EXAM 2 - WRITTEN Flashcards
spine alignment
vertebral column has counterbalancing anterior-posterior curves; act as shock absorbers and reduce amount of injury
thoracic and sacral curves offset cervical and lumbar curves
- thoracic and sacral curves - concave anteriorly and convex posteriorly, in sagittal plane; lumbar and cervical curves - convex anteriorly and concave posteriorly; lateral curves - pathological - scoliosis.
at sagittal plane, anteriorly concave curve is primary curve - thoracic and sacral
- lift head and bilateral lifting of lower extremities - antigravity extension actions create secondary curves - cervical and lumbar
neutral position:
(1) ASIS and PSIS level with each other in transverse plane
(2) ASIS in same vertical plane as symphysis pubis
(3) lumbar curve has desired amount of curvature (pelvis tilts anteriorly, lumbar curvature increases (lordosis); pelvis tilts posteriorly, lumbar curvature decreases (flat back)
- lateral pelvic tilt controlled by hip abductors - gluteus medius / minimus, and trunk lateral benders (erector spinae and quadratus lumborum)
- hip abductors and trunk lateral benders hold pelvis level
antigravity muscles
keep body in upright position static / dynamic posture
- hip and knee extensors, trunk and neck extensors
- trunk and neck flexors / lateral benders, hip abductors and adductors, ankle pronators and supinators
postural sway
- ankle plantar flexors and dorsiflexors
- anterior-posterior motion of upright body caused by motion at ankles
- result of constant displacement and correction of center of gravity within base of support
- high center of gravity and small base of support increase amount of postural sway
good posture / alignment
- decreases amount of stress placed on bones, ligaments, muscles, and tendons
- improves function and decreases amount of muscle energy needed to keep body upright
posture - lateral
plumb line aligned to passes slightly in front of lateral malleolus; body segments aligned so plumb line passes through landmarks
posture - anterior
plumb line aligned to pass through the midsagittal plane , dividing body into 2 equal halves
posture - posterior
plumb line aligned to pass through midsagittal plane, dividing body into 2 equal halves
posture - sitting
- shifting weight onto front of vertebrae will increase pressure placed on intervertebral disks; leans forward, disk pressure increases; reaches forward or picks up a weight, disk pressure further increases as weight or length of lever arm increases
- disk pressure is least when lying supine; increases as you stand and increases more as you sit
- lumbar curve decreases when sitting with back unsupported, pressure on intervertebral disks and posterior structures increases; chair with seat inclined anteriorly / kneeling stool decrease disk pressure by tilting pelvis forward slightly; maintain lumbar curve; back is unsupported, increased and sustained muscle contraction is required to keep body upright; extended position more desirable.
- weight onto front part of vertebra, stresses placed on posterior vertebra (facet joints) decreases, here a flexed position is desirable
- chair with lumbar support and/or a slight forward angle to seat helps maintain lumbar lordosis and minimize pressure on the disks; helpful to have adjustable height work station and computer monitor, a keyboard tray, and a chair with adjustable height armrests; maintain vertebral curves, keeping feet flat on floor, low back supported, and upper body in good alignment
posture - supine
- resting, least amount of intervertebral disk pressure, surface avoid loss of lumbar curve, yet soft to conform and give support to normal curves
- In side-lying posi- tion, bottom leg is extended and top leg flexed; pillow between the legs increase comfort for hips in good alignment
- prone - increased pressure placed on neck
gait cycle / stride
- between one foot touches floor until same foot touches floor again
- stride length - distance traveled during
- step - one-half of a stride; two steps (a right and a left) to complete a stride / gait cycle; equal; walking speed / cadence - number of steps taken / minute; slow 70 steps / minute; fast 130 steps / minute
- step length - distance between heel strike of one foot and heel strike of other; increased or decreased walking speed, step length will increase or decrease; regardless of speed, step length remain equal
gait cycle phases:
- stance phase - when foot is in contact with ground; heel strike of one foot and ends when that foot leaves ground; 60% of the gait cycle
- swing phase - foot is not in contact with ground; foot leaves floor and ends when heel of same foot touches floor again; 40% of the gait cycle.
tasks
(1) weight acceptance - very beginning of stance - foot touches ground and body weight begins to shift onto that leg
(2) single-leg support - body weight shifts completely onto stance leg so opposite leg can swing forward
(3) leg advancement - during swing phase
periods of double support (both feet contact with ground at same time) - as one leg is beginning stance phase and other leg is ending stance phase
- as right leg is beginning stance phase and left leg is ending stance phase
- as right leg is ending stance phase and left leg is beginning stance phase
- each 10% of the gait cycle at average walking speed
periods of single support (only one foot is in contact with ground)
- right foot is on ground as left foot is swinging forward
- left foot bears weight and right leg swings forward
- each 40% of gait cycle
period of nonsupport - neither foot is in contact with ground - during running
gait terms
- traditional terms refer to points in time; key points within the gait cycle
- RLA terms refer to periods of time; moving or dynamic nature of gait
gait cycle events
stance phase
As defined earlier, stance is that period in which the foot is in contact with the floor. Traditionally, the stance phase has been broken down into five components: (1) heel strike, (2) foot flat, (3) midstance, (4) heel-off, and (5) toe-off (Fig. 22-3). Some sources give stance phase only four components by combining heel-off and toe-off into one and calling it push-off. Because signifi- cantly different activities occur during these two periods, it is best to keep them separated.
Heel strike signals the beginning of stance phase, the moment the heel comes in contact with the ground (Fig. 22-4). At this point, the ankle is in a neu- tral position between dorsiflexion and plantar flexion, and the knee begins to f lex. This slight knee f lexion provides some shock absorption as the foot hits the ground. The hip is in about 25 degrees of flexion. The trunk is erect and remains so throughout the entire gait cycle. The trunk is rotated toward the opposite (contralateral) side, the opposite arm is forward, and the same-side (ipsilateral) arm is back in shoulder hyperextension. At this point, body weight begins to shift onto the stance leg. In RLA, this is the period of initial contact.
The ankle dorsiflexors are active in putting the ankle in its neutral position. The quadriceps, which have been contracting concentrically, switch to con- tracting eccentrically to minimize the amount of knee f lexion. The hip f lexors have been active. However, the hip extensors are beginning to contract, keeping the hip from flexing more. The erector spinae are active in keeping the trunk from flexing. The force of the foot hitting the ground transmits up through the ankle, knee, and hip to the trunk. This would cause the pelvis to rotate anteriorly, flexing the trunk somewhat, if it were not for the erector spinae counteracting this force.
Foot flat, when the entire foot is in contact with the ground, occurs shortly after heel strike (Fig. 22-5). The ankle moves into about 15 degrees of plantar flexion with the dorsiflexors contracting eccentrically to keep the foot from “slapping” down on the floor. The knee moves into about 20 degrees of flexion. The hip is mov- ing into extension, allowing the rest of the body to begin catching up with the leg. Weight shift onto the stance leg continues. Foot flat is roughly comparable to the RLA period called loading response, which is that period between the end of heel strike and the end of foot flat.
The point at which the body passes over the weight- bearing foot is called midstance (Fig. 22-6). In this phase, the ankle moves into slight dorsiflexion. However, the dorsiflexors become inactive. The plantar flexors begin to contract, controlling the rate at which the leg moves over the ankle. The knee and hip continue to extend; both arms are in shoulder extension, essentially parallel with the body; and the trunk is in a neutral position of rota- tion. In RLA, midstance is the period between the end of foot flat and the end of midstance.
Following midstance is heel-off, in which the heel rises off the floor (Fig. 22-7). The ankle will dorsiflex slightly (approximately 15 degrees) and then begin to plantar flex. This is the beginning of the push-off phase, sometimes called the propulsion phase, because the ankle plantar flexors are actively pushing the body for- ward. The knee is in nearly full extension, and the hip has moved into hyperextension. The leg is now behind the body. The trunk has begun to rotate to the same side, and the arm is swinging forward into shoulder flexion. In RLA, terminal stance is that period between the end of midstance and the end of heel-off.
The end of the push-off portion of stance is toe-off (Fig. 22-8). The toes are in extreme hyperextension at the metatarsophalangeal joints. The ankle moves into about 10 degrees of plantar flexion, and the knee and
ip are flexing. The thigh is perpendicular to the ground. In RLA, preswing is the period just before and including when the toes leave the ground, signaling the end of stance phase and the beginning of swing phase.
swing phase
non–weight-bearing activities:
acceleration - leg is behind body and moving to catch up; ankle is dorsiflexing, and knee and hip continue to flex, moving leg forward
- initial swing - period between end of toe-off and end of acceleration
midswing - ankle dorsiflexors brought ankle to neutral position; knee - maximum flexion (approximately 65 degrees), hip - maximum flexion (at about 25 degrees of flexion); shorten leg, foot clear ground as it swings through; further hip flexion moves leg in front of body and puts lower leg in vertica
- midswing - period between end of acceleration and end of midswing
deceleration - ankle dorsiflexors active to keep ankle in neutral position preparation for heel strike; knee extending, hamstring muscles contracting eccentrically to slow down leg, keeping snapping into extension; leg swung as far forward as it is going to swing; hip remains in flexion
- terminal swing - period between end of midswing and end of deceleration
displacement
vertical displacement of center of gravity - normal amount ~ 2 inches, highest at midstance and lowest at heel strike (initial contact)
horizontal displacement of center of gravity - as body weight shifts from side to side; equal; greatest during single-support phase at midstance; represents the distance body’s center of gravity must shift horizontally onto one foot so that other foot can swing forward; side-to-side displacement ~ 2 inches
width of walking base
durng walk, place feet slightly apart - distance would range from 2 - 4 inches
lateral pelvic tilt
trendelenburg sign - hips move up and down as your pelvis on each side drops down slightly
- occurs when weight is removed from leg at toe-off (preswing)
- dip would be greater if without hip abductors on opposite side (weight-bearing) and erector spinae on the same side working together, keeping the pelvis level
- pelvis drops on right side (non–weight-bearing side), left hip (weight-bearing side) is forced into adduction
- keep pelvis leve - left hip abductors contract to prevent hip adduction, right erector spinae muscle contracts and “pulls up” on side of the pelvis that wants to drop
- step length normally be equal in distance and time; arm swing with opposite leg; trunk rotates forward as leg progresses through swing phase (controls amount of trunk rotation by providing counterrotation); head erect, shoulders level, and trunk in extension
analyzing - view person from
side - step length, arm swing, position of head and trunk, and activities of lower leg
front / back - width of walking base, dip of pelvis, and position of shoulders and head
double v single support
abnormal / atypical - gluteus maximus / rocking horse
trunk quickly shifts posteriorly at heel strike (initial contact); shift body’s center of gravity posteriorly over gluteus maximus, moving line of force posterior to hip joints; foot in contact with floor, requires less muscle strength to maintain hip in extension during stance phase; shifting is extreme backward-forward movement of trunk
abnormal / atypical - gluteus medius / trendelenburg
shifts trunk over affected side during stance phase; hip abductor is weak
(1) body leans over left leg during that leg’s stance phase
(2) right side of pelvis drops when right leg leaves ground and begins swing phase
shifting trunk over affected side is attempt to reduce amount of strength required by muscle to stabilize pelvis
DO NOT confuse with normal amount of dipping of pelvis
abnormal / atypical - quadriceps
compensatory maneuvers
- may lean body forward over quadriceps muscles at early part of stance phase, as weight is being shifted onto stance leg; (normally line of force falls behind knee, requiring quadriceps action to keep the knee from buckling) leaning forward at hip, center of gravity is shifted forward and line of force now falls in front of knee; force knee backward into extension
- using hip extensors and ankle plantar flexors in a closed-chain action to pull knee into extension at heel strike (initial contact)
- may physically push on anterior thigh during stance phase, holding knee in extension
abnormal / atypical - genu recurvatum
hamstrings are weak
- stance phase - knee will go into excessive hyperextension
- no hamstrings to slow forward swing of lower leg during deceleration (terminal swing) part of swing phase, knee will snap into extension
abnormal / atypical - equinus and steppage
ankle dorsiflexors weakness
- flat foot - insufficient strength to move ankle into dorsiflexion at beginning of stance phase, foot will land
- equinus gait - if there is no ankle dorsiflexion, toes will strike first
- foot slap - may not be able to support body weight after heel strike and will thus move toward foot flat (loading response) as they ineffectively eccentrically contract
- drop foot - not being able to slow descent of foot, foot slaps into plantar flexion as more weight is put on leg; during swing phase, they may not be able to dorsiflex ankle; gravity will cause foot to fall into plantar flexion when it is off ground
- steppage gait - knee will need to be lifted higher for dropped foot to clear floor; drum major in a marching band will utilize this gait
abnormal / atypical - waddling
- person stands with shoulders behind hips (balance resting on iliofemoral ligament of hips); increased lumbar lordosis, pelvic instability, and Trendelenburg gait; little or no reciprocal pelvis and trunk rotation occur; swing the leg forward by entire side of body must swing forward; right arm and leg swing forward together and excessive trunk lean of Trendelenburg gait bilaterally
- sore foot limp - triceps surae group (gastrocnemius and soleus) weak; no heel rise at push-off (terminal stance), resulting in a shortened step length on unaffected side; noticeable on level ground, most pronounced when walking up an incline; steppage present
abnormal / atypical - hip flexion contracture
involved hip unable to go into hip extension and hyperextension during midstance and push-off phases (terminal stance); will assume salutation or greeting position in which hip is flexed and person’s trunk leans forward as if bowing; involved leg may also flex knee when it normally would be extended
abnormal / atypical - vaulting gait
knee flexion contracture - result in excessive dorsiflexion during midstance and early heel rise during push-off (terminal stance); shortened step length of unaffected side
- knee fusion present - lower leg will be at a fixed length; length depend on position of joint
- extension, leg will be unable to shorten during swing phase
(1) rise up on toes of the uninvolved leg in a vaulting gait
(2) hike hip of involved side
(3) swing leg out to side
(4) do some variation of the 3
abnormal / atypical - fused hip / bell-clapper
increased motion of lumbar spine and pelvis can greatly compensate for hip motion; decreased lordosis and posterior pelvic tilt allow leg to swing forward; increased lordosis and anterior pelvic tilt will swing leg posteriorly; bell swings back and forth, causing clapper inside to also move back and forth.
abnormal / atypical - circumducted
- leg begins near midline at push-off (terminal stance), swings out to side during swing phase, then returns to midline for heel strike
- abducted gait if leg remains in an abducted position throughout gait cycle
abnormal / atypical - hemiplegic
neurological involvement
- with spasticity there is an extension synergy in involved lower extremity; hip goes into extension, adduction, and medial rotation; knee is in unstable extension; ankle has drop foot with ankle plantar flexion and inversion (equinovarus), present during stance phase and swing phase; involved upper extremity may be in flexion synergy; no reciprocal arm swing; step length lengthened on involved side and shortened on uninvolved side
abnormal / atypical - parkinsonian / shuffling / festinating
- tremors, demonstrates diminished movement; posture of lower extremities and trunk flexed; elbows partially flexed, little or no reciprocal arm swing; stride length greatly diminished, and forward heel does not swing beyond rear foot; person walks shuffling; feet flat and weight mostly forward on toes; has difficulty initiating movements; start slowly and increase in speed, and person has difficulty stopping; feet are trying to catch up to forward-leaning trunk
abnormal / atypical - scissors
spasticity in the hip adductors; most evident during swing phase, when unsupported leg swings against or across stance leg; walking base is narrowed; trunk may lean over stance leg as swing phase leg attempts to swing past it
spinal nerve innervation
