Muscles & Movement Movement Studies 2009/10 MS 2009/10

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 MS 2009/10

Muscles What do we need muscles for? Think of 3 roles muscles have in the body MS 2009/10

Skeletal Muscle Are all skeletal muscles the same shape? How does the structure of skeletal muscle relate to its function? Palpate the following muscles on yourselves and try and determine what they feel like Are they the same shape/thickness? MS 2009/10

a c e d b MS 2009/10

Muscular Attachments Going back to our muscle examples what do you think they attach to? MS 2009/10

Muscular Attachments 1. Tendons E.g. Achilles tendon E.g. Biceps tendon MS 2009/10

Muscular Attachments II. Aponeuroses Sheets of collagen- connective tissue providing muscular attachment E.g. External Oblique MS 2009/10

Muscular Attachments III. Deep Fascia Compact collagen fibres More uniform direction E.g Tensor fascia latae MS 2009/10

Muscle attachments IV. Fleshy Muscle directly into bone MS 2009/10

Muscle Action For each of the joints listed name the key muscle groups which perform the movements at that joint with their approximate location and 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 Wrist MS 2009/10

Hip Knee Ankle Shoulder Elbow Wrist Flexors, extensors, abductors, adductors, rotators Knee Flexors, extensors Ankle Dorsiflexors, plantarflexors, invertors, evertors Shoulder Flexors, extensors, abductors, adductors, rotators Elbow Flexors, extensors Wrist Flexors, extensors, deviators MS 2009/10

Muscle Activity What happens to a muscle when it is activated? Shortens? Lengthens? Stays the same? MS 2009/10

Concentric Muscle tension exceeds resistance and it shortens the muscle Speed of muscle fibre shortening depends on resistance MS 2009/10

Eccentric Muscle tension is less than the resistance causing the muscle to lengthen whilst working Tension developed is less than the resistance MS 2009/10

Isometric Muscle does not change in length Tension produced never exceeds resistance Which muscle group is working hardest in this example? MS 2009/10

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? MS 2009/10

Analysis of Movement Look at each other walking: Analyse the movement in terms of: Identifying the main muscles working at the hip and knee during gait Identifying the type of contraction in each muscle group i.e. concentric, eccentric, or isometric MS 2009/10

Muscle Function As you raise your leg to place your foot on a step several different muscles are working Are they all functioning in the same way? MS 2009/10

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 MS 2009/10

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 Muscles which work to steady the origin of the prime mover Synergists Special form of fixator MS 2009/10

Muscle Range MS 2009/10 ‘Musculoskeletal Assessment’ Clarkson

Ranges of biceps muscle work Hold arm out straight and then move hand to 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 MS 2009/10

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? MS 2009/10

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 MS 2009/10

Tasks There are four tasks for you to work through Divide into 5 groups Use the texts available MS 2009/10

Task 1 Sit down from standing 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? MS 2009/10

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? MS 2009/10

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? MS 2009/10

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? MS 2009/10

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 MS 2009/10

Oxford/MRC grading scale Grade Muscle Activity No contraction 1 Flicker/trace contraction 2 Active movement with gravity eliminated 3 Active movement against gravity 4 Active movement against gravity and resistance 5 Normal power MS 2009/10

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 MS 2009/10