Unit 4 reach and grasp notes PDF

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summary notes on the lecture of reach and grasp of rehab 2...

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Lecture 1 :- introduction Reaching is the major purpose of the arm, while interaction with the environment is the major purpose of the hand. Not re gaining upper limb strength and ability is associated with depression and lower quality of life. Lecture 2:- phases of reach and grasp There are four main phases of reach and grasp: 1. Transport phase (reach)- shoulder flexion, forearm and wrist movement 2. Stabilisation phase (holding onto it) 3. Manipulation phase (moving the object) within your hand 4. Release phase (letting go of it) Within release phase there are three sub-stages of steps to completing the movement: ● Stabilisation phase – grip and hold ● Manipulation – hand ● Release – adjusted grip, stabilisation of the object, releasing in a controlled manner ● Also have a visual and postural component (the two pre components that complete the phases) There are six components to completing a reach and grasp; 1. Vision (identification and location of object) 2. Postural adjustments 3. Transport Phase (reach) 4. Stabilisation Phase (grasping and holding onto it) 5. Manipulation Phase (moving object) within your hand 6. Release phase (letting go of it) Reach and grasp = vision + arm + hand+ postural adjustments Analysis of R&G: Object location (postural adjustments/ balance), object recognition, transport phase, stabilisation, manipulation and release. The role of vision in reach and grasp: 1. Object Location: when the object is in central vision only the eyes move, when placed in the near view it is viewed by the peripheral vision so both the eyes and head move. When the object Is in the far peripheral vision the eyes, head and trunk move. Each can be assessed separately and each may need training separately. 2. Object Identification: Visual information about the characteristics of the object is used to: improve accuracy of reach and hand shape. Also pre-programme the kinds of forces required for stabilisation

● Vision is required for object location and object recognition. It links with postural adjustments dependent on where the object is in space (both vision and postural location need to be trained separately) more peripherally the object is the more of a demand it requires. By the time the hand is at the object the hand aperture should automatically be at the right size for the object, also dependent on previous experience With visual problems you refer them on (won’t get a visual problem in exam so just say you’ve done a visual test and its fine). The role of postural component in reach and grasp ● Ability to move the arm(s) without destabilising the body. Postural activity is task and context specific you need to consider: the load (heavier= greater postural adjustment), how far to reach (i.e. trunk movements extend reach), speed (e.g. catch fast moving ball which needs increased postural stability) and If too far than must alter posture (e.g. sit to stand, or walk stand). Progression of the postural component is to go from a light to heavy load, stable base of support to a not so stable base of support (near to outer field) and slow to quick. Transport Phase Transport component (acceleration and deceleration) “reach and grasp” 1. Hand starts opening at the start of the transport phase 2. Fast, moves the hand to the vicinity of the object 3. Aperture increases throughout the acceleration phase 4. Aperture decreases during the deceleration phase 5. Distance between thumb and index finger reflects object size/shape (grip formation) 6. Trajectory determined by the relative position of the target & hand Once the hand contacts the object further guidance is provided by what? ● Transport phase should be a smooth arc of acceleration and deceleration. Acceleration is needed when the hand opens wider than needed, arm starts moving. While deceleration is more about fine tuning, hand closes closer to more accurate grip. When holding the object, you get proprioception and cutaneous feedback. The Speed you move on is dependent on the nature of the task/ the object you’re picking up. The longer the deceleration phase – smaller object as greater need for more accuracy, longer acceleration – something like pointing. There’s a need for assessing with multiple tasks and objects HAND GRIPS The size of maximal grip opening is proportional to the size of the object. The power grip Finger and thumb pads are directed towards the palm to direct force to an object. While the precision grip Forces are directed between the finger and thumb;

allows movement of the object relative to the hand & within the hand. Grasp is dependent on the purpose of the task for example holding an empty glass in comparison to holding a full glass. Midrange is when we usually pick something up (maximal cross bridge formation- when the muscle is at its strongest). Characteristic feature of both grips is WRIST EXTENSION & RADIAL DEVIATION ● Grip – ROM, strength, feedback (proprioception/ cutaneous) ● Manipulation - Translation (coins into a slot- from palm to fingers), 4. Stabilisation Phase Sustained isometric force is used to prevent object slippage. Grip force changes depend on the Load force/Weight, Surface texture, Pre-programming and Safety margin to prevent slippage. 5.Manipulation Component Movement of an object in space or with reference to another object. 1. Translation 2. Shift 3. Rotation 6. Release Component Should be released in a voluntary, controlled and safe manner. When assessing a patient's release component you need to see if the wrist remains in extended aperture or do they rely on compensatory mechanisms? Usually an issue with larger objects and common in neurological injury Lecture 3:- assessment of reach and grasp Process Assess vision and posture and observe performing R and G tasks (different size, weight, texture, fragility/deformity, location for different FUNCTIONAL tasks), from which you should be able to identify the problem or missing components. This will enable you to develop a hypothesis and perform additional testing to confirm or deny the hypothesis. Usually the problem is associated with sensation/ proprioception, strength, ROM, psychological etc. treatment

Outcome Measures •Grip strength: dynamometer •ROM-tracing, goniometer •Nine hole peg test-dexterity •Motor Activity Log (MAL): amount & quality of upper limb use •Manual Abilities Classification System (MACS) •Action Research Arm Test (ARAT) •Box and Block Test •Motor Assessment Scale (MAS) upper limb •Handwriting •Goal attainment scale (GAS)...