Musculoskeletal II- Dynamometry, End-Feel, Description of joints, Dermatome testing, resistive testing, Types of contraction, and muscle physiology

Question 1

Type I vs Type II Muscle fiber classifications

Answer 1

• Type I- aerobic, red, tonic, slow twitch, slow oxidative
• Type II- anaerobic, white, phasic, fast twitch, gast glycolytic

Question 2

Type I vs Type II- Functional characteistics of muscle fibers

Answer 2

• Type I- low fatigue, high capillary density, high myoglobin content, smaller fibers, extensive blood supply, large amount of mitochondria (ex marathon, swimming)
• Type II- high fatiguability, low capillary density, low myoglobin content, large fibers, less blood supply, fewer mitochondria (ex high jump, sprinting)

Question 3

Muscle receptors- Muscle spindle

Answer 3

• distributed throughout belly of muscle
• function to send info to the nervous system about muscle length and/or rate of change of its change
• spindle if important in the control of posture, and with the help of the gamma system, involuntary movements

Question 4

Muscle receptors- Golgi tendon organ

Answer 4

• encapsulated sensory receptors through which muscle tendons pass immediately beyond their attachment to the muscle fibers
• very sensitive to tension especially when produced from an active muscle contraction
• the function to transmit info about tension or the rate of change of tension within the muscle
• average of 10-15 muscle fibers usually connected in series with each golgi tenson organ
• stimulated through the tension produced by muscle fibers
• GTO provide the nervous system with instantaneous information on the degree of tension in each small muscle segment

Question 5

Concentric

Answer 5

• muscle shortens and develops tension

Question 6

Eccentric

Answer 6

• muscle lengthens and develops tension

Question 7

Isometric

Answer 7

• occurs when tension develops, but there is no change in the length of the muscle
• often against immovable objects

Question 8

Isotonic

Answer 8

• occurs when muscle shortens or lengthens while resisting a constant load

Question 9

Isokinetic

Answer 9

• occurs when the tension developed by the muscle, while shortening or lengthening at a constant speed, is maximal over the full range of motion
• ex biodex

Question 10

Resistive testing- Upper extremity (C1-T1)

Answer 10

• Cervical rotation (C1)
• Shoulder elevation (C2-C4)
• Shoulder abduction (C5)
• Elbow flexion (C5-C6)
• Wrist extension (C6)
• Elbow extension (C7)
• Wrist flexion (C7)
• Thumb extension (C8)
• Finger adduction (T1)

Question 11

Reflex testing- Upper extremity (C5-C7)

Answer 11

• Biceps (C5)
• Brachioradialis (C6)
• Triceps (C7)

Question 12

Dermatome testing- Upper extremity (C2-T1)

Answer 12

• Posterior head (C2)
• Posterior lateral neck (C3)
• Acromioclavicular joint (C4)
• Lateral arm (C5)
• Lateral forearm and thumb (C6)
• Radial distal phalanx, middle finger (C7)
• Little finger and ulnar border of the hand (C8)
• Medial forearm (T1)

Question 13

Functional testing (L4-S1)

Answer 13

• heel walking (L4-L5)
• toe walking (S1)
• SLR (L4-S1)

Question 14

Resistive testing- Lower extremity (L4-S1)

Answer 14

• hip flexion (L1-L2)
• knee extension (L3-L4)
• ankle dorsiflexion (L4-L5)
• great toe extension (L5)
• ankle plantar flexion (S1)

Question 15

Reflex testing- Lower extremity (L4-S1)

Answer 15

• patella (L4)
• achilles (S1)

Question 16

Dermatome testing- Lower extremity (L2-S5)

Answer 16

• anterior thigh (L2)
• middle third of anterior thigh (L3)
• patella and medial malleolus (L4)
• fibular head and dorsum of foot (L5)
• lateral and plantar aspect of foot (S1)
• medial aspect of posterior thigh (S2)
• perianal area (S3-S5)

Question 17

Ideal plumb line alignment (pg70)

Answer 17

• slightly posterior to coronal suture
• through the external auditory meatus
• through the axis of the odontoid process
• midway through the tip of the shoulder
• through the bodies of the lumbar vertebrae
• slightly posterior to the hip joint
• slightly anterior to the axis of the knee joint
• sightly anterior to the lateral malleolus
• through the calcaneocuboid joint

Question 18

Loose packed position

Answer 18

• stress on joint- minimal
• congruency of joint- minimal
• ligament position- great laxity
• joint surface- no volitional seperation

Question 19

Close packed position (pg 71)

Answer 19

• stress on joint- maximal
• congruency of joint- full
• ligament position- full tightness
• joint surface- compressed

Question 20

Normal end feel

Answer 20

• firm (stretch)
  
  • ankle df, finger ext, hip ir, forearm supination
• hard (bone to bone)
  
  • elbow extension
• soft (soft tissue approximation)
  
  • elbow flx, knee flx

Question 21

Abnormal end-feel

Answer 21

• empty (cannot reach end-feel, usually due to pain)
  
  • joint inflammation, fracture, bursitis
• firm
  
  • increased tone, tightness of capsule, ligament shortening
• hard
  
  • fracture, OA, osteophyte formation
• soft
  
  • edema, synovitis, ligament instability/tear

Question 22

Dynamometry basics

Answer 22

• measuring forces thata re doing work
• measures strength through the use of a load cell or spring loaded gauge

Question 23

Handheld dynamometry (pg 76)

Answer 23

• can be used to assess the grip strength of a patient
• normaly, dominant grip strength 5-10 pounds greater than non-dominant grip strength
• also used to measure muscle group strength by having patient exert maximal force against dynamometer

Question 24

Isometric dynamometry (pg 76)

Answer 24

• measures static strength of a muscle group without any movement
• extremity restrained by stabilization straps or stabilized with only verbal instruction
• conraindicated for acute orthopedic injury, fractures, or significant hypertension
• inability to convert data to functional activities

Question 25

Isokinetic dynamometry (pg 76)

Answer 25

• measures strength of a muscle group during a movement with constant, predetermined speed
• alters tension to accomodate for the change on length-tension ratio and lever arm throughout the entire arc of motion
• therefore, muscle group contracts maximally throughout motion
• common speeds are 60, 120, 180 deg per sec
• does not correlate to function since same velovity throughout
• patient will never have more resistance than they can handle throughout