5
 Extension of knee
 Quadriceps L3,4
 Flexion of knee L5, S1

30. Myotomes
 Dorsiflexion of ankle
tibialis anterior (TA) L4,5
 Extensor hallucis longus
L5
 Plantar flexion of ankle
 Posterior muscles of calf
S1,2

31.  Inversion and dorsiflexion
 Tibialis anterior L4 inversion and
plantar flexion
 Tibialis posterior L4
Inversion

32. Plantar flexor and evertor
 Peroneus longus
 Peroneus brevis L5,S1
Dorsiflexor and evertor
 Peroneus tertius L5,S1
Evertors

33.  Skin
 Bones
 Muscles / tendons
 Nerves
 Blood vessels
Dermatomes

34. Dermatomes Lower Limb

35. Types of Muscle Action

36. Voluntary Muscle Action
Three types
 Isometric
 Concentric
 Eccentric

37. Isometric Action
 No change in the length of
the muscle fibres
 Increase in tension
 Least stress to the muscle
 First phase in the
rehabilitation of a muscle tear
or strain

38. Isometric Action
 Isometric produces an
increase in strength only at
the joint angle at which it is
performed
 It should only be done for
short periods
 Muscle fatigue due to
restriction of the blood supply

39.  The origin and insertion move
towards each other
 The muscle shortens as it
increases its tension
 It is the traditional action in
books
 Second phase of the rehabilitation
of a muscle
 Pulling up on a bar
 Elbow flexors work concentrically
Concentric Action

40.  Muscle lengthens as it develops
tension
 Elbow flexors when lowering
yourself from a bar
 Eccentric action is the most
powerful action
 It is the most stressful
 The last phase in muscle
rehabilitation
Eccentric Action

41. Musculoskeletal Injuries
Extrinsic factors
Sport
Contact sports
Environment
Equipment
Protective
Overuse
Intrinsic factors
Physical
Physiological
Psychological
Previous Injury
Inadequate rehabilation

42. Muscle Injuries
 Damage to muscle fibres heal relatively
quickly because of their rich blood
supply
 If tendons are damaged, healing is
slower due to their relatively poor blood
supply
 If the injury is close to the bone, e.g. a
blow to the vastus intermedius
 May develop myositis ossificans
 These injuries usually take
longer to heal

43. Muscle
 Pre-stretching the muscle prior to a
concentric muscle action
 Increases the force because of elastic
recoil
 Long jumpers stretch the extensor
muscles in the downward sink on to the
board before take-off
 Wind-up or cocking phase in bowling a
ball in cricket
 If it is stretched more than 120% then
its force of contraction decreases