Unit 3 Flashcards
What is fascia lata?
Fascia of the thigh
What is crural fascia?
Fascia of the leg
Compartments of the lower limb and their innervations and their divisions
In the thigh: - Anterior compartment: Femoral n, posterior division - Posterior compartment: Tibial n, anterior division - Medial compartment: Obturator n, anterior division
In the leg:
- Anterior compartment: Deep fibular n, posterior division
- Posterior compartment: Tibial n, anterior division
- Lateral compartment: Superficial fibular n, posterior division
Tarsal tunnel syndrome and problems associated with it
Compression of the tibial nerve as it passes beneath the flexor retinaculum on the medial aspect of the ankle joint.
This can lead to parasthesia or even anesthesia of the plantar surface of the foot, and problems w/ movements of the toes.
Compartment syndrome and problems associated with it
Increased tissue pressure in one of the compartments (like anterior compartment thigh or anterior compartment of leg). May be caused by inflammation resulting from trauma to muscles in the compartment. This inflammation can put pressure on nerves and vessels traveling within or through the compartment. Can lead to ischemia and dysfunction of muscles included in the specific compartment due to decreased blood flow from vessel compression.
Which compartment of the lower limb is one of the more common compartment syndromes?
Anterior compartment syndrome (increased pressure in anterior compartment of the leg)
Lumbosacral plexus innervation; its spinal cord levels; and fiber types
Innervates skeletal muscles and skin of lower limb and pelvis from ventral rami T12-S4.
Carries sensory, motor, and postganglionic sympathetic fibers
Lumbosacral trunk
Serves as a connecting link btwn lumbar and sacral portions of lumbosacral plexus (it’s formed by L4 and L5)
Name the “non-limb” nerve closely related to sacral component of lumbosacral plexus and its spinal cord segments.
What does it innervate?
Pudendal nerve comes from ventral rami S2-S4.
Provides sensory innervation for perineal region and external genitalia, and motor fibers to striated skeletal muscle of external genitalia and external anal sphincter.
Name the major arteries to the lower limb
- Femoral artery
- Superior gluteal artery
- Inferior gluteal artery
- Obturator artery
What is the largest artery in the lower limb?
Femoral artery
What are the branches of the femoral artery?
- Medial femoral circumflex
- Lateral femoral circumflex
- Profunda femoris (deep femoral)
Where are lower limb arteries positioned?
On the flexor side of the joints
How does the femoral artery get to the flexor side of the knee joint?
The femoral artery passes to posterior aspect of the femur near its distal end through the adductor hiatus (hole) in the adductor magnus muscle
When does the femoral artery become popliteal artery?
Femoral artery goes through adductor hiatus and enters popliteal fossa to become popliteal artery.
Branches of the popliteal artery and where it distributes to
- Anterior tibial artery
- Posterior tibial artery
- Fibular artery
Distributes to leg and foot
Branches of anterior tibial artery
- Dorsalis pedis artery
2. Dorsal arch of the foot
Branch and subbranch of posterior tibial artery
- Fibular artery (which branches into lateral and medial plantar arteries to form plantar arch)
Plantar arch gives rise to what arteries?
Common digital arteries
Proper digital arteries
Collateral circulation around the hip is provided through what structure?
Cruciate anastomosis, which forms from 3 branches of the femoral artery (medial femoral circumflex, lateral femoral circumflex, first perforating branch of profunda femoris) and a branch of the internal iliac artery (inferior gluteal artery).
When does lower limb development begin?
~4 weeks gestation; lags behind upper limb
Name the cutaneous nerves of the lumbosacral plexus and their spinal cord segments
- Subcostal (T12)
- Iliohypogastric (L1)
- Ilioinguinal (L1)
- Genitofemoral (L1-L2)
- Lateral femoral cutaneous (L2-L3)
Name the anterior division nerves of the lumbosacral plexus and their spinal cord segments
- Obturator (L2-4)
2. Tibial (L4-S3) (from sciatic nerve)
Name the posterior division nerves of the lumbosacral plexus and their spinal cord segments
- Femoral (L2-4)
- Superior gluteal (L4-S1)
- Inferior gluteal (L5-S2)
- Common fibular (L4-S2) (from sciatic nerve)
What movement is being tested for function of peripheral nerves or spinal cord segment L2-L3?
Hip flexion
What movement is being tested for function of peripheral nerves or spinal cord segment L4-L5?
Hip extension and ankle flexion
What movement is being tested for function of peripheral nerves or spinal cord segment L3-L4?
Knee extension
What movement is being tested for function of peripheral nerves or spinal cord segment L5-S1?
Knee flexion
What movement is being tested for function of peripheral nerves or spinal cord segment S1-S2?
Ankle extension
Varicose veins and its risk factors
Weakening of venous walls; cusp of valves pulled apart and cannot prevent backflow of blood
Risk factors: standing for long period of time, pregnancy, obesity, heredity weakness of veins
Collateral circulation around the knee is provided through what structure?
Geniculate branches off popliteal artery (medial superior geniculate, medial inferior geniculate, lateral superior geniculate, lateral inferior geniculate)
Greater saphenous vein drains into what vein?
Femoral vein in the groin region
Lesser saphenous vein drains into what vein?
Popliteal vein in the popliteal fossa
Skeletal muscle pump
Transports blood against the pull of gravity. Since compartments do not expand when muscles contract, each time muscles contract it also squeezes the veins within the compartment to move the blood upwards. The venous valves prevent the blood from flowing backwards.
Testes exocrine and endocrine functions
Exocrine function: produce sperm in seminiferous tubules
Endocrine function: produce testosterone made by cells called interstitial cells of Leydig
Describe how testes descend during development and how that creates the inguinal canal and rings
Testes (and part of peritoneum) descend from an abdominal position to scrotum by following gubernaculum and pushing through layers of anterior abdominal wall (along with blood vessels and vas deferens) which creates inguinal canal and rings at either end of the canal.
Describe the route of sperm
- In testes, sperm made in seminiferous tubules
- Held in epididymis for maturation/storage
- Travels through ejaculatory ducts to pick up secretions from seminal vesicles
- Travels in vas deferens (ductus deferens) in spermatic cord through inguinal ring/canal
- Goes into urethra
What structures form the spermatic cord?
Vas deferens
Testicular artery and veins
Lymphatic vessels
Autonomic nerve fibers
Male urethra can be subdivided into 3 segments
- Prostatic urethra
- Membranous urethra
- Penile or spongy urethra
Accessory glands associated w/ the male reproductive tract and what they make
- Prostate gland: makes componetns of seminal fluid necessary for sperm maintenance in female genital tract
- Seminal vesicles: make components of seminal fluid for sperm maintenance too
- Bulbourethral glands: release fluid that cleans out urethra of urine and bacteria prior to ejaculation
Ovary exocrine and endocrine functions
Exocrine function: make ova (eggs)
Endocrine function: make estrogen and progesterone
Describe the continuity of male v. female reproductive systems
Male reproductive system is continuous; female is discontinuous
Describe the different types of uterus positions
Anteversion: uterus flipped anteriorly relative to vagina
Retroversion: uterus flipped posteriorly relative to vagina
Retroflexion: uterus flexed posteriorly relative to cervix
Anteflexion: uterus flexed anteriorly relative to cervix
Arteries in the pelvis
- Aorta
- Common iliac a. (external and internal)
- External iliac a. and internal iliac a.
- Internal iliac branches (vesicular, uterine, and rectal a.)
- Superior gluteal a. and inferior gluteal a.
- Internal pudendal a.
- Obturator a.
Describe sympathetic and parasympathetic innervation in pelvic organs
Sympathetic (lumbar and sacral) splanchnics send sympathetic innervation from sympathetic trunk.
Pelvic splanchnics send parasympathetic innervation from S2-4 nerves
Sympathetic and pelvic splanchnics send fibers to inferior hypogastric plexuses and pelvic plexuses.
Sympathetic splanchnics send out sympathetic innervation to pelvic organs to perform what functions?
Inhibit defecation
Emission (phase before ejaculation where sperm moves from testes to urethra)
Pelvic splanchnics send out parasympathetic innervation to pelvic organs to perform what functions?
Allow defecation
Erection
Where can preganglionic and postganglionic cell bodies in sympathetic (lumbar and sacral) splanchnics be found?
Preganglionic: ventral rami of T1-L2
Postganglionic: sympathetic chain
Where can preganglionic and postganglionic cell bodies in pelvic splanchnics be found?
Preganglionic: lateral horn to ventral rami S2-S4
Postganglionic: terminal ganglia
Pelvic diaphragm, what it consists of, and its functions
Floor of pelvis and roof of perineum consists of muscles (levator ani + coccygeus muscle)
Functions:
- Helps w/ fecal continence (via puborectalis)
- Supports pelvic viscera against gravity so they don’t fall out of bottom of pelvis
Describe the pelvic plexuses route innervation to perineal structures
- Posterior to anterior route along pelvic organs
2. Exit inferior to pubic symphysis
Describe the pudendal nerve route innervation to perineal structures
- Exit pelvis through greater sciatic foramen
- Enter perineum through lesser sciatic foramen
- Travel anteriorly through pudendal canal and runs along ischiopubic ramus to get to skin and skeletal muscles
Describe the structures that help fecal continence
- Rectal folds: internal assistance (like KerPlunk) exists to slow down feces from getting to anus
- Internal anal sphincter: smooth muscle in wall of rectum controlled by ANS
- External anal sphincter: combo of 3 voluntary, skeletal muscles that form ring around internal anal sphincter
- Puborectalis: makes a “sling” around external anal sphincter to hold your poop (voluntary muscle)
Describe the somatomotor aspect of fecal continence
Levator ani innervated by direct branches from sacral plexus S2-S4
External anal sphincter innervated by Pudendal n.
Tonic contraction closes external anal sphincter; relaxation allows defecation
Describe the visceromotor aspect of fecal continence
Internal anal sphincter innervated by sympathetic splanchnics and pelvic splanchnics whose fibers go to pelvic plexuses
Smypathetic contracts to close internal anal sphincter; parasympathetic relaxes to allow defecation.
Episiotomy and its alternatives
Surgical cut to perineal body (an anchoring point btwn pelvic diaphragm and urogenital diaphragm which supports pelvic contents) to prevent traumatic tear and allow baby to get through.
Perineal massage and warm compression can help to minimize damage to perineum.
Pelvic organ prolapse; how it can happen and what structures try to prevent it
Organ prolapse through urogenital hiatus due to weakness of pelvic diaphragm.
Can happen after childbirth when retroverted uterus creates pressure where uterus can prolapse out of vagina.
Fat-filled space (ischioanal fossae) superficial to posterior part of pelvic diaphragm helps to keep pelvic organs in. Also have urogenital diaphragm to cover pelvic outlet.
Urogenital hiatus
Opening of pelvic diaphragm which allows urethra and vagina to pass through. It is covered inferiorly by urogenital diaphragm.
Anal hiatus
Opening of pelvic diaphragm which allows anus and rectum to pass through.
Urogenital diaphragm
Covers anterior pelvic outlet. Consists of muscle in the deep space (external urethral sphincter and compressor urethrae) AND CT layers in the superficial space (perineal membrane) (where as pelvic diaphragm is ONLY muscle). It is attached to perineal body.
Describe the structures that help urinary continence
- Internal urethral sphincter: smooth muscle (involuntary), closes during ejaculation to block semen from entering bladder
- External urethral sphincter: skeletal muscle (voluntary)
Describe the somatomotor aspect of urinary continence
External urethral sphincter innervated by pudendal n.
Tonic contraction closes sphincter; relaxation allows urination.
Describe the visceromotor aspect of urinary continence
Internal urethral sphincter innervated by sympathetic splanchnics, pelvic splanchnics, pelvic plexuses.
Sympathetic contracts to close sphincter; parasympathetic relaxes to allow urination.
Types of urinary incontinence and causes
Types:
- Stress (sneeze and pee lol)
- Urge (always feeling like you need to pee)
- Overflow (bladder so full it just opens up flood gates)
Causes:
- Weakness of sphincters (after childbirth)
- Blockage of urethra (BPH, prostate cancer, constipation)
- Neurological problems (MS, Parkinson’s, SCI)
Describe erectile tissues of the penis and the clitoris and their location in relation to the UG diaphragm
Penis:
- Corpora cavernosa (2 dorsal masses)
- Corpus spongiosum (midline mass that contains urethra)
- Tunica albuginea (tough CT that puts a limit on how much erectile tissue can expand)
Clitoris:
- Corpora cavernosa
- Vestibular bulbs (homologous w/ corpus spongiosum in males)
- Tunica albuginea
Erectile tissue are anchored to superficial surface of perineal membrane of urogenital diaphragm
Visceromotor and somatomotor roles in sexual response and their innervation
- Erection: pelvic splanchnics, parasympathetic (male and female)
- Emission: sympathetic splanchnics (male only)
- Ejaculation/orgasm: Pudendal n., somatomotor reflex (male and female)
The perineum can be divided what 2 regions? What do these regions consist of starting with deep to superficial structures?
Urogenital triangle (anterior):
- Peritoneum
- Pelvic organs
- Pelvic diaphragm
- Urogenital diaphragm
- Erectile tissue
- Superficial perineal muscles
- Skin
Anal triangle (posterior):
- Peritoneum
- Pelvic organs
- Pelvic diaphragm
- Ischioanal fossa
- Skin
Sacrioiliac joint description; joint type; auricular surfaces
Synovial joint that connects lower limb to axial skeleton via sacrum and hip bones. Very stable and very little movement.
Sacral auricular surface is hyaline; iliac auricular surface is fibrocartilage
Os coxa/innominate is composed of these 3 bones
Ilium (wing part)
Ischium (what you sit on)
Pubis
Symphyseal surfaces of each pubic bone articulates to each other to form
Pubic symphysis
How many ossification centers does the os coxa have?
8 ossification centers
Triradiate cartilage
Centered in acetabulum of os coxa to hold the 3 bones together (ilium, ischium, pubis) until they fuse (which fuses around ~16 years)
Sacroiliac joint actions
Transverse axis:
- Nutation/anterior rotation
- Counternutation/posterior rotation
Sacroiliac joint ligaments and what movements they resist
- SI joint ligaments
- Sacrospinous ligaments
- Sacrotuberous ligaments
Resist anterior rotation of sacrum during standing (so it doesn’t tip forward too far)
Pubic symphysis
Cartilagenous joint w/ fibrocartilaginous disc in-btwn the symphyseal surface. Has very little movement.
Can have a joint cavity, in which case, it’d be a synovial ojint.
Relaxin
Hormone that “relaxes” ligaments and increases joint laxity for labor and delivery. Allows SI joint and pubic symphysis to widen during childbirth.
Describe the bone structure of the femur and its strength in relation to compression and being bent.
Trabecular bone pattern of femur head/neck follows lines of principle loads which allow for multiaxial load.
It has a thick cortical shell on interior surface of neck to help resist bending forces.
Muscles help turn bending force into compressive force (bc the bone is strongest in compression, not bent)
Femoral neck angles
Neck to shaft angle in coronal plane (affects height):
- Coxa vara (angle less than 120 degrees)
- Coxa valga (angle greater than 135 degrees)
Neck to shaft angle in transverse plane:
- Anteversion (angle pointing anterior, pigeon toed)
- Retroversion (angle pointing posterior, out toed)
When does the external iliac artery change its name? What name does it become?
External iliac artery becomes femoral artery once it cross inguinal ligament.
What happens if the circumflex femoral arteries to the femoral head and neck get blocked or damaged?
Because there are few, if any, collateral channels collecting these vessels w/ vessels associated w/ the shaft of the femur, damage to the circumflex vessels may leave the femorarl head w/ no blood supply at all, resulting in avasular necrosis (death) of the bone.
What are some causes of avascular necrosis (lack of blood supply) of the femoral head? What treatment would need to be done?
Causes:
- Fracture
- Chronic corticosteroid use
- Excessive alcohol use
- Slipped capital femoral epiphysis
Treatment:
- Hip replacement
Describe the iliofemoral (hip) joint
- Ball-and-socket joint
- Large articular surface (big femoral head and huge lunate surface)
- Deeper joint cavity (acetabular fossa) w/ a round ligament that joins the articulating surfaces
- Acetabular labrum makes cavity even deeper
Hip joint ligaments
- Iliofemoral ligament
- Pubofemoral ligament
- Ischiofemoral ligament
Resists hyperextension beyond anatomical standing position.
Spinal arrangement of collagen fibers/ligaments of hip joint
Loosen during flexion; resists and tighten during extension (limited extension to 15 degrees)
Hip joint actions
Transverse axis:
- Flexion/extension
AP axis:
- Abduction/adduction
Vertical axis:
- Medial/lateral rotation
What two points should be kept in mind with respect to analyzing muscle function and the reversal between fixed muscle and movable muscle?
- The relationships of that muscle to a given axis at a joint remain the same
- Pulls of the muscle are simple reversed
Gait cycle
Consists of movement of one limb through a stance phase and a swing phase
Very efficient process (the change of fixed and mobile attachments) that uses gravity and momentum and minimizes energy expenditure
Ways gait cycle can maintain center of gravity
- Pelvic rotation in transverse plane minimizes drop in center of gravity by effectively lengthening limbs
- Knee flexion on full stance. Limb minimizes rise in center of gravity by effectively shortening the limb
- Movement of knees towards midline (adduction of hip) minimizes lateral shift in center of gravity
- Pelvic tilt (drop) on swing side minimizes rise in center of gravity
Saphenous nerve
Branches from femoral nerve and does cutaneous innervation to antero-medial leg
Muscles attached to ilium are innervated by (posterior / anterior) division fibers?
Posterior division
Muscles attached to ischium are innervated by (posterior / anterior) division fibers?
Anterior division
Muscles attached to pubis are innervated by (posterior / anterior) division fibers?
Anterior division
Adductor hiatus
A “hole” in the adductor magnus that allows the passage of the femoral artery and vein into the popliteal fossa
Femoral triangle borders; floor; vessels/nerves
Borders:
- Inguinal ligament (superior)
- Sartorius (lateral)
- Adductor longus (medial)
Floor:
- Iliopsoas
- Pectineus
Vessels/nerves:
- NAVL (Femoral nerve, artery, vein; and lymphatics)
- Great saphenous vein
Route of femoral triangle vessels
Femoral triangle vessels travel down adductor canal to reach thigh.
They reach adductor hiatus where they can go to the posterior side of the lower limb.
Describe the types of contractions hip muscles use during walking
Concetric (propel limb forward)
Eccentric (decelerate limb down)
Isometric (keeps us stabilized)
Which muscle(s) are considered to be primary hip extensors?
Hamstring muscles (semitendinosus, semimembranosus, biceps femoral)
Which muscle(s) are considered to be strongest hip extensors?
Gluteus maximus
Ex: going upstairs, standing up from sitting, running, etc.
Trendelenburg sign
- Weakness of hip abductors causes contralateral (opposite, functioning) side to descend
- Weakness/paralysis on both sides will cause more dramatic gait
- Tendon transfer of hip flexor (iliacus)
Hip extensors function during walking
Help in deceleration of swing of lower limb (eccentric contraction) and then propel body forward (concentric contraction)
Hip flexors function during walking
Help accelerate thigh in swing phase (concentric contraction and decelerate thigh at end of stance phase (eccentric contraction)
Hip rotation function during walking
Helps to lengthen stride
Hip adduction function during walking
Control the position of lower limb during swing phase and keeps center of gravity from shifting laterally.
Hip abduction function during walking
Work primarily when femur is fixed to elevate opposite side of pelvis
“Knee” joints and their articulations
2 synovial joints:
- Tibiofemoral joint: btwn tibial and femoral condyles
- Patellofemoral joint: btwn patella and patellar articular surfaces of femur
Patella is considered to be what kind of bone?
Sesamoid (bone that develops inside a tendon)
Patella functions in patellofemoral joint
- Protects quadriceps tendon
2. Increases mechanical advantage of quads
Patellofemoral joint
Plane joint; could possibly move in any direction
Gliding joint?
Tibiofemoral joint
Biaxial (can flex/tendon and rotate)
Flexibility during locomotion v. stability during standing.
Q-angle (aka bicondylar angle) and its functional importance
Angle btwn the femur and tibia (shaft of femur is at an angle to shaft of tibia; not perfectly lined up)s
This allows for feet to be planted directly underneath us. This increases stability.
Lower leg angles
Genu valgum: Increase in q-angle of knee causes knee to project medially (knock knee)
Genu varus: Decrease in q-angle of knee causes knee to project laterally (bow leggedness)
Describe the knee joint capsule and its structures
Keeps the 2 knee joints together.
Fibrous capsule makes up posterior, lateral, and medial wall (quadriceps make up anterior wall).
Infrapatellar fat pad sits inside anterior joint capsule
Knee ligaments and the movements they resist
Intracapsular ligaments:
- Lateral (fibular) collateral ligament: adduction, rotation
- Medial (tibial) collateral ligament: abduction, rotation
- Anterior cruciate ligament: anterior translation (anterior displacement of tibia on femur), hyperflexion/extension
- Posterior cruciate ligament: posterior translation (anterior displacement of femur on fixed tibia), hyperflexion/extension
True/false: LCL is attached to lateral meniscus
False, tendon of popliteus muscle runs inside fibrous capsule of knee joint. This separates LCL from attaching to lateral meniscus.
Describe the knee menisci and their functions
Fibrocartilage; has good blood supply on its outer 1/3 (where ligaments attach)
Functions:
- Increased surface contact btwn tibia and femur (spread load)
- Help w/ synovial fluid distribution for lubrication
- Help w/ rotation of knee
Describe the movements of knee menisci
- Menisci move posteriorly during knee flexion and move anteriorly during knee extension
- Menisci move during rotation
Knee joint movements
Transverse axis: Flexion/extension
Vertical axis: Medial/lateral rotation
Pick one: (Extension / flexion) has a larger amount of freedom within the knee joint.
Flexion has a larger amount of freedom for flexion than extension
Describe flexion of knee joints
A small amount of gliding causes axis position to change throughout flexion (knee is not a perfect hinge, so transverse axis does not stay in place)
Describe active rotation of knee joints
Occurs when knee joint is flexed. Muscles (hamstrings, mostly) actively medially/laterally rotate tibia on a fixed femur.
Has the most range of motion when knee is flexed 90⁰
Describe passive rotation of knee joints
Involves slight, inevitable rotatory movements of femur on a fixed tibia during final stages of full extension at knee joint. All ligaments of knee are tight and knee is very stable.
Medial rotation occurs when locking knee joint into full extension. Lateral rotation occurs when unlocking knee joint from full extension to flexion.
Coronary ligaments
Attaches each meniscus to the tibia with its strong fibrous bands
Why does passive rotation occur at the knee joint?
Medial condyles are longer than lateral condyles. As the femoral condyles slide posteriorly on the tibia during extension of the knee, lateral condyle stops gliding first bc it is shorter and medial condyle continues to slide posteriorly and femur rotates medially.
Meniscus tears
MCL/LCL tears due to excess rotation of knee may result in menisci tear.
Menisci tears can interfere w/ joint mobility. Alteration of load can lead to osteoarthritis.
Collateral ligament tears
Blows to the sides of the knee or extreme torsion of a flexed knee.
Valgus knee causes more strain on MCL; Varus knee causes more strain on LCL
MCL tears can cause concomitant tear of medial meniscus.
Cruciate ligament tears
ACL tear: hyperextension of knee
PCL tear: posterior displacement of tibia (happens in flexed knee); “Dashboard” incident
How to test for cruciate ligament tears
Anterior and posterior drawer test (pull/push on tibia and see if it comes out anteriorly or posteriorly)
Terrible triad
Traumatic knee injuries can involve multiple ligaments and menisci. Typically ACL, MCL, and LM. Sometimes ACL, MCL, MM.
Occurs more in women than men bc women have wider hips and larger g-angle.
Meniscus repair
“Red zone” usually heals well; may not need surgery.
“White zone” does not heal well and is commonly removed. Treatment may include debridement or adding sutures to tack meniscus down so it doesn’t move too much.
ACL and PCL repair
Partial tears do not usually call for surgery and heals well.
Complete rupture repair depends on needs of patient. Tendon graft repair may be an option.
Knee joint replacement
Damage to knee from arthritis or trauma can require partial or total replacement.
Total knee replacement requires removal of ACL; you can keep PCL depending on what type of implant is required.
During the first year of development, lower limb rotates 180 deg (laterally / medially) until original posteriorly positioned muscles come to lie anteriorly and laterally.
Medially
Structures that pass piriformis inferiorly
- Inferior gluteal artery
- Inferior gluteal nerve
- Inferior gluteal vessel
- Internal pudendal artery
- Pudendal nerve
- Sciatic nerve
Which vein is often utilized for coronary bypass surgeries?
Greater saphenous vein
2 ways you can differentiate btwn male and female pelvises
- Subpubic angle wider in females
2. Sciatic notch wider in females
Why are pelvic inlet and outlet named the way they are?
Baby goes in pelvic inlet to get into pelvis; baby goes out of pelvic outlet to get out of pelvis.
Perineal body
CT structure that connects pelvic diaphragm and urogenital diaphragm just anterior to anus. Muscles of these diaphragms attach here.
Bulbospongiosus covers what erectile tissue?
Vestibular bulbs (females) or corpus spongiosum (males)
Ischiocavernosus covers what erectile tissue?
Crura along ischiopubic rami
Superficial transverse perineal does what?
Supports viscera; runs along edge of UG diaphragm and attaches to perineal body
Superficial perineal muscles include what and do what?
Bulbospongiosus and ischiocavernosus
Functions:
- Restrict blood during erection
- Propulse sperm during ejaculation
The quadriceps femoris muscle is made of what muscles
- Rectus femoris
- Vasus medialis
- Vastus intermedius
- Vastus lateralis
Quadriceps tendon and what it turns into
A single tendon formed by the quad muscles joining together distally. It becomes patellar ligament btwn the patella and tibial tuberosity.
Quadriceps tendon/patellar ligament function
- Decreases wear on quadriceps tendon/patellar ligament
2. Increases mechanical advantage of quadriceps femoris for good extension of knee
Which direction is most common for patellar dislocation; why; and what prevents this?
Lateral dislocation bc of superior, lateral pull of quadriceps on patella
Genu valgum increases chance of dislocation bc increased q-angle.
Bony “block” (everytime you extend knee, you run patella into bondy block) and pulls of muscles (vastus medialis lower fibers are horizontal, so when they contract in full extension, they will pull patella medially) resists dislocation.
Pes anserinus
Insertion point on tibia where gracilis, sartorius, and semitendinosus come together.
It runs posteriorly to knee, wraps around, and comes to side of tibial tuberosity of medial side of tibia.
Describe range of motion for muscles crossing both hip and knee
Range of motion on knee depends on position of hip, and vice versa.
Hamstrings cannot extend hip AND flex knee maximally at same time. Flexion of hip is greater when knee is flexed bc of reduced tension on hamstrings.
A muscle can only get so contracted (active insufficiency); a muscle can only stretch so far (passive insufficiency). Going past insufficiency can cause muscle tears or avulsion from its attachment.
Which muscles are exceptions to the rule that muscles work from anatomical position?
Hamstrings and gastrocnemius are knee flexors, but if you start in flex position, they can extend knee back into anatomical position. Hams will pull superiorly and posteriorly; gastrocnemius will pull inferiorly and posteriorly.
Which muscle allows you to “unlock” your knee from a locked position?
Popliteus can unlock knee by laterally rotating femur to flex. (You cannot flex from a locked knee position)
Describe knee flexion during gait cycle
Stance phase: passive flexion while walking on level ground is mostly due to momentum of body driving knee flexion
Swing phase: active flexion helps keep limb from hitting ground
Describe knee extension during gait cycle
Knee extensors (quads) act as shock absorbers during first part of stance phase (heel strike)
Knee extensors help stabilize knee in stance phase so that knee doesn’t “buckle”
Eccentric contraction of knee extensors during stance phase more pronounced when walking downstairs. Helps slowly lower you down steps to control descent downstairs.
Describe knee rotation during gait cycle
When knee is flexed, it’s medially rotated. When knee is extended, it’s laterally rotated.
Passive rotation of knee could occur during middle part of stance phase as knee is extended (in a locked position)
Boundaries of popliteal fossa and its structures
Superior, medial side: semitendinosus and semimembranosus
Inferior, medial side: gastrocnemius (medial head) and lesser saphenous vein
Superior, lateral side: biceps femoris
Inferior, lateral side: gastrocnemius (lateral head)
Structures: popliteal artery, popliteal vein (its lesser saphenous vein), and tibial nerve and common fibular nerve (sciatic nerve divides in fossa).
A pinprick test btwn the first two toes tests which dermatome and nerve?
L5 dermatome
Deep fibular nerve
Where does femoral nerve enter thigh?
Enters thigh deep to inguinal ligament and lateral to femoral artery
Which branch of the lumbar plexus has a large cutaneous branch extending below the knee?
Femoral nerve
A pinprick test of the skin on the superior side of the big toe tests which dermatome and nerve?
L5 dermatome
Superficial fibular nerve
Sural nerve and its fiber types
Sensory nerve in the calf region (sura) of the leg made up of cutaneous collateral branches of tibial nerve and common fibular nerve.
Contains sensory and postganglionic sympathetic
A pinprick test of the plantar surface of the heel tests which dermatome and nerve?
S1 dermatome
Tibial nerve
Lateral and medial plantar nerves are branches of what nerve?
Tibial nerve
Common fibular nerve branches into what nerves? What fibers do they carry?
Goes around head of tibia and splits into superficial and deep fibular nerve.
Describe the shape of the trochlea of talus
Trochlea of talus is narrow posteriorly and broad anteriorly.
Deltoid ligament and what movement it resists
Extends medial side of ankle btwn tibia and tarsal bones.
Limit outward movements (eversion) of the entire foot.
Which ligament(s) extend on the lateral side of the ankle and named on basis of their attachments? What do they do?
- Anterior talofibular
- Posterior talofibular
- Calcaneofibular
Limit inward movements (inversion) of the foot.
What is the most common ankle sprain?
Forced inversion (with plantarflexion) damaging anterior talofibular ligament.
What kind of joint is ankle joint (aka talocrural)? What are their movements and axis?
Uniaxial joint btwn medial and lateral malleoli of tibia and fibula, and trochlea of talus.
Dorsiflexion (extension) and plantarflexion (flexion) around transverse axis.
Subtalar joint
Btwn talus and calcaneus.
Inversion and eversion around oblique axis.
Transverse tarsal joint
Actually 2 joints:
- Talonavicular joint
- Calcaneocuboid joint
Pronation and supination around longitudinal axis (it is most reasonable to consider only inversion and eversion)
Extensor retinacula
Thickenings of crural fascia that all anterior leg compartment muscle tendons must pass deep to. Prevents bowstringing of tendons.
What type of contraction do plantarflexors use? What movement are they doing?
Concentric contraction to lift heel off of ground and accelerate mass of body.
What is the most powerful plantarflexor?
Gastrocnemius
What is the more “postural” plantarflexor muscle?
Soleus
What is a result of weakness/loss of superficial plantarflexors?
No heel push off and can’t run or jump. Deep posterior leg muscles are not strong enough to push calcaneus off the ground.
Which dorsiflexor muscle is active throughout gait cycle? What kind of contractions does it do throughout the gait cycle?
Tibialis anterior
Eccentric contraction: heel strike and beginning of stance phase
Concentric contraction: end of stance phase
Isometric contraction: keep toes up off ground in swing phase
Shin splints
Muscle fibers become dedtached from tibia. Tears in periosteum and slight compartment syndrome.
Extended overexertion can lead to tibial microfractures (build up of microfractures can lead to traumatic fracture).
Foot drop/steppage gait
Damage to deep fibular nerve affects tibialis anterior which results in inability to dorsiflex foot. Foot drags during swing phase (can’t isometrically contract) and slaps down during heel strike (can’t eccentrically contract).
What is a result of weakness/loss of invertors?
Foot will be more everted; loss of tibialis anterior will lead to some foot drop.
What is a result of weakness/loss of evertors? What is a way to treat this?
Ankle instability and problems w/ arches.
Potential for ankle sprains.
Split tibialis anterior tendon transfer (transfer portion of tibialis anterior tendon from medial attachment to lateral attachment to help provide some ability to evert)
Clunial nerves
Provides cutaneous innervation to posterior gluteal region.
Not part of gluteal nerves.
Where’s the midline and axis for abduction/adduction of the tarsals?
Midline to the 2nd digit.
Vertical axis.
What bones do we stand on? What are the arches of the feet?
Stand on:
Head of 1st metatarsal
Head of 5th metatarsal
Calcaneal tuberosity
Arches:
Transverse arch
Medial longitudinal arch
Lateral longitudinal arch
Describe passive and active support of arches of the foot
Passive: bone (“keystone”) and ligaments (tie bone together)
Active: muscles contracting to pull end of arches together
Ligaments of the foot that support the arch
Calcaneonavicular (spring) ligament Long and short plantar ligaments Plantar aponeurosis (not a ligament technically, but helps arch)
Muscles of the foot that support the arch
Fibularis longus
Tibialis posterior
Flexor digtiorum longus
Flexor hallucis longus
Arch problems
High arches
Splayfoot (fallen transverse arch)
Flat foot (fallen longitudinal arch)
Synovial cavity of the knee joint capsule excludes what structures?
Synovial cavity is continuous btwn the 2 joints inside fibrous joint capsule and excludes intracapsular ligaments and infrapatellar fat pad.
