FM-hand

What happens with collateral ligaments during MCP abduction?

* RADIAL COLLATERAL LIGAMENT SLACKENS AND ULNAR COLLATERAL LIGAMENT BECOMES TAUT AS INTEROSSEI PULL

PIP/DIP joints have how many degrees of freedom? And which is the closed packed position?

1 degree of freedom= flexion/extension CLOSE PACKED POSITION: FULL EXTENSION (STRETCH OVER PALMAR PLATE)

FINGER MCP JOINTS HAVE How many DEGREES OF FREEDOM and what are they?

2 degrees of freedom and they are.... FLEXION/EXTENSION; ABDUCTION/ADDUCTION

MC 1 ROTATED ALMOST ___________ IN RELATION TO OTHER DIGITS

90 degrees

3 types of precision grips

A) LATERAL PINCH OR KEY PINCH: INDEX FINGER IS HELD IN SEMI-FLEXED POSITION AND THUMB PRESSURE IS APPLIED TO RADIAL SIDE OF INDEX B) THREE-PRONG CHUCK OR THREE-JAW CHUCK: PADS OF FINGERS 2-3 CONTACT PAD OF THE THUMB C) TIP-TO-TIP OR PINCER: THUMB FACES ONE OF THE FINGERS (USUALLY FOR SMALL OBJECTS)

4 power grips

A)HOOK GRIP: ONLY GRIP THAT DOESN'T REQUIRE USE OF THE THUMB B) CYLINDRICAL GRIP: THUMB DOESN'T TOUCH FINGERS; FINGERS & PALM ON ONE SIDE AND THUMB ON OTHER C) SPHERICAL GRIP: FINGERS ARE USUALLY MORE SPREAD OUT COMPARED TO CYLINDRICAL D) FIST GRIP: HAND ENCLOSES AROUND AN OBJECT; THUMB IS OFTEN IN CONTACT WITH OTHER DIGITS

What are the 2 degrees of freedom of the thumb?

DEGREES OF FREEDOM • ABDUCTION/ADDUCTION IN THE SAGITTAL PLANE AND FLEXION/EXTENSION IN THE FRONTAL PLANE • OPPOSITION AND REPOSITION ARE VARIANTS OF THE 2 CARDINAL PLANES (flex and ext)

PROXIMAL TRANSVERSE ARCH - Location and keystone

DISTAL ROW OF CARPAL BONES; FORMS THE CARPAL TUNNEL; RIGID • KEYSTONE= central portion

Extrinsic hand muscles (extensors and flexors)

DORSAL (EXTENSORS) • EXTENSOR DIGITORUM • EXTENSOR INDICIS • EXTENSOR DIGITI MINIMI • EXTENSOR POLLICIS LONGUS • EXTENSOR POLLICIS BREVIS • ABDUCTOR POLLICIS LONGUS • VOLAR (FLEXORS) • FLEXOR DIGITORUM SUPERFICIALIS • FLEXOR DIGITORUM PROFUNDUS • FLEXOR POLLICIS LONGUS

MC 1 ANATOMIC POSITION?

Dorsal surface of thumb faces laterally and palmar surface faces medially. Radial side is positioned anteriorly and ulnar side of thumb is positioned/faces posteriorly.

Extrinsic extensors of the digits and their actions (hint: there are 3)

EXTENSOR DIGITORUM - PRIMARY FINGER EXTENSOR (CAN ALSO EXTEND WRIST) • EXTENSOR INDICIS - EXTENDS INDEX FINGER WHEN OTHER FINGERS ARE FLEXED • EXTENSOR DIGITI MINIMI- EXTENDS ALL JOINTS OF LITTLE FINGER (OFTEN HAS 2 TENDONS)

Anatomical snuffbox muscles

EXTENSOR POLLICIS LONGUS EXTENSOR POLLICIS BREVIS ABDUCTOR POLLICIS BREVIS

Intrinsic and extrinsic Thumb muscles

EXTRINSIC = • FLEXOR POLLICIS LONGUS • EXTENSOR POLLICIS LONGUS • EXTENSOR POLLICIS BREVIS • ABDUCTOR POLLICIS BREVIS INTRINSIC = (THENAR) • OPPONENS POLLICIS • ABDUCTOR POLLICIS BREVIS • FLEXOR POLLICIS BREVIS

What is the SOLE FLEXOR OF DIP's?

FLEXOR DIGITORUM PROFUNDUS

Which muscles WORK SYNERGISTICALLY TO GRIP (CURL DIGITS + OPPOSITION OF DIGITS 1,4,5 CMC JOINTS)?

FLEXOR DIGITORUM SUPERFICIALIS FLEXOR DIGITORUM PROFUNDUS FLEXOR POLLICIS LONGUS

What is the SOLE FLEXOR OF THUMB IP?

FLEXOR POLLICIS LONGUS

What is the closed packed position for MCP joints?

Flexion (90 degrees)

Where do the RADIAL AND ULNAR COLLATERAL ligaments attach?

From the HEAD OF THE METACARPALS TO THE BASE OF THE PHALANGES

Closed packed position for thumb cmc joint

Full opposition

Trigger Finger

INFLAMED (ENLARGED) TENDON CREATES A NODULE SO THAT THE TENDON CANNOT GLIDE WITHIN THE SHEATH NODULE WILL SUDDENLY PASS THROUGH THE SMALL SPACE AND "SNAP" Tx: MODIFY ACTIVITIES, SPLINT, CORTISONE INJECTION, SURGICAL RELEASE (A1 PULLEY)

interrossei # of each, origin and insertion and action

INTEROSSEI - 3 PALMAR AND 4 DORSAL MUSCLES; ORIGINATE IN THE METACARPAL REGION OF THE HAND AND INSERT AT THE BASE OF THE PROXIMAL PHALANXES • PALMAR- ADDUCTION OF MCP • DORSAL- ABDUCTION OF MCP

What is the functional position and what is it used for?

It maintains the length of tissue to prevent contractions WRIST: 20-30 EXTENSION WITH SLIGHT ULNAR DEVIATION • FINGERS: 35-45 MCP FLEXION AND 15-30 PIP AND DIP FLEXION • THUMB: 35-45 CMC ABDUCTION

Lumbricals -attachments; insertions and actions

LUMBRICALS • NO BONY ATTACHMENT • PROXIMAL INSERTION- TENDONS OF FDP • DISTAL INSERTION -LATERAL BAND OF EXTENSOR MECHANISM • FLEX MCP JOINTS AND EXTEND THE IP JOINTS OF DIGITS 2-5 (PATH COURSES PLAMAR TO MCP JOINTS AND DORSAL TO PIP/DIP JOINTS)

Deep Palmer muscles include

Lumbricals and palmar and Dorsal interrossei

• DISTAL TRANSVERSE ARCH-location and keystone

MCP JOINTS • SIDES ARE MOBILE and 1,4,5 "FOLD" TO PROVIDE "CUPPING" • KEYSTONE= capitate

How will a median nerve injury will affect the thenar muscles?

MEDIAN NERVE INJURY • INNERVATION TO ALL THENAR MUSCLES = OPPOSITION IMPACTED • ADDUCTION CONTRACTURE

Extrinsic hand muscles (mid palm; thenar and hypothenar)

MID-PALM • FOUR LUMBRICALS • THREE PALMAR INTEROSSEI • FOUR DORSAL INTEROSSEI • THENAR • OPPONENS POLLICIS • ABDUCTOR POLLICIS BREVIS • ADDUCTOR POLLICIS BREVIS • FLEXOR POLLICIS BREVIS • HYPOTHENAR • OPPONENS DIGITI MINIMI • ABDUCTOR DIGITI MINIMI • FLEXOR DIGITI MINIMI BREVIS

Which muscles of the hand are innervated by the median nerve? And where does it provide sensation?

Median Nerve EXTRINSIC FLEXORS OF DIGITS (FDS, LATERAL HALF OF FDP & FPL), THENAR EMINENCE MUSCLES (FPB, ABPB, OP & LATERAL 2 LUMBRICALS) • SENSATION ON PALMAR LATERAL ASPECT OF HAND (LATERAL 3.5 DIGITS)

CMC opposition (phases)

PHASE 1: ABDUCTION OF THUMB METACARPAL • PHASE 2: FLEXION AND MEDIAL ROTATION (TOWARDS SMALL FINGER) • 45-60° MEDIAL ROTATION (EVIDENCED BY THUMB NAIL) • NOTE THAT DIGITS 4-5 ALSO CONTRIBUTE TO OPPOSITION BY CUPPING (BRINGING TIP CLOSER TO THUMB)

tenosynovitis

POOR TENDON GLIDING DUE TO REDUCE SPACE IN SHEATH AFTER SWELLING

2 categories of functional grasp

POWER GRIP: GROSS GRASP OF AN OBJECT USING THE ENTIRE HAND • THUMB IS IN ADDUCTION OR OPPOSITION PRECISION GRIP: PINCHING AN OBJECT BETWEEN THE THUMB AND FLEXOR SURFACE OF 1+ FINGERS FOR MANIPULATION OR USE • THUMB IS ABDUCTED

The flexor pulley system functions to

PREVENT BOWSTRINGING OF THE LONG FLEXORS DURING FLEXION ACTIVITIES

Where are the attachment points for intrinsic hand muscles?

PROXIMAL AND DISTAL ATTACHMENTS ARE WITHIN THE HAND

Where are the extrinsic attachment sites for the hand?

PROXIMAL ATTACHMENT IN THE FOREARM OR HUMERUS • DISTAL ATTACHMENTS IN THE HAND

LONGITUDINAL ARCH : locations of ends and keystone

PROXIMAL END = CMC JOINTS (STABLE) • DISTAL END = RAYS OF 2,3 (MOBILE) • KEYSTONE= other MP joints

2 types of proximal transverse arches

PROXIMAL TRANSVERSE ARCH and DISTAL TRANSVERSE ARCH

MCP JOINTS ARE SURROUNDED BY which pair of LIGAMENTS?

RADIAL AND ULNAR COLLATERAL ligaments

Which muscles of the hand are innervated by the radial nerve? And where does it provide sensation?

Radial nerve EXTRINSIC EXTENSOR MUSCLES OF DIGITS (ED, ED MINIMI, EI, EPL, EPB, ABPL) • SENSATION ON DORSAL ASPECT OF WRIST AND HAND

TENDON INJURY/REPAIR

TENDON GLIDING EXERCISES SUPPORT GLIDING OF TENDONS BETWEEN SHEATHS

How many degrees of freedom does the thumb MCP joint have?

THUMB MCP JOINT HAS ONE DEGREE OF FREEDOM (TYPICALLY CONSIDERED A HINGE JOINT) • FROM EXTENSION, ~60 FLEXION ACROSS THE PALM • EXTENSION - ONLY A FEW DEGREES And ABDUCTION/ADDUCTION are only ACCESSORY MOTIONs

What is the purpose of the PALMAR (VOLAR) PLATES and where do they attach?

They are ligament-like structures that stabilize and prevent hyper extension DISTAL END ATTACHES AT BASE OF PROXIMAL PHALANX • PROXIMAL END ATTACHES JUST PROXIMAL TO MC HEAD

What type of structure are the IP joints?

Tongue And Groove - 2 condyles with a valley between

Ulnar nerve injury will affect innervation to which types of muscles?

ULNAR NERVE INJURY - INNERVATION TO HYPOTHENAR MUSCLES

Which muscles of the hand are innervated by the ulnar nerve? And where does it provide sensation?

Ulnar nerve MEDIAL HALF OF FDP AND HYPOTHENAR MUSCLES (FD MIN, AB DIG MIN, OPPONENS DIG MIN, PALMARIS BREVIS & MEDIAL TWO LUMBRICALS & ALL INTEROSSEI & ADDUCTOR POLLICIS) • SENSATION ON ULNAR BORDER OF HAND (ULNAR 1.5 DIGITS)

TENODESIS ACTION occurs when.....

WHEN STRETCHING A POLYARTICULAR MUSCLE ACROSS ONE JOINT GENERATES PASSIVE MOVEMENT AT THE OTHER JOINT

Mechanisms of tenodesis

WRIST EXTENSION causes PASSIVE FINGER FLEXION (GRASP) • WRIST FLEXION causes PASSIVE FINGER EXTENSION (RELEASE)

When MCP joint is extended at 0 degrees,_______________________ ligaments are loose and _____________. ___________has elongated joint play

collateral ligaments are loose and palmar plate has elongated joint play