Functional Anatomy Exam 4

cubital fossa and volar forarm

elbow pit

carpal bones

scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate "Some Lovers Try Positions That They Can't Handle"

interosseous membrane of forearm

sheet of dense connective tissue that unites the radius and ulna bones

pronation muscles

pronator teres, pronator quadratus Pronator Teres Crosses the elbow Medial epicondyle of the humerus Lateral shaft of the radius, halfway down Pronator Quadratus Deep forearm muscle Lower anterior shafts of radius and ulna Stabilizes the position of the radius and ulna when falling onto outstretched arm More powerful; pronator teres only recruited for extra power

Arches of the hand

proximal transverse arch distal transverse arch longitudinal arch This information will be especially pertinent to your practice as an OT with regard to splinting The natural concavity of the hand allows grasp and manipulation of objects of various shapes and sizes

Power Grips & Precision Grips

"Power grips": cylindrical, hook, spherical Ex. holding tennis ball "Precision grips": 3 jaw chuck, tip, lateral (key) Ex. lacing sneakers

Joints of the hand

*Radiocarpal joint* (wrist joint) *Midcarpal joints* - between two rows of carpals *Intercarpal joints* *Metacarpophalangeal joints (MCP) *Proximal interphalangeal joints (PIP) *Distal interphalangeal joints (DIP) *Interphalangeal joint* (thumb)

hand manipulation

- Shift - Translation (fingers to palm) - Translation (palm to fingers) - Rotation (may be simple or complex depending on object's orientation)

Wrist extensors innervated by the radial nerve

-Extensor carpi radialis brevis (ECRB) -Extensor carpi radialis longus (ECRL) -Extensor carpi ulnaris (ECU)

Wrist flexors innervated by the median nerve

-Flexor carpi radialis (FCR)- flexion of wrist and radial deviation -Palmaris longus (PL)- flexion of wrist

Wrist flexors innervated by the ulnar nerve

-Flexor carpi ulnaris (FCU)

Hyperthenar Muscles

-Flexor digiti minimi -opponens digiti minimi -Abductor digiti minimi -Adductor digiti minimi all innervated by ulnar n.

Extrinsic flexors of the hand

-Flexor digitorum superficialis -Flexor digitorum profundus -Flexor pollicis longus Flexor Digitorum Superficialis •Origin: anterior forearm •Travels through the carpal tunnel and bifurcates •Insert on the middle phalanx of digits 2/3/4/5. •Flexes the PIPs. •Innervated by the Median n. Flexor Digitorum Profundus - deep to FDS •Origin: anterior forearm •Travels through the bifurcation •Inserts on the distal phalanx. •The FDP flexes both DIP and PIPs (primary function can be considered DIP flexion) •FDP to digits 2/3 is Median n. innervated •FDP to digits 4/5 is Ulnar n. innervated Flexor Pollicis Longus •Originates on the radius and interosseous membrane •Inserts on the distal phalanx of the thumb. •Flexes the thumb •Innervated by the Median n.

Volar hand intrinsic muscles

-lumbricals -palmar interossei The Lumbricals (Latin - lumbricus (worm) are the only muscles in the body that originate and insert on soft tissue. The 4 muscles each originate off a slip of the FDP and insert on the extensor mechanism of the same digit. Flex the MCP and extend the IP . Lumbrical 1 and 2 = Median n. Lumbrical 3 and 4 = Ulnar n. Paralysis leads to clawing of the fingers The Palmar Interossei - 3 small muscles originate on the shaft of the metacarpals (ulnarly on 2, radially on 4, 5) insert on the extensor mechanism. Primarily adduct digits (toward the long finger) - accessory IP extenders and MCP flexors. Ulnar n. innervated

Forearm Movements

Anatomical position: ulna and radius are parallel Pronation: radius crosses/rotates over the ulna to turn the hand downward Supination: ulna and radius are parallel again. Supinators are stronger (screws have right handed thread) Midprone/Neutral: functional position of the hand

Development of fine motor skills as related to normal body development

Base of support development required for fine motor and prehension skills to develop Prehension is defined as the application of functionally effective forces by the hand to an object for a task, given numerous constraint tummy time -->crawling develops arm and sholder muscles for example.... prereaching, ulnar grasp, pincer grasp

Bones of the hand

Central axis of the hand - 3rd metacarpal MCPs •synovial ellipsoid, biaxial joints -Flex/ext and ab/adduct •IF,LF,RF,SF stabilized by sagittal bands •Thumb has a sesamoid bone at volar MCP - acts like a pulley for he FPL • • IPs •synovial hinge joints - Flex/ext only •stabilized by radial and ulnar collateral ligaments •Volar IP joints have volar plate •Dorsal IP joints have dorsal hood The metacarpal combined with the phalanges is sometimes referred to as a ray Bones of the hand - each bone has a base, a shaft, a neck, and a head MCPs, PIPs enclosed in joint capsule

movements of digits 2-5

Digits 2-5: •Flex, ext, ab/add movements occur at the index, long, ring, and small fingers. •CMC joint- bases of metacarpals to trapezoid, capitate, hamate. •AB/AD only occurs at the MCPs. •Adduction of the MCPs is fairly compulsory when the joints flex, due to ligamentous attachments •Flexion/Extension at IPs

Factors that may affect motor development

Disruption of sensory, cognitive, socio-emotional, language development, cultural norms

forearm extensors

Extensor carpi ulnaris, extensor carpi radialis brevis, extensor carpi radialis longus Extensors - lateral epicondyle, superficial posterior forearm ECU - metacarpal 5 ECRB - metacarpal 3 ECRL - metacarpal 2 (origin is ridge proximal to lateral epicondyle with brachioradialis) Act as synergists to counteract flexion by long finger flexors during gripping Hold hand up vs gravity during functional tasks with hand prontated

muscles that open the hand

Extrinsic Extensor Digitorum Extensor Digiti Minimi Extensor Indicis Extrinsic that move thumb: Abductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus

Aging considerations for treatment progressions

Increase in degenerative diseases Physiological decline in body systems Musculoskeletal: skin, muscle/neuromuscular, sensibility/sensation. Cognition, vision Epithelial cells Decrease in fibroblasts = decrease collagen production Re-ep. And would contraction slower Less reproduction of ep. Cells Lose fat/thinner cells, more suscept. To injury Connective tissue: decrease resistance to tensile forces and reduced resiliency Elastin changes = decrease tissue elasticity Skin: altered wound healing metabolism and remodeling of collagen Dryness Increase incidence of skin tears Muscles tissue: decreased density and strength Lean body mass decreases Lipofuscin (age related pigment) and fat deposited in muscle tissue Muscle tissue replaced more slowly, may be replaced with tough fibrous tissue Musculoskeletal structural changes Decrease in motor neurons, muscle fibers/strength/mass Hand atrophy: interosseous and thenar muscles Cartilage Osteoarthritis: depletion in cartilage around joint surfaces -- bone on bone Skeletal changes Osteoporosis: decrease in bone density Decrease joint RoM Postural changes: kyphosis

common pathology of wrist

Pain is often felt in forearm since that is where the muscles are located wrist fractures = FOOSH tennis and elbow golfers elbow Colles' fracture: lower broken ends of bone are displaced backwards Smith's fracture: only the radius is fractured and the distal fragment displaced forwards A fall on the hand with the wrist in full extension may fracture the scaphoid the scaphoid fractures across its waste, and the proximal fragment may die due to poor blood supply → this avascular necrosis may produce persistent pain & weakness of the wrist

Carpal tunnel assessment

Phalen's test, semmes weinstein, thumb opposition, Tinel's, rule out other possible causes

Forearm Joints

Proximal/Superior Radioulnar Joint: head of the radius and radial notch of the ulna Lies inside the capsule of the elbow joint Movements are independent of the elbow joint Annular ligament surrounds the head of the radius and attaches firmly to the radial notch Distal/Inferior Radioulnar Joint: head of the ulna Disc of fibrocartilage holds head of ulna to distal radius Joins the styloid process of the ulna to the ulnar notch of the radius Thin, loose capsule Bones held together by interosseus membrane and disc

Nerve recovery general principles

Sensory comes before motor Good blood flow/nutrition promotes healing 4 weeks after nerve injury: nerve tries to re-establish balance (wallerian degeneration) Recovery is slow and inconsistent (starts and stops); sensitive to environmental changes Nerve irritation does not always respond immediately

finger pulley system

The FDS, FDP and FPL travel through a synovial sheath in the proximal palm They exit the sheath then enter individual tendon sheaths that travel the length of each digit The sheaths are reinforced with a series of ligaments called pulleys. (5 annular and 3 cruciate ) Pulleys are like the rings on a fishing rod. They create mechanical advantage, keeping the tendon close to the bone to prevent bowstringing.. A2 and A4 are particularly important for this The thumb has 3 pulley of it's own. Tendons in the sheath are particularly challenging for rehabilitation when cut.

carpal tunnel syndrome

The carpal consists of a semicircle of carpal bones dorsally and the transverse carpal ligament volarly. 9 tendons and a nerve pass through a channel the diameter of a nickel. Compression due to fluid retention (pregnancy) repetitive motions, posturing, fracture Numbness/tingling to median distribution, positive Tinel's sign, muscle pain and atrophy. Treatment: splint wrist, patient education, surgical release

Tennis elbow (lateral epicondylitis)

The extensor muscles of the forearm attach to the lateral epicondyle of humerus Overuse or trauma

flexor tendon sheaths

These sheaths help to constrain the long flexor tendons of the toes to prevent bowstringing

arthritic changes in the hands

Zig-zag deformity Ulnar drift (fingers lean to ulnar side) -- normal but more pronounced in Older generation nodules swan neck deformity =hyperextension of PIP, flexion of DIP boutonniere= flexion of PIP, hyperextension of DIP

Flexor Tendon Zones

Zone I: extends from fingertip to the center portion of the middle phalanx Zone II: extends from the center portion of the middle phalanx to the distal palmar crease (known as no man's land due to difficulty of tendon gliding without scarring to surrounding tissues) Zone III: extends from the distal palmar crease to the transverse carpal ligament Zone IV: overlies the transverse carpal ligament Zone V: extends beyond the level of the wrist

extrinsic extensor of thumb

abductor pillicis longus extensor pollicis longus extensor pollicis brevis Three extrinsics go to the thumb- Abductor Pollicis Longus, Extensor Pollicis Longus, Extensor Pollicis Brevis. All are Radial n. innervated Form the anatomical snuffbox

thenar muscles

abductor pollicis brevis, flexor pollicis brevis, opponens pollicis Thenar Muscles: act on the thumb - for all intents and purposes have a common origin and nerve •Abductor Pollicis Brevis- most superficial- can palpate with palmar abduction •Flexor retinaculum •Base of prox phalanx of thumb •Median n. •Flexor Pollicis Brevis- •Flexor retinaculum •Base of the prox phalanx of thumb •Flexes the MCP •Median n •Opponens Pollicis- •Flexor retinaculum •1st metacarpal •Rotates for opposition •Median n

dorsal interossei action

abducts fingers 2-5; flexes MP joints 2-5, and extends PIP and DIP joints

pronation and supination of forearm

actions of radio-ulnar joint Supination: the radius and ulna are parallel 1.Supinator (Radial Nerve)- deep mm., involved in all slow unopposed movements of supination 2.Biceps Brachi (Musculocutaneous Nerve) i- makes all supination movements requiring resistance ● Pronation: the radius and ulna are crossed 1.Pronator Quadratus (Median Nerve)- deepest forearm mm, transverse fibers, during FOOSH keeps the radius and ulna from separating, recruited for all unresisted pronation movements 2.Pronator Teres-(Median Nerve) stronger pronator when resistance is needed

midcarpal joint

articulation between the two parallel rows of carpal bones Distal surfaces of scaphoid, lunate, triquetral Proximal surfaces of trapezium, trapezoid, capitate, hamate Capsule of radiocarpal joint extends to cover midcarpal joint Both joints are strengthen by ulnar and radial collateral ligaments Midcarpal joint contributes most to flexion and radial deviation

Supination muscles

biceps brachii, supinator Biceps Brachii Superior glenoid cavity and coracoid process Radial tubersosity Supinator: Deep posterior muscle Lateral epicondyle of humerus and adjacent ulna Fibers wrap around proximal end of radius Insert into proximal end of shaft of radius

Extrinsic extensor muscles of the hand innervated by the radial nerve

extensor digitorum (communus) extensor digiti minimi extensor indicis

Movements of the thumb

flexion, extension, abduction, adduction, opposition Thumb •Thumb CMC articulates with the trapezium •Saddle joint allowing movement in 2 planes (basal joint) •Flexion/Extension •Abduction/adduction •Some rotation (medial rotation for opposition) •Significant for OA •MCP and IP are hinges that flex and extend

Abductors (Radial Deviators) of the Wrist

flexor carpi radialis, extensor carpi radialis longus

flexor muscles of forearm

flexor carpi ulnaris, flexor carpi radialis, palmaris longus Flexors - medial epicondyle, superficial, anterior forearm FCU - pisiform and base of 5th metacarpal FCR - base of metacarpals 2 and 3 PL - absent in 15% of people; palmar aponeurosis

Adductors (Ulnar Deviators) of the Wrist

flexor carpi ulnaris, extensor carpi ulnaris

Golfer's elbow (medial epicondylitis)

from repetitive strain of wrist flexors - not always from golf

grip develops from _____ to _____ side of the hand the forerarm goes from ____ to _______ movements body goes from _____ to _____ control

from the ulnar to radial side of hand, palmar to radial pronation to supination proximal to distal control

palmar aponeurosis

insertion of palmaris longus •Triangular sheet of fibrous tissue covering all the tendons of the palm •Flexor retinaculum to base of fingers •Anchored to the metacarpals and the deep transverse palmar ligament

Flexor retinaculum (transverse carpal ligament)

ligament crosses the wrist from the pisiform/hook of hamate to trapezium/scaphoid; what is cut during carpal tunnel release

predictive factors of nerve recovery

nature of the lesion - Neuropraxia, Axonotmesis, Neurotmesis Site of leision Nerve itsself Health of Surrounding Tissue Age of pt vitality of muscle and jt

radiocarpal joint

pertaining to the joint between the radius and wrist Concave distal end of radius and articular disc over the ulna Convex surface formed by 3 carpals (scaphoid, lunate, triquetral) Ellipsoid joint: movement in 2 directions (flexion and deviation) Radiocarpal joint contributes most to extension and ulnar deviation

when radial deviator and ulnar deviators all fire wrist is ____________.

stabilized (necessary for power gripping and to overcome ligamentous instability at the wrist)

carpus

the eight carpal bones of the wrist Carpal bones collectively called the carpus. 8 bones, in 2 rows of 4

Ligaments of the wrist

•Ulnar collateral ligament •Radial collateral ligament •Triangular Fibrocartilage Complex •Scapholunate ligament •Luno-triquetral ligament •Transverse Carpal Ligament

Sensory changes with aging

vision: increased blurring, decreased night vision Macular degeneration: blurred central vision Cataracts: general blurry vision Diabetic retinopathy: "swiss cheese" vision hearing: decreased hearing ability over time, increased problems with balance, less able to decipher background and foreground noises taste and smell: decreased ability to taste and smell Tactile: touch/pressure threshold requires stronger input, acuity decreases Nervous tissue: brain/spinal cord lose nerve cells and weight Nerve cells transmit messages more slowly Waste products collected in brain tissue (plaque) Mental structures: brain changes: reduced mass Cognitive decline Processing speed STM Abnormal pathology: dementia, alzheimers, delirium Neuromuscular: sensory perception, central processing, speed based psychomotor (tremors)

muscles that close the hand

•Extrinsic -Flexor Digitorum Superficialis -Flexor Digitorum Profundus -Flexor Pollicis Longus

Ligaments of the hand

•MCs •The metacarpals have strong proximal and distal ligaments to stabilize . •Deep transverse ligament holds the MC heads together to form the palm of the hand. •IPs •Each IP joint is contained in a capsule, with radial and ulnar collateral ligaments laterally and a volar plate on the palmar side. •The volar plate is a strong stabilizer that restricts hyperextension of the joint- but is prone to tears and contractures. •The collateral ligaments of all the IPs are prone to shortening (referred to as a contracture) , which puts the joint in a flexed position and it can not be passively extended. Dislocation = stretch or tear of these structures- can lead to deformities UCL of the thumb MCP is particularly prone to injury= Gamekeepers Thumb