Muscles & Movement

1. Muscles & Movement Movement Studies 2011-2012 Adapted from 2010 slides produced by LS & SN Movement Studies 2011/12

2. Class conduct - practical labs University of Hertfordshire MS 2011/12

3. Learning Outcomes • Describe the different types of muscle attachment • Explain how muscles can contribute to movement and stability • Perform movement analyses in terms of: • the functional relationship of relevant muscles • the type of muscle contraction • the ‘range’ a muscle is working in/through Movement Studies 2011/12

4. Muscles • What are the functions of muscle within the body? Movement Studies 2011/12

5. Skeletal Muscle • Are all skeletal muscles the same shape? • Parallel – fascicles parallel to long axis (cylindrical/spindle or flat bands/straps) • Convergent – fibres are spread out & converge at common attachment • Unipennate – (feather) fascicles form a common angle with tendon (less tendon mvt, stronger) • Bipennate - fasicles on both sides of tendon • Multipennate- tendon branches in muscle belly • Circular - or sphincter, (diameter opens/closes) Movement Studies 2011/12

6. Muscle Palpation • Palpate the following muscles on yourselves and try and determine what they feel like • Are they the same shape/thickness? Movement Studies 2011/12

7. c a d b e Movement Studies 2011/12

8. Muscular Attachments Going back to our muscle examples what do you think they attach to? Movement Studies 2011/12

9. Muscular Attachments • 1. Tendons • E.g. Achilles tendon • E.g. Biceps tendon Movement Studies 2011/12

10. Muscular Attachments • II. Aponeuroses • Sheets of collagen- connective tissue providing muscular attachment • E.g. External Oblique Movement Studies 2011/12

11. Muscular Attachments • III. Deep Fascia • Compact collagen fibres • More uniform direction • E.g Tensor fascia latae Movement Studies 2011/12

12. Muscle Action For each of the joints: • name the key muscle groups which perform the movements at that joint • identify their approximate location • (try to give an example) e.g. the hip flexors are located on the anterior surface of the hip joint and thigh and include iliopsoas • Hip • Knee • Ankle • Shoulder • Elbow & Forearm • Wrist Movement Studies 2011/12

13. Hip • flexors, extensors, • abductors, adductors, • rotators (int/ext = med/lat) • Knee • flexors, extensors • Ankle • dorsiflexors, plantarflexors, • Invertors, evertors • Shoulder • flexors, extensors, • abductors, adductors, • rotators (int/ext = med/lat) • Elbow • flexors, extensors • Forearm • Pronators, supinators • Wrist • flexors, extensors, deviators (rad/ulnar dev) Movement Studies 2011/12

14. Muscle Activity What happens to a muscle when it is activated? Does it….. • Shorten? • Lengthen? • Stay the same? Movement Studies 2011/12

15. Inner range Outer range Movement Studies 2011/12

16. Concentric • Muscle tension exceeds resistance and it shortens the muscle • Speed of muscle fibre shortening, depends on resistance Movement Studies 2011/12

17. Eccentric • Muscle tension is less than the resistance causing the muscle to lengthen whilst working • Tension developed is less than the resistance Movement Studies 2011/12

18. Isometric • Muscle does not change in length • Tension produced never exceeds resistance • Which muscle group is working hardest in this example? Movement Studies 2011/12

19. Muscle Contraction • Why are there different types of muscle contraction? • Straighten your leg while sitting: Which muscles are working? • What sort of muscle work is occurring in the quadriceps and hamstrings? • Where might isometric muscle contraction be happening? Movement Studies 2011/12

20. Analysis of Movement • Look at each other taking a slow step forwards - • Analysethe movement in terms of: • Identifying the main muscles working at the hip and knee during the step • Identifying the type of contraction in each muscle group i.e. concentric, eccentric, or isometric Movement Studies 2011/12

21. Group Action of Muscles • Muscles work in groups not singly • A number of muscles are active during any movement • It is this group action which results in co-ordinated movement • Muscles can be divided by function into prime movers/agonists, antagonists or fixators Movement Studies 2011/12

22. Functional muscle groups Prime mover/agonist • A muscle or muscle group which contracts to bring about movement Antagonists • A muscle or muscle group which opposes the prime mover and relaxes and lengthens progressively to control movement Fixators / Stabilisers • Muscle works to steady a bone as a steady base /origin from which the of the agonist /prime mover acts Synergists • muscle acts simultaneously with one or more muscles to produce a movement “act together” • true or helper synergists Movement Studies 2011/12

23. Muscle Range Movement Studies 2011/12 ‘Musculoskeletal Assessment’ Clarkson

24. Ranges of biceps muscle work • Start with your hand on your shoulder? • Where in range is your biceps muscle? • Take your arm back out to 90º now where in range are your biceps? • Now straighten fully – where in range are your biceps Movement Studies 2011/12

25. Ranges of iliopsoas* muscle work • Iliacus and psoas major work together functionally  iliopsoas • Sit on a plinth—where in range is your iliopsoas? • Lean forwards—where in range is your iliopsoas? • Stand up and straighten fully—where in range is your iliopsoas? Movement Studies 2011/12

26. IMPORTANCE OF MUSCLE RANGE • Why is it important to know where in range a muscle is working? • Inner range – often weak • Middle range – often used for muscle testing Movement Studies 2011/12

27. Tasks • There are four tasks for you to work through • Divide into 5 groups • Use the texts available Movement Studies 2011/12

28. Task 1 Standing to sitting: • Which lower limb muscle group is predominant in producing this movement? • How would you describe the type of muscle contraction in this muscle group? • What is the function of this muscle group? • In which range is the muscle group contracting at the start of the movement? Movement Studies 2011/12

29. Task 2 Stand on your left leg and flex your right knee • Which muscle group produces knee flexion? • Which muscle group is working as an antagonist? • What type of muscle contraction describes the right iliopsoas activity? • How would you classify the iliopsoas function in this case? Movement Studies 2011/12

30. Task 3 In standing raise your right foot on to a small step. • In which range are the quadriceps working the knee? • In which range are the hamstrings working at the knee? • Where in range do the quadriceps exert the greatest force? • Which muscles are working as stabilisers? Movement Studies 2011/12

31. Task 4 During a normal gait cycle look at dorsiflexion of the ankle • Where in range do the dorsiflexors contract concentrically? • Classify the type/s of contraction and function of the dorsiflexors that occur during the cycle? Movement Studies 2011/12

32. Muscle Assessment • Physios assess muscles for strength, length and control –these skills will be taught in NMS1 • One means of grading muscle power is the Oxford or MRC grading scale Movement Studies 2011/12

33. Oxford/MRC grading scale Movement Studies 2011/12

34. Conclusion • Make sure you are happy that the learning outcomes have been met • Familiarise yourself with the main muscles of the hip and knee and how their attachments vary – relate this to their function • Use your bones to determine where the muscles attach Movement Studies 2011/12

35. Resources • See Learning Support Pack • pp 4-5 Movement Studies 2011/12