locomotion lecture

VET30370

what is physical therapy?

the treatment of physical dysfunction/injury by the use of therapeutic exercise & the application of modalities, intended to restore/facilitate normal function/development

why is physical therapy necessary?

• missing link in veterinary care for a long time

• well recognized profession in the medical field

• benefits in animals only recognized in recent times

• area where vets & nurses can play a large role

  • carrying it out themselves on inpatient

  • educating owners when patient is discharged

• should only be carried out under the direction of the vet and the physical therapist in charge of the case

why choose physical therapy?

• concentrates in rehabilitation of the musculoskeletal system & nervous system

• evidence based benefits

• techniques based on physiological principles

benefits of PT

• improve circulation

• relax muscle spasm

• prevent & relax of muscle contracture

• dispersal of edema in muscle, joints, soft tissue

• mobilize of adherent tissues

• restore/maintain normal ROM in joints/limbs

• contributes to analgesia (decrease muscle spasm & edema)

• more comfortable & confident patient

• quicker return to normal activity

• neuromuscular re-education

what method is used for PT?

• symptoms + precautions + prognosis + further contributing factors → hypothesis & working diagnosis

• clinical reasoning

• knowledge of:

  • anatomy & physiology

  • biomechanics

  • conditions

  • diseases

  • animal behavior

skeletal muscle functions

• producing body movement

• stabilizing body positions

• storing & moving substances within the body

• generating heat

skeletal muscle tissue

• 40% of total BW (640 muscles)

• largest cells in the body & bound with connective tissue

• abilities:

  • contractility

  • excitability

  • extensibility

  • elasticity

connective tissue

• surrounds & protects muscular tissue

• separates muscle from skin

• provides pathway for nerves, blood vessels, and lymphatic vessels to enter and exit muscles

• composed of:

  • areolar tissue- store fibroblasts & collagen

  • adipose tissue- stores triglycerides, insulates, reduces heat loss, protects muscles from trauma

fascia

• dense sheet/broad band of dense irregular connective tissue that lines the body wall and limbs

• support & surrounds muscles and all other organs in the body

• functions:

  • hold muscles with similar functions together

  • allows free movement of muscles

  • carries nerves, blood vessels, and lymphatic vessels

  • fills space between muscles

  • all 3 connective tissue elements connect to structures (bone/other muscle) and may form tendon

    • epimysium, perimysium, endomysium

types of NS receptors

• chemoreceptors

• photoreceptors

• thermoreceptors

• mechanoreceptors

mechanoreceptors

sense change in joint movement, muscle tension, muscle length

feed info to CNS to respond by muscle contraction or inhibition

muscle spindles

small, elongated structures scattered among/arranged parallel to contractile extrafusal muscle fiber

respond to muscle stretch

responsible for muscle tone

rehab appilcations

• repetitive & assisted exercises

• massage

• increase load of exercises

• increase resistance

• stretches to increase muscle tone

• early mobilization

• PROM & AROM

• proprioception rehabilitation

  • body's ability to sense its location, movements, and actions in space without conscious thought

joint receptors

found in the capsule & ligaments around joints

stimulated by mechanical distortion that accompanies changes in the relative positioning of bones linked by flexible joints

movement

requires proper timing so antagonistic & synergistic muscle groups contract in the appropriate sequence and to the appropriate level

types of movement

• reflex movement

• postural reflexes

• voluntary movement

• rhythmic movement

reflex movements

• least complex

• integrated primarily in the spinal cord

• stretch & reciprocal inhibition- control movement around the joint

• flexion- pull limbs away from painful stimuli

postural reflexes

• integrated in the brainstem

• require continuous sensory input from visual & vestibular sensory systems

voluntary movements

• most complex

• integrated at cerebral cortex

• initiated at will without external stimuli

rhythmic movement

• combination of reflex & voluntary movements

• initiated & terminated by input of cerebral cortex

• once initiated can be sustiained without further input from the brain

golgi tendon organ

• responds to muscle tension

• found at the junction of tendons & muscle fibers

• respond to the tension a muscle develops during an isometric contraction

  • cause relaxation reflex

methods of hydrotherapy

• manual therapy (massage)

• therapeutic exercise

• hydrotherapy

• thermotherapy

• electrotherapy

manual therapy

• breaks vicious circle of pain & muscle tension

• increase blood flow

  • improves oxygenation to tissue & aids metabolic waste removal

• improves venous & lymphatic return

• breaks down & mobilizes adhesions

• releases natural endorphins

  • provides pain relief

  • improves cutaneous perception in neurological patients

  • accelerates muscle recovery

  • promotes mental & physical relaxation

  • improves pet-owner bonding

cons to manual therapy

• local inflammatory process

• systemic/ local infection

• neoplasia

• hyperthermia

• coagulopathy

• bruising

• cardiac compensation

• 48hrs post acute injury

• disloaction/fracture/severe instability

• edema of unknown origin

types of therapeutic exercies

• passive range of motion (PROM)

• stretching

• assisted exercise

• active assisted exercise

passive range of motion

• helps contain muscle atrophy

• prevents adhesions

• improves proprioception

• reduces stiffness from inactivity

  • stretching shrunken joint capsules, ligaments, tendons

• should be carried out after massage & heat application

cons to PROM

• joint dislocation

• fractures involving joints

• osteosarcoma

• joint with restricted movement following trauma

stretching

• can be combined with PROM

• stretch & realign soft tissue structures without tearing them

• when the joint has reached the end of range during PROM repitiotion

• never stretch beyond the patients comfort level

• 2-3 reps 1-3x day

assisted exercise

• bridge the gap between passive & active exercise

• enhance strength & endurance

• enhances proprioceptive training and prepares for more active exercise

• gradually increase he length of each session as the patient gets stronger

• 10-15 reps 2-3x day

how to deliver assisted exercise

• position patient with feet squarely underneath body

• support the patient in this position using a towel/sling

  • allow them to bear as much weight as possible

• as patient weakens gently reposition them

active assisted exercise

• slow walks

• weight shifting

• withdrawal reflex

• stair climbing/inclines

• sit-stand exercises

• wheel barrowing

• pole weaving

• cavatelli rails

• dancing

hydrotherapy

the use of water to relieve discomfort and promote physical well-being

allows unloading of painful joints

early weight bearing on very weak or painful limbs

benefits to hydrotherapy

• musculoskeletal system

  • muscle

  • joint

  • ligament

  • tendons

  • bones

• cardiovascular system

  • circulation

  • edema

• nervous system

  • proprioception

  • well being

cons of hydrotherapy

• open & infected wounds

• unhealed surgical incisions

• surgical incisions without waterproof cover

• fever

• systemic compromise

  • cardiac/ liver/ kidney disease, hypertension, severe hypotension

• respiratory compormise/distress

• edema of unknown origin

• advance debility

• uncontrolled epilepsia

• infectious disease

hydrotherapy precautions

• fecal/urinary incontinence

• older age patients

• mild systemic compromised

• extremely obese patients

• external fixator

• skin/ear/vestibular problems

• epileptic

thermotherapy

use of physical agents/means to heat/cool the body

• superficial heat

• cryotherapy

superficial heat therapy

• cause vasodilation to increase blood flow

• reduce muscle spasm

• increase tissue stretching ability

• only effective is tissue temp raised by minimum 3ºC

  • harmful is raised above 45ºC

  • rapidly decreases once heat is removed to stretching & PROM should be done during or right after

• 15-20 mins 2-3x day

indications for heat therapy

• chronic arthritis

• muscle tightness/tension

• in preparation for exercise

• to warm muscle prior to stretching/ ROM

• start 2-3 days post-op

cons for heat therapy

• acute inflammation

• bleeding disorders

• open wounds

• acute injuries

cryotherapy

• vasoconstriction of blood vessels to decrease blood flow

• reduce swelling

• temporary pain relief

• reduce muscle spasm

• increase proprioception by increasing nerve impulse speed

• decrease cellular metabolism

  • reduce tissue activity and the need for oxygen

  • allow cells to remain viable in reduced oxygen environment

• induce hunting’s response if left for >20 mins

  • reflex dilation of deep arteries to cause increased blood flow to area

  • aid in natural debridement

• 15 mins 3-4x day

indications for cryotherapy

• arthritis (+ acute flare up)

• acute trauma

• post-op pain relief in first 2-3 days

• post exercise inflammation

cons to cryotherapy

• hypersensitivity to cold

• circulatory problems

• near open wounds

• care with metal prothesis

tissue healing phases

1. acute phase

2. tissue formation

3. remodeling

phase 1- acute phase

1. early (acute)- inflammatory response lasting 2-4 days

   • PRICE= protection, rest, ice, compression, elevation

   • manage initial swelling & pain

2. late (sub-acute)- continue inflammatory phase which is usually complete in 2 weeks

phase 2- tissue formation

• tissue rebuilding 2-3 weeks (does not include chronic inflammation)

• as pain decreases add:

  • cardiorespiratory fitness

  • increase ROM

  • restore/increase strength

  • re-establish neuromuscular control

  • continued use of modalities for pain control

phase 3- remodeling phase

• adapt to original tissue & continues up to 1 yr post injury

• continued collagen realignment

conformation

physical appearance & outline of a horse as dictated primarily by bone & muscle structures

• varies according to purpose for which the horse is intended

• poor conformation is not unsoundness but it can lead to lameness

• good conformation does not guarantee good performance

soundness

horse is free of lameness & is suitable for a particular purpose

blemishes

scars/irregularities that do not affect the serviceability of the horse

unsoundness

causes a horse to be lame or otherwise unservicable

contributions to conformation

• dam may contribute more to faults that sire

  • stallions are proven performers with exceptionally good conformation

  • fillies with faulty conformation may be retired from breeding if they develop lameness

• heritable conditions

  • toeing in/out

  • back at the knee

  • offset kneee

  • tied in below the knee

  • sickle hock

  • straight behind

conformation analysis

• balance

• assessment of lengths, angles, heights

• muscling

• limb conformation

balance

• relationship between:

  • forehand and hindquarter

    • short back- may have shorter strides

    • long back- may have trouble engaging hind limbs

  • limbs & body

  • left & right halves

• body length (shoulders to tuber ischii) = withers height

• withers height = rump height

horse divisions

• front= muzzle to girth

• middle= girth to rear flank

• hind= rear flank to tuber ischii

center of gravity

located at the intersection of

• vertical line dropped from the highest point of the withers

• horizontal line drawn from the point of the shoulder to tuber ischii

length, angles, heights

• shoulder length & angle

  • related to stride length

    • long shoulders- long strides

    • short shoulders- short strides

  • line from scapula should be at same angle as pasterns (45º)

• upright pasterns

  • shorter angle = shorter strides

what produces long strides?

• long shoulders

• long radius & short metacarpus

• long gaskin (mind limb muscles between stifle & hock) & short metatarsus

• flat & long rump

what predisposes hindlimb lameness?

short, steep rumps

what predisposes forelimb lameness?

taller behind than in front

forelimb conformation faults from upright pasterns

• increases concussion on fetlock, phalangeal joints, navicular apparatus

• affected horses are prone to navicular disease & ringbone

• risk of fetlock effusion increases with increased dorsal hoof angle

forelimb conformation faults from long/sloping pasterns

• injury of flexor tendons, sesamoid bones, suspensory ligament

• osteoarthritis of fetlock

• P1 fractures

muscling

• muscles add support to skeleton & joints

• length, thickness, distribution of each muscle group vary with age & sport activity

• symmetry

limb conformation from front/rear

• a line dropped from the shoulder/tuber ischii should divided the leg into 2 symmetrical halves

• observe 2 characteristics

  • base- wide or narrow

  • limb axis- straight, turned outwards, turned inwards

wide base

inside foot weight bearing

narrow base

outside foot weight bearing

toed out

• (splay footed)

• plaiting- in flight toes swing inward

• results in abnormal wear on inside of foot

• predisposes horse to medial splints

• slight toe out may be desirable (decreased risk of carpal fracture)

toed in

• (pigeon toed)

• paddling- toes swing outward

out at the knee

• bow legged

• most affected horses are also toes in

• predisposes to osteoarthritis of carpus/fetlock

• predisposes to lateral suspensory branch desmitis & sesamoiditis

in at the knee

may predispose to splints

bench/offset knees

• metacarpal 3 offset

• medial aspect of joint bears abnormal weight

• joint is no longer balanced

angular limb deformity (ALD)

• deviation of the limb from its normal axis in the frontal plane

• most common in the carpus but also seen in fetlock & tarsus

• valgus or varus

• usually some rotational deviation

valgus deformity

• lateral deviation of limb distal to location of the deformity

• carpal- distal portion of metacarpus deviates laterally & distal portion of radius deviates medially

• usually toed out

varus deformity

• medial deviation of limb distal to location of the deformity

• carpal- distal portion of metacarpus deviates medially & distal portion of radius deviates laterally

• usually toed in

causes of ALD

• acquired

  • asynchronous growth due to asymmetrical loading of growth plate in distal radius

  • trauma to growth plate (excessive exercise, contralateral limb lameness)

  • rapid growth from over-nutrition

  • mineral inbalances

• congenital

  • in utero mal-positioning

  • laxity of collateral ligaments of carpus (surrounding soft tissue not strong enough to support carpus)

  • hypoplasia of cuboidal carpal bones (defective ossification)

ALD treatment

• depends on age of foal, joint involved, severity of the angle

• options:

  • confinement & altered nutrition

  • splints, braces, casts

  • surgical growth retardation

  • surgical growth stimulation/acceleration

timing for growth plate closures

• distal metacarpus/tarsus= 3-6 months

  • rapid growth peak at 6 weeks

• distal radius & tibia= 2 years

  • rapid growth peak at 3-4 months

rotational deformities

• permanent rotation develops when a bone is abnormally loaded in both frontal & sagittal planes leading to rotation of the limb around the overloaded axis point

• (temporary rotation of the limb from the elbow is not uncommon in narrow-chested foals & will self correct as the chest widens)

identifying deformities

• radiography

• clinical observation at rest

• clinical observation at exercise

ideal forelimb conformation from the side

• line bisecting elbow joint, carpus, & fetlock joint intersects ground 5cm behind heel

• straight column from elbow joint to fetlock

• fetlock angle 125º-135º

deviations from ideal forelimb conformation

• back at the knee

• over at the knee

back at the knee (calf-kneed)

• knee inclines backward

• behind a straight plumb line dropped from the middle of the forearm to the fetlock

• carpal hyperextension overloads dorsal carpus

• poor conformation leading to carpal fractures

over at the knees (bucked knees)

• knee inclines forward

• infront of a plumb line when viewed from the side

• increased stress on flexor tendons/suspensory ligament

ideal hindlimb conformation from the side

line dropped from the tuber ischii should touch the point of the hock & plantar metatarsus and intersect the ground 7.5-10cm behind the heel

deviation from ideal hindlimb conformation

• sickle-hocked

• camped out behind

  • cause inefficiency in propulsion

• post-legged (leg too straight)

hoof balance

• even distribution of forces throughout the foot during weight bearing

• imbalances caused by poor leg conformation

• distortions caused by uneven loading of pressure from above

static hoof balance

• horse standing still

• examine all views of the feet and limbs

  • dorsal

  • palmar

  • lateral

  • solar

dorsopalmar hoof balance

• lateral view

• hoof pastern axis- angle of dorsal hoof wall should be same as line through long axis of pastern

  • 53º-58º

broken back hoof pastern axis

• long toe, under-run heel

• common defect

• often caused by poor foot care

• result in increased strain on the deep digital flexor & delayed break-over

broken forward hoof pastern axis

• club foot if angle >60º

• caused by:

  • coffin joint flexion

  • increased strain on suspensory ligament

  • increased strain on superficial digital flexor tendon

  • increased pressure in the heel

mediolateral hoof balance

• solar view

• trimmed frog

  • frog should bisect hoof & shoe into 2 equal halves

  • frog width should be 50-66% of the frog length

• length of the foot should approximate the width

• both heels are equal length

• line drawn across the weight bearing surface of the heels is perpendicular to axiss of the frog

dynamic hoof balance

• moving horse

• gait from dorsal & lateral

  • foot landing- level to the ground (D) & level or just barely heel first (L)

  • weight bearing

  • foot flight

lameness

clinical sign/manifestation of signs of inflammation, pain, neurological disease, or mechanical defect that result in a gait abnormality characterized by limping

lameness distribution

• 60% front: 40% hind

  • 70:30 with rider

• 95% of forelimb lameness problems occur distal to the carpus

stages of lameness examination

• history

• physical exam

• evaluate gait

• diagnostic anaesthesia

• imaging

• other tests

lameness exam equipment

• head collar & lead rope (or bridle/chifney)

• lunge rein

• lunge whip

• gloves

• hoof testers

• shoe removal equipment

• pen to check back reflexes

• level hard surface to trot on

• lameness assessment form

lameness history

• age- young= likely to be lame from DOD

• specific use

  • used for particular type of performance are predisposed to particular causes of injury

• onset- sudden or insidious

• duration

• progression- is horse improving

• clinical signs- severe/mild, continuous/intermittent

• past & current levels of training

• previous injury & treatment

• response to treatment for present lameness

lameness physical exam

• limb conformation- conformational deficits predispose to musculoskeletal injury

• posture of limbs- resting forelimbs is uncommon

• muscular symmetry

  • atrophy

  • swelling

• foot size- lame limb foot smaller if chronic

• fetlock heights

• joint/tendon sheath distension

  • increased soft-tissue thickness

• manipulate joint to elicit signs of pain

• palpate for increased digital pulses & heat in foot

gait

manner of walking/stepping

beat

number of foot strikes in a single stride cycle

step

distance between footprints of the 2 front/back feet