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45 Cards in this Set

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The major features of the walking gait involve movements at the...(4)
hip joint, knee joint, ankle joint, and metatarsophalangeal joints
Stride
A complete cycle of the walking gait
Each lower limb passes through two periods during a stride:
1) Stance period - During which the foot is in contact with the surface below
2) Swing period - During which the foot is swing forward above the surface below
Heel Strike
A stride is said to begin with the beginning of the stance period, with the first moment of that period called the Heel Strike b/c after the lower limb has been swung forward, the heel of the foot strikes the surface below to begin the stance period.
Initial Contact (IC) Phase
Heel strike begins the first phase of the stance period, which is called the initial contact (IC) phase. The initial contact phase is of very short duration and positions the lower limb to accept support of upper body weight
Loading Response (LR) Phase
The next phase of the stance period is called the Loading Response (LR) phase because the lower limb responds to the loading of upper body weight upon it.
The lower limb rolls forward on its heel during the loading response phase to help sustain the forward momentum of the body.
Action in LR Phase
This mechanism by which the body rocks forward over the heel of the newly planted foot is called Heel Rocker Action. Heel rocker action brings the foot into full contact with the surface below, and the moment at which full contact occurs is called Foot Flat. Foot flat marks the end of the loading response phase and the beginning of the third phase of the stance period.
Mid Stance (MST) Phase and its Action
The third phase of the stance period is called the mid stance (MST) phase because it occupies the mid time phase of the stance period.
An ankle rocker action (in which the lower limb rolls forward around the ankle joint) helps sustain forward body momentum in the mid stance phase. Ankle rocker action helps bring the upper body weight directly over the fully planted foot.
Terminal Stance (TST) Phase and its Action
The fourth phase of the stance period is called the terminal stance (TST) phase. This phase begins with the raising of the heel, called either Heel Rise or Heel Off.
A Forefoot Rocker Action (in which the lower limb rolls forward around the metatarsophalangeal joints) helps sustain the forward body momentum. Forefoot rocker action helps draw the heel up and advance the body ahead of the lower limb.
Pre Swing (PSW) Phase
Upper body weight is unloaded from the lower limb and transferred to the contralateral lower limb during the pre swing phase (the contralateral lower limb is the limb on the other side of the body).
The pre swing phase ends with the forefoot rolling off from the surface below, the final moment of which is called Toe Off because the big toe is the last part of the foot to roll off.
Bony Pelvis
In the lower part of the trunk of the body, the left and right coxal bones are joined with each other and the two lowest bones of the spine (the sacrum and coccyx) to form a bowl-shaped ring of bones called the Bony Pelvis
Pubic Symphysis
In the front of the bony pelvis, a cartilaginous joint called the Pubic Symphysis joins the pubic parts of the left and right coxal bones.
Sacroiliac Joint
In the back of the bony pelvis, a synovial joint called the sacroiliac joint joins the iliac part of the coxal bone on each side with the sacrum.
Sacrococcygeal Joint
In the back of the bony pelvis, a cartilaginous joint called the sacrococcygeal joint joins the sacrum and coccyx.
The joints of the bony pelvis permit very little movement of the bones within the bony pelvis.
How orthopedic surgeons refer to the hip
Orthopedic surgeons refer to the proximal end of the femur as the hip.
Specifically, the hip includes the Head and Neck of the Femur and the Greater and Lesser Trochanters.
Pelvic Fractures - most common fractures and dislocations, morbidity and mortality
-Fractures of the bony pelvis are called pelvic fractures. Since the bony pelvis is structurally a united ring of bones, breaks within the ring generally occur in pairs. The pair of breaks commonly is either a pair of fractures or a fracture accompanied by a joint dislocation.
-The superior and inferior pubic rami are the most commonly fractured parts of the bony pelvis; dislocation of the pubic symphysis is more common than dislocation of the sacroiliac joints.
-There is high morbidity and mortality associated with pelvic fractures because of attendant hemorrhagic shock and pelvic organ damage. In particular, it must always be assumed with pelvic fractures, until proven otherwise, that the bladder and urethra are also damaged.
Hip Fractures - most common
Fractures of the hip are called hip fractures. Fractures of the femoral neck are especially common among the elderly; the contribution of osteopororsis to the genesis of such fractures accounts for the greater incidence of hip fractures among elderly women than among elderly men.
Subcapital Fractures and Avascular Necrosis of the Head of the Femur
-Most femoral neck fractures in elderly individuals occur immediately distal to the head of the femur and thus are called Subcapital Fractures.
-The attendant rupture of the arteries that supply the head of the femur accounts for the common post-traumatic complication of avascular necrosis of the head of the femur.
Slipped Capital Femoral Epiphysis
The epiphyseal plate for the head of the femur changes its orientation during the early years of adolescence, placing the plane of the growth plate in greater alignment with the direction of weight-bearing forces through the hip joint. This change in orientation subjects the epiphyseal plate to greater disruptive shear forces during the course of daily activities. The increased mechanical stress on the epiphyseal plate in combination with certain hormonal imbalances renders young adolescents vulnerable to a fracture of the growth plate for the head of the femur; such a fracture is called a slipped capital femoral epiphysis.
Hip Joint Components, Movement it provides, and Innervation
-The hip joint is a synovial joint in which the Head of the Femur articulates with the Lunate Surface of the Acetabulum of the Coxal Bone and the Acetabular Labrum.
-The hip joint provides for flexion, extension, abduction, adduction, internal rotation, and external rotation of the thigh.
-The Femoral and Obturator Nerves innervate the hip joint.
Acetabular Labrum
The ring of fibrous cartilage that encircles the outer rim of the acetabulum.
Ligament to the Head of the Femur - Location and Key Component
Within the hip joint, a ligament called the Ligament to the Head of the Femur extends from the outer rim of the acetabulum to a pit on the head of the femur called the Fovea Capitis.
Although the Ligament to the Head provides little mechanical support of the joint, it houses an artery called the Artery in the Ligament to the Head of the Femur that supplies blood to the head of the femur.
Joint Effusion
-Injury or infection of a synovial joint typically leads to increased production of synovial fluid within the joint. The increased volume of synovial fluid within the joint is called a Joint Effusion.
-A person suffering from a painful hip joint effusion is most comfortable seated with the painful thigh slightly abducted and externally rotated at the hip joint. This orientation reduces the tension in the synovial membrane to a minimum because it maximizes the encapsulation of the femoral head by the acetabular cavity and labrum.
Primary Osteoarthritis of a Synovial Joint and Superior Joint Space
-Primary osteoarthritis of a synovial joint is the condition in which the normal wear-and-tear stresses on the joint from daily activities lead to thinning of hyaline cartilage surfaces within the joint.
-Primary osteoarthritis of the hip joint typically produces thinning of the hyaline cartilage surfaces in the Superior Joint Space (which is the space between the roof of the acetabular cavity and the upper surface of the femoral head), causing a smaller height of space in between the acetabular cavity and femoral head.
Functions (1), Contributions when someone is sitting and gets up, and Innervation of Gluteus Maximus
-Is the gluteal muscle that extends the thigh. It is the largest gluteal muscle
-When a person rises from a seated position, the left and right gluteal maximus muscles raise the person from his seat and each muscle extends the trunk of the body relative to the thigh by pulling on the back of the bony pelvis from the thigh.
-It is innervated by the Inferior Gluteal Nerve
In terms of the walking gait, the gluteus maximus is most active during what phases of the swing period (1) and stance period (2)
When walking, gluteus maximus is most active during the terminal swing phase of the swing period and the IC and LR phases of the following stance period.
Gluteus Maximus during the terminal swing phase (TSW) of the Swing Period
 During the late part of the TSW phase, gluteus maximus acts to restrain forward movement of the thigh. The muscle restrains forward thigh movement by pulling on the back of the thigh from the bony pelvis.
Gluteus Maximus during the IC and LR Phases of the Stance Period
During the IC and LR phases, gluteus maximus acts to oppose the tendency of the body to fall forward about the hip joint by pulling on the back of the bony pelvis from the thigh.
The trunk of the body has a tendency to fall forward at the hip joint during these two phases because upper body weight is being loaded upon the limb along a line that projects anterior to the hip joint.
Gluteus Maximus Gait
Individuals who suffer from paralysis of Gluteus maximus adopt an abnormal gait called the Gluteus Maximus Gait in which they lean the body trunk backward at heel strike in order to compensate for the loss of the muscle’s contribution to the IC and LR phases of the walking gait.
Gluteus medius and gluteus minimus function (1) and innervation
-Gluteus medius and gluteus minimus are two of the three gluteal muscles that abduct the thigh at the hip joint. -Gluteus medius and minimus are both innervated by the Superior Gluteal Nerve.
During the IC, LR and MST phases, gluteus medius and minimus act to...
During the IC, LR and MST phases, gluteus medius and minimus act to oppose the tendency of the body during these three phases to fall medially downward at the hip joint (to fall downward on the medial side of the hip joint).
During the IC, LR and MST phases, gluteus medius and minimus act to...
During the IC, LR and MST phases, gluteus medius and minimus act to oppose the tendency of the body during these three phases to fall medially downward at the hip joint (to fall downward on the medial side of the hip joint).
Lateral Pelvic Tilting Action
The left lower limb support of upper body weight decreases as the right lower limb goes through the IC and LR phases; this loss of left lower limb support causes the left side of the pelvis to drop, or sag.
The gluteus medius and minimus muscles around the right hip joint, however, minimize this downward, or medial, tilt of the pelvis at the right hip joint by pulling on the bony pelvis from their attachment to the femur. Because this pull tilts the pelvis upward, or laterally, at the right hip joint, the pull is called a lateral pelvic tilting action.
When walking, gluteus medius and minimus are the chief muscles responsible for the lateral pelvic tilting action exerted during the IC, LR, and MST phases. The bony pelvis typically tilts 3o to 4o downward at a lower limb’s hip joint as the lower limb passes through the MST phase.
What happens during a physical examination when testing the patient's lateral tilting action if the action is normal?
The patient raises the left foot off the ground. As the left foot is raised off the ground, gluteus medius and minimus on the right side exert their lateral pelvic tilting action to slightly elevate the left side of the pelvis. Elevation of the left side of the pelvis shifts the center of gravity of the upper body toward the right side, thereby helping the patient to balance the upper body over the right lower limb.
What happens during a physical examination when testing the patient's lateral tilting action if the action is not normal?
As the left foot is raised off the ground, the left side of the pelvis drops because of the inadequacy of gluteus medius and minimus on the right side. This abnormal dropping of the pelvis on the unsupported side is called Trendelenburg’s Sign (for the right side).
Gluteus Medius Gait
Individuals who suffer from weakness or paralysis of gluteus medius and minimus compensate for the loss of the lateral pelvic tilting action of the gluteus medius and minimus muscles by adopting an abnormal gait called the gluteus medius gait.
Let’s examine the Gluteus Medius gait in a person whose gluteus medius and minimus muscles are weak in the right lower limb.
-When this person walks, he/she pushes off with the left foot (as the left lower limb passes through the PSW phase) to lean the upper body toward the right and temporarily balance it over the right lower limb as the right lower limb passes through the LR, MST, and TST phases.
-Persons with a painful, osteoarthritic hip joint adopt a gluteus medius gait to minimize hip pain when walking.
Why would a person with a painful, osteoarthritic right hip joint want to reduce lateral pelvic tilting action at the joint by the gluteus medius and minimus muscles?
When walking, the total compressive force acting across the right hip joint during the phases of the swing period increases severalfold during the LR, MST, and TST phases of the stance period, causing the hip joint to be compressed by the burden of bearing most or all the gravitational weight of the upper body but also by the lateral pelvic tilting action exerted by gluteus medius and minimus.
However, if the person pushes off with the left foot to lean the upper body toward the right side and balance it over the right lower limb during these phases, gluteus medius and minimus around the right hip joint exert less lateral pelvic tilting action; this reduces the total compressive forces acting across the right hip joint and thus decreases the pain in the joint.
Tensor Fasciae Latae Function (1) and Innervation
-Tensor fasciae latae is the third of the three gluteal muscles that abduct the thigh at the hip joint through its capacity to tense the iliotibial tract.
-When walking, tensor fasciae latae exerts a lateral pelvic tilting action during the IC, LR, MST and TST phases. -Tensor fasciae latae is innervated by the Superior Gluteal Nerve.
Iliotibial Tract
The iliotibial tract of the thigh is a thick band of fascia that extends from the iliac crest of the coxal bone above to the lateral condyle of the tibia below. It is basically the lateral thickening of the fascia lata.
What are the 5 gluteal muscles that externally rotate the thigh at the hip joint and how are they innervated?
1) Piriformis
2) Superior gemellus
3) Obturator internus
4) inferior gemellus
5) Quadratus femoris
-They are the deepest muscles of the gluteal region.
-They are innervated by nerves derived from the Sacral Plexus.
Sacral Plexus
-In the pelvis on each side, nerve fibers from the anterior rami of L4, L5, S1, S2, S3, and S4 form a plexus, or network, of nerve fibers called the Sacral Plexus.
Lumbosacral Trunk
-The L4 and L5 nerve fibers that contribute to the sacral plexus enter the plexus as a nerve bundle called the lumbosacral trunk.
-The sacral plexus gives rise to all the nerves that innervate the gluteal muscles.
Sciatic Nerve - where does it come from, what is it derived from, where does it extend into?
-The sacral plexus gives rise to the sciatic nerve, which is the largest nerve in the body.
-The sciatic nerve is derived from nerve fibers in the anterior rami of L4, L5, S1, S2, and S3.
-The sciatic nerve extends from the sacral plexus into the gluteal region by passing through the greater sciatic foramen. It follows an inferolateral course through the lower medial quadrant of the gluteal region before extending inferiorly into the back of the thigh at a point midway between the ischial tuberosity and the greater trochanter of the femur.
Safest Place in the Buttock for Intramuscular Injections and why
-The sciatic nerve is the single most important gluteal structure at risk of injury by an intramuscular injection in the buttock.
-Because the sciatic nerve passes through the lower medial quadrant of the buttock, the upper lateral quadrant of the buttock is the safest quadrant for intramuscular injections.