1. locating the target - requiring coordination of eye and head movements

2. reaching - involving transportation of the arm and hand as well as postural support

3. grasp including grip formation - grasp and release of the object

4. hand manipulation of the object

1. constraints of individual - due impairments resulting from injury

2. requirement of specific task

3. environmental elements affecting task performance

to reach for an object it must first be located - the eyes move first to locate the object, followed by head turning if necessary.

consider the postural control that may be needed to accomplish this initial phase because some pts may have difficulty locating the object

reaching for an object can be divided into two subcomponents

1. reach

2. grasp

dependent upon the characteristics of the task

sensory system provides info about task such as where it is located

info processed during the task to modify and correct the mvmt

Reach and Grasp:

Visual information

Imput goes from visual cortex to temporal cortex to identify WHAT the object is

Also goes from visual cortex to parietal lobe to ID WHERE the object is located including position and orientation which allows the plane to be generated to reach and grasp for the object = feedforward control

during mvmt cerebellum updates mvmt pattern using incoming sensory info = feedback control

for error detection and correction

Reach and Grasp

Somatosensory Info

fine regulation of mvmt

during reaching and control of grip forces

reaching jt receptors, mechanoreceptors, muscle spindles are active in controlling mvmt

simple non-repetitive mvmts can be performed WITHOUT somatosensory info

thus you do not have to feel in order to perform UE reaching

Graspsing = cutaneous receptors relay info to modify the grip based on characteristics of the object such as slippery surface or delicate object

** VISUAL FEEDBACK IS MOST CRITICAL**

Musculoskeletal requirements for UE

function

vary according to reaching task

when postural demands are reduced such as sitting with support - speed of mvmt can increase

Grasping

2 important requirements

1. hand must be adapted to shape, size and use of the object

2. finger mvmts must be timed so that they close around the object at the appropriate moment

Intrinsic Properties

of object size that affect pre_grasp hand

shaping

Extrinsic Properties

of an object that affect

pre-grasp hand shaping

include hook grasp (suitcase handle)

spherical grasp (baseball)

allows mvmt of object relative to the hand

and power grips DO NOT do that

Grasp lift tasks

4 phases

1. lift starts with contact btwn fingers and the object to be lifted
2. grip force and the load force (load on the fingers) increasing
3. begins when the load force overcomes the load of the object and it starts to move
4. occurs at the end of the lifting task when there is a decrease in the grip and the load force after the object makes contact with the table

while the hand is transported towards the object the fingers are preshaped to grasp the object -

these components (reach and grasp) are functionally coordinated together

neurologic impairments will likely result in deviations of both reach and grasp

They must be trained both separately and together in varying functional contexts

when arm mvmt precision is increased or mvmt distance is increased mvmt time is longer

mvmt time increases linearly with task difficulty

Temporal interdependence

or temporal assimilation

examining by manual control investigative mvmt time and trajectory path to a target

both arms move to targets of identical size and distance

one arm had to move over a card board hurdle - mvmt time increased in the hurdle arm, BUT

mvmt time also increased in the arm that did NOT have a hurdle

with hurdle - arm negotiating hurdle had an increased mvmt trajectory as did the limb without the hurdle

so

one extremity is assimilating to be like the other extremity thus FITTS' law is not upheld in bi-manual aiming tasks

limbs like to time mvmts together either in phase or out of phase

Ex: alternatively tap first finger to thumb on each hand, notice how you move rythmically and incontact and same distance - speed up the mvmt

involves eye movement, eye and head, or eye head and trunk. several impairments can impair one's ability to locate an object.

(ie damage to occulomotor system causing disturbance in eye control

disruption of the vestibular occular reflex making it difficult to control eye and head mvmts.

Damage to cerebellum may affect the ability of the VOR to the task = homonymous hemianopsia

Motor Problems

name 4

(reach and grasp)

1. timing
2. interjoint coordination
3. spasticity
4. other motor problems

Motor problems

Timing

Motor problems

interjoint coordination

Cerebellar damage may result in mvmt

decomposition (moving one jt at a time)

under or over shooting a target

mvmt may become slow to increase mvmt accuracy or compensate for poor control

Motor problems

Spasticity

extent to which spasticity limits UE function is unclear - weakness may be more limiting

fast mvmts may elicit and inappropriate activation of the stretch relfex and therefore limit arm mvmt

Motor problems

Other problems

(i know stupid heading)

Sensory Problems

(reach and grasp)

Name the 2

1. vision
2. somatosensation

Sensory problems

Vision

Sensory Problems

Somatosensation

not necessary for mvmt initiation and execution

however

important for accurate reaching involving multiple jts

Grip manipulation and release problems

name the 2

Grip, manipulation and release

Motor

neurologic injury can affect the activation, coordination and force generation during lifting and gripping an object

damage to the descending corticospinal tracts will lead to weakness and altered m activation

Grip, manipulation and release

Sensory

somatosensory loss = difficulty regulating forces for grasp due to the loss of sensory feedback

lesions of the post parietal area affect the ability to shape the hand according to the objects size and configuration

it is suggested that this cortical area integrates visual and motor signals related to object orientation

Examination of UE

reach and grasp

key components of UE control

strategy

all 6 of em

1. eye-head coordination
2. postural control
3. arm and hand transport
4. grasp and release of object
5. manipulation of object
6. bi-manual control

key components of UE control

strategy

eye-head coordination

key components of UE control

strategy

postural control

key components of UE control

strategy

arm and hand transport

key components of UE control

strategy

grasp and release of the object

examine object place in different locations and in varying orientations

look at ability to release objects and place objects at different speeds with varying degrees of accuracy

key components of UE control

strategy

manipulation of the object

examine manipulation, control and use of an object to accomplish functional tasks

for example: examine manipulation of a fork, pen, or hairbrush all are grasped and manipulated differently based on the requirements of the task

key components of UE control

strategy

bi-manual control

examine tasks that utilized symmetric and asymmetric mvmt patterns

examine mvmt of both limbs and interaction btwn the two UEs

Common disorders affecting

shoulder function

5

1. normal osteokinematics
2. shoulder disfunction - altered scapulohumeral rhythm
3. shoulder disfunction - subluxation
4. shoulder disfunction - painful shldr
5. examination and intervention of shldr disfunction

normal orientation of the scapula and GH fossa is ant/lat/and upward facing

mm = serratus ant & trap work to keep the scapula aligned to the rib cage

mm = surrounding the GH jt supply support and stability

Normal osteokinematics

A. motions of the scapula

B. motions of the GH jt

A. abd/add, elevation/depression, protraction/retraction, upward/downward rotation

B. flx/ext, abd/add, IR/ER, horizontal abd/add

persons with neurological injury have problems with jt alignment and muscle activation thus they are susceptible to impingement, pain and subluxation

Shoulder disfunction

altered scapulohumeral rhythm

normal = 1:2, one degree of scapular motion for two degrees of humeral motion

scapular motion beginning after 60degrees of humeral motion

first phase of scapular mvmt 0 - 90 is scap elevation and upward rotation of scap

2nd phase = 90 - 120 increased scap rotation

intrinsic and extrinsic causes

Intrinsic = trunk/jt malalignment, imbalance of mm activation, weakness, abnormality of tone, soft tissue extensibility

Extrinsic = positioning, handling, assistive devices

3 types of subluxation can occur

name them

1. inferior - most common
2. anterior
3. superior

humeral head below inferior lip of GH fossa

with humerus in IR

scapula depressed and downwardly rotated with inferior angle of scap winging

Causes = loss of scap stability of rib, loss of trunk control, scap mm weakness, flaccid paralysis of UE

Shoulder disfunction -

painful shoulder

typical pattern - pt initially complains of sharp pain and end of mvmt when arm is moved passively

if causative factors are not eliminated pain will increase until limb is painful with all mvmts particularly with elevation of abduction of shldr -

pain may also be present at rest/in bed

in late stages pt may find it difficult to give exact location of pain and indicate deltoid area by rubbing over the muscle

Pts with shoulder pain may experience

these 5 things

1. difficulty concentrating on learning new skills
2. difficulty regaining independence in ADLs secondary to pain and stiffness
3. delayed or absent balance reactions - fear of moving the arm
4. lowered moral and depression
5. inhibited mms activity making it more difficult to stimulate recovery of the involved UE

Regional pain syndrome

or reflex and sympathetic dystrophy

Causative factors of

shoulder pain

3

1. loss of scapulohumeral rhythm
2. inadequate ER of humerus
3. lack of downward gliding mvmt of head of humerus in glenoid fossa

Activities which frequently cause trauma and lead to shoulder pain

4

1. PROM of GH jt without adequate scapular motion
2. Assisting the pt with transfers by pulling on the arm
3. Lifting the pt back into the wheelchair by lifting under the axilla
4. lifting the arm up from the hand only during ADLs without ensuring scapular rotation

Exam and intervention for shoulder disfunction

EXAM

1. trunk posture statically and dynamically
2. scapular and humeral position
3. scapular and humeral mobility
4. scapulohumeral rhythm
5. musculoskeletal impairments limiting mvmt

Prevention and treatment of

shoulder subluxation and pain

early intervention is important, early goals directed at maintaining alignment and preventing development of soft tissue restrictions and other secondary (indirect) impairments

** pt education is key**