ACSM chapter 3.4 specific anatomy part 3 (knee, ankle, foot, and spine)

Close packed or locked position of the knee

"screwing home" mechanism, in which the last few degrees of knee extension (straight knee), the tibia externally rotates on the femur.

"Q angle"

angle of the knee formed from the line connecting ASIS (anteior superior iliac spine) to the center of the patella and the line connecting the center of the patella to the tibial tuberosity. Determines the line of pull of the patella at the patellofemoral joint. Normal angle for females is 18*, and males 13*. Below normal (negative) results in a genu varum position of the knee (bow-legged), whereas a Q angle that is above normal results in a genu valgum position (knocked-kneed)

Vasti muscles (3): lateralis, intermedius, and medialis

anterior knee muscle that originates from the proximal femur. Lateralis and medialis are pennate muscles that pull on the patella at oblique angles.

Quadriceps muscles

anterior muscles of the knee comprised of the rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. Acts to extend the knee joint. Inserts into the superior aspect of the patella and the tibial tuberosity by the patellar ligament

Anterior Cervical muscles of the spinal column

anterior muscles of this region include sternocleidomastoid, scalenes (anterior, middle, and posterior), longus capitis, and longus colli muscles. During unilateral contrations, the anterior scalene, longus capitis and colli, and sternocleidomastoid muscles flex the neck and head. On bilateral contractions, the anterior scalene, longus capitis and coli and sternocleidomastoid muscles flex the neck and head. The scalenes attach proximally to the upper cervical transverse processes and distally to the upper two ribs. The sternocleidomastoid attaches proximally to the mastoid process of the occiput and distally to the sternum (medial head) and clavicle (lateral head). The longus muscles run from the transverse process of the upper cervical vertebrae to the anterior aspect of the superior cervical vertevrae (longus colli) or the base of the occiput (longus capitis).

Patellofemoral joint

arthrodial joint, formed by the posterior aspect of the patella and patellofemoral groove between the condyles of the femur.

Plantar fasciitis

chronic inflammatory condition that typically results in pain at the calcaneal insertion of the plantar fascia. Usually caused by chronic pulling on the plantar fascia, tight Achilles tendon, hyperpronation, or other factors that overload the fascia (ex. obesity). Treatment includes stretching and strengthening exercises fo the posterior claf muscles, orthoses to correct hyperpronation, and physiotherapy modalities and medication to reduce inflammation. Sometimes surgery is required to release it. It's also highly associated with calcaneal heal spurs.

What is pronation

combination of talocrural dorisflexion, subtalar eversion, and forefoot abduction.

What is supination

combination of talocrural plantar flexion, subtalar inversion and forefoot adduction.

Pes anserinus

combination of the sartorius, gracilis, and semimembranosus tendons, inserts to the anteromedial aspect of the proximal tibia, just inferior to the tibial tuberosity

Patellofemoral pain syndrom

common disorder in young athletes (particularly females), produces anterior knee pain. often caused by an off-center line of pull of the patella, which irritates the joint surface and retinaculum of the knee. Can result from insufficiency muscular imbalance during knee extension and from excessive varus and valgus stresses from Q angles outside of the normal range of 13*-18*.

ligamentous sprains and tears of the knee

common injury, particularly for athletes, due to this joints structure and insertion points, anterior cruciate ligament is more frequently injured compared with the posterior cruciate ligament. ACL injured during external rotation of the the tibia along with valgus force of the knee (or planted foot twisted knee).

flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus

deep posterior muscles of the ankle, all but popliteus are ankle plantarflexors and inverters.

What is valgus force? In the knee?

distal segment of a joint deviates laterally while the proximal segment deviates medially. (pronation)

Menisci of the knee

fibro cartilage discs that improve congruency of the joint surfaces, allowing better distribution of joint pressure), add stability, aid in shock absorption, provide joint lubrication, aid in load bearing, add anterior-posterior stability, and protect articular cartilage.

bone structures of the foot

first 26 articulating bones in three functional units: anterior (forefoot), middle (midfoot) and posterior (hindfoot). Forefoot contains metatarsals (one for each digit) and 14 phalanges (toes), 3 for 2-5, and 2 for the big toe. Midfoot contains five tarsal bones: navicular, cuboid, and three cuneiforms. Hindfoot contains the talus and calcaneous bones. Dome of the talus articulates with the distal tibia and fibula and provides the link between the leg and foot at the talocrural joint.

Posterior muscles of the knee

hamstrings (biceps femoris (lateral), semitendinosus(medial), and semimembranosus(more medial)), Sartorius(although on the front it inserts in the medial posterior region of the knee), gracilis(medial), popliteus (back open portion of the knee), and gastrocnemius (calf heads). https://www.bing.com/images/search?q=posterior+muscles+of+the+knee&view=detailv2&&id=ABD20ECAA6BB2DC9C774AEE372FC7DFD305BF4F8&selectedIndex=0&ccid=QPnmz7Ht&simid=608009620289815292&thid=OIP.M40f9e6cfb1eda63797543b8ab67028f8H0&ajaxhist=0

Bony curviture of the spine

in the sagittal plane, the spinal column normally curves 4 times, the mechanical advantagious and improves load-bearing capabilities. convexity posterior (out curve posterior), kyphosis. convexity (outer curve anterior) is anterior, lordosis. Cervical and lumbar regions have lordosis. thoracic and sacral regions have kyphosis. Deviation in sadittal plane are reffered to as hyperlordosis or hyperkyphosis. In the frontal plane the spinal column should normally be positioned in the midline. Lateral deviations are referred to as scoliosis.

Biceps femoris (lateral hamstrings)

posterior muscle of the knee, contains a long head (originating from the ischial tuberosity and is a two-joint muscle) and a short head (which originates from the mid femur). Inserts into the lateral condyle of the tibia and head of the fibula. Acts to flex and externally rotate the knee and extend and externally rotate the hip.

Sartorius muscle

posterior muscle of the knee, originates from the ASIS (anterior superior iliac spine) and inserts on the medial posterior aspect of the knee, acting on the knee and hip.

Basics of the knee

the joint is the largest joint in the body. It is able to bear the load of the upper body and trunk and is crucial for locomotion, it is frequently subject to overuse and traumatic injuries.

What are the main muscles of the ankle and foots

the main muscles lie in the leg, and typically grouped by compartmental location- anterior, lateral, superficial posterior, and deep posterior.

Basic muscles of the spinal column

the spine and trunk muscles exist in pairs, one on each side of the body. Bilateral contraction results in movement in the sagittal plane. The anterior muscles flex the spine, whereas the posterior muscles extend the spine. Unilateral contraction results in lateral bend or axial rotation.

Meniscui injuries

this injury is prone to athletes, the medial form is more frequently torn than the lateral form, due to it's attachment to the medial collateral ligament. It is poorly innervated, relatively avascular, not much pain can be sensed and makes it slow to recover.

Anterior and Lateral muscles of the ankle and foot

tibialis anterior, peroneus (fibularis) tertius, extensor digitorum longus, and extensor hallucis longus, are ankle dorsiflexor muscles. https://gymnasticsinjuries.files.wordpress.com/2012/09/anterioranklemuscles.jpeg

Movements of the knee

tibiofemoral joint flexion-extension in the sagittal plane, ROM of 140*, 0* being full extension (knee straight) and 140 being full flexion (knee bent) internal and external rotation in the transverse plane, 30* internal rotation and 45* external rotation achieved at the knee. Final few degrees of extension, the tibia externally rotates on the femur which brings the knee into a close-packed, or locked, position ("screwing home")

Joints of the knee

tibiofemoral, and patellofemoral joints

Terrible triad injury

traumatic sports injury in which the anterior cruciate ligament, medial collateral ligament, and medial meniscus are damaged simultaneously

Patella (kneecap)

triangular sesamoid bone that is located within the patellar tendon of the quadriceps muscle group. Protects the anterior knee and creates an improved angle of pull for the quadriceps muscles, resulting in a mechanical advantage during extension

ankle sprains

most common of these injuries is to the lateral side because it has less bone stability and ligament strength on the lateral side. Mechanically caused by excessive inversion (rolling of the ankle), Anterior talofibular ligament is most frequently sprained in inversion injuries

Injury to the cervical region of the lumbar spine

most mobile region of the spine, and relatively small cervical muscles are responsible for supporting the head making it vulnerable to instability and injury. Most dangerous injuries are traumatic fractures and dislocations that result in instability of the column. The combination of axial compression and hyperflexion is a common mechanism for severe cervical injuries such as these. Direct consequences include neural damage to the upper spinal cord, which may result in paralysis or death. Any other injury should be treated as a medical emergency. Sprains and strains of the neck muscles and ligaments are frequently the result of biolent hyperextension-hyperflexion from sudden acceleration-deceleration, such as a head-on car collision, aka whiplash, which can cause tears of the anterior and posterior structures of the cervial region including the muscles (ex. sternocleidomastoid, upper trapezius, and cervical paraspinals) and ligaments. other injuries can include instability, disc herniation. Treatments include passive modalities, stretches, and strengthening exercises for the neck.

achilles tendon rupture

most serious acute injury to the leg. 75% accure in males between 30-40 yoa. Typically mechanical, a forceful plantarflexion while knee is extended, usually requiring surgical repair and extensive long-term rehabilitation.

extensor hallucis longus muscle

muscle that acts to extend the big toe

peroneus tertius muscles (longus and brevis)

muscle that everts (standing on the medial edge of foot) the foot (frontal plane adduction, medial region of the foot presses down while lateral aspect raises up). http://classconnection.s3.amazonaws.com/497/flashcards/2760497/jpg/peroneus_tertius-13E807B8A2057602AAD.jpg

extensor digitorum longus muslce

muscle that extends digits 2-5

flexor digitorum longus muscle

muscle that flexes digits 2-5

Tibialis anterior muscle and tibialis posterior

muscle that inverts (standing on the lateral edge of foot) the foot (frontal plane abduction, lateral aspect of the foot presses down, medial aspect raises up)1

Anterior muscles of the lumbar of the spinal column

muscles of the abdominal group in the spinal region: rectus abdominis, internal and external abdominal oblique, and transversus abdominis. Rectus abdominis originates from the pubic bone and inserts at the 5th thought 7th ribs and xiphoid process. The rectus abdominis exists as two vertical muscles separated by a connective tissue band, the linea alba. Horizontallly, the rectus abdominis appears to be separated by three distinct lines. These lines represent areas of connective tissue that support the muscle in place of attachment to bones. The rectus abdominis is the primary trunk flexor and through its attachment to the pubic bone, it also tilts the pelvis posteriorly. The internal and external obliquus abdominis musles rotate the trunk on unilaterl contraction and fles the trunk on bilateral contraction. The transversus abdominis runs horiontally, attaching medially to the linea alba via the abdominal aponeurosis and laterally to the thoracic fascia, inguinal ligament, iliac crest, and the lower six ribs. Contraction of the transversus abdominis stabilizes the lumbar spine and increasesintraabdominal pressure, and aberrant firing patters of the transversus abdominis appear to be related to low back pain. To isolate the abdominal muscles during trunk flexion exercise, it is advisable to shorten the psoas and other hip flexor muscles (active insufficiency) by flexing the hips and knees. The crunch with the hips and knees flexed may be more effective in conditioning the abdominals than straight knee sit ups.

Lateral Cervical muscles of the spinal column

muscles of the lateral aspect of the neck and head include the levator scapulae and upper trapezius muscles, both latterally bend and rotate the neck on unilateral contractions. The upper trapezius extends the neck as well on bilateral contraction. The levator scapulae attaches superiorly to the transverse processes of the upper four cervical vertebrae and inferiorly to the vertebral border of the scapula above the spine. The upper trapezius attaches proximally to the occiput and spinous processes of the cervical vertebrae and distally to the clavicle and acromion of the scapula. The levator scapulae and upper trapezius muscles also cause movement of the scapulothoracic joint as discussed in the shoulder section.

Posterior muscles of the lumbar of the spinal column

muscles of the posterior musculature of the lumbar spine consist of three muscle gorups: eractor spinae, multifidus muscles, and intrinsic rotators. The latissimus dorsi usually acts on the shoulders, extends and stabilizes the lumbar spine through its attachment to the thoracolumbar fascia. The erector spinae group lies lateral and superficial to the multifidus, is divided into the iliocostalis lumborum and longissimus thoracic muscles. Muscles are separated from each other by the lumbar intramuscular aponeurosis, with the longissimus lying medially. The longissimus and iliocostalis are composed of several multisegmental fascicles, allow extension and posterior translation when the muscles are contracted bilaterally. The fascicular arrangement of the multifidus muscle suggests that the multifidus acts primarily as a sagittal rotator (extension without posterior translation) Lateral flexion and axial rotation are possible for both the multifidus and erector spinae musculature during unilateral contraction. The iliocostalis may be better suited to exert axial rotation on the lumbar vertevral motion segment than either the longissimus or multifidus muscles. their anatomical and biomechanical properties, the posterior lumbar muscles are particularly adadapted to maintain posture and stabilized the spine and trunk. The intrinsice rotators, rotatores, and intertransversarii muscles are primarily length transducers and position sensors for the vertebral segment. http://classconnection.s3.amazonaws.com/524/flashcards/1548524/jpg/erector-spinae-iliocostalis-longissimus-spinalis1351390806576.jpg

Posterior Cervical muscles of the spinal column

muscles of the posterior suboccipital, splenius (capitis and cervics), erectore spinae (spinalis, longissimus and iliocastalis). Suboccipital muslces, attach the upper cervical vertebrae to the occiput, extend the head when they contract bilaterally, and laterally bend and rotate the neck when they contract unilaterally.

flexor hallucis longus muscles

muscles that flex the big toe

Ligaments of the ankle and foot

100 ligaments in the joint region, lateral side contains the major anterior and posterior talofibular and the calcaneofibular ligaments. Deltoid ligament complex (medial side) is on the medial ankle and includes the tibiocalcaneal, anterior and posterior tibiotalar, and tibionavicular ligaments. Plantar calcaneonavicular ligament (spring ligament) of the foot helps support the talus and maintains the longitudinal arch. Two arches that shape the foot and distribute body weight from the talus to the foot, in which muscles provide secondary support.

Other chronic foot and ankle injuries bunions, neuromas, Achilles tendonitis, and calcaneal bursitis.

Chronic injuries, frequently due to structural problems of the foot and ankle, such as, hyperpronation or hypersupination (high arch vs pes cavus). unillateral hyperpronation or hyperuspination may cause instability and proprioceptive difficulties at the ankle and postural imblance and mechanical problems to proximal join strucutres in the kinetic chain.

Bony structure of the spine

Comprised of irregular bones, vertebrae, stacked on top of each other. 24 individual vertebrae 7 cervical (neck), 12 thoracic (mid back), and 5 lumbar (lower back). Superior cervical vertebra (C1) artculates with the occipital bone of the skull, inferior lumbar vertebra (L5) articulate with the sacrum. Size increases from cervical to lumbar region due to increase load bearing responsibility. Anterior element: vertebral body, is oval with flat superior and inferior surfaces for articulation with the adjacent vertebral bodies. Posterior elements or posterior arch, contain pedicles and laminae, join anteriorly at the body and posteriorly at the spinous process to form the vertebral foramen (canal), providing a space for the spinal cord to pass. Posterior arch also contains facets on each side and top and bottom for articulation with adjacent vertebrae. Spinous and transverse processes are bony protubrances that provide attachment points for the spinal musculature.

What are the bones of the knee joint?

Distal femur, proximal tibia, and patella (Fibula is not considered part of the knee joint)

What is a varus force? In the knee?

Distal segment of a joint deviates medially while the proximal segment deviates laterally. (supination)

Injuries to the knee basics and factors (9)

Frequently injured joint, vulnerable to acute and repetitive use damage at its ligaments, menisci, and patellofemoral joint. Most injuries require rehabilitation, and sometimes surgery. Predisposing factors to knee injury include: a. Lower extremity malalignment (Q angle abnormalities, flat feet, b. Limb length discrepancy c. Muscular imbalance and weakness d. Inflexibility e. Previous injury f. Inadequate proprioception (balance) g. Joint instability h. Playing surface and equipment problems i. Slight predominance in females (particularly for patellofemoral problems).

intervertebral discs of the spinal column

Important structures of the spinal column that provide load bearing, shock absorption, and stability to the vertebral column. Located between the vertebral bodies and constitute about 20-30% of the height of the vertebral column. Each is motion segment contains a disc, except for the articulation between the first and second cervical vertebrae (atlas and axis). Disc consists of the nucleus pulposus, annulus fibrosis, and endplates. Composed of carious concentrations of water, collagen, and proteoglycans. Nucleus pulposus, located in the center of the disc, is gel-like and more liquid than the annulus fibrosis, dehydrates with age, resulting in decreased body height with age. The annulus fibrosis, located at the periphery of the disc is a more rigid structre and contains more collagen fibers than the nucleus. Oblique arrangement of the collagen fivers of the annulus helps the annulus resist tensil and compressive fores in various planes. Annulus is more susceptible to tearing with movements involving rotation and flexion under load. Vertebral endplates are think layers of fibrocartilage that cover the inferior and superior aspects of the vertebral body and help anchor the disc to the vertebrae. http://www.mille-soeren.dk/20_du_kan_redde_liv/20a_anatomy_pictures/06_Vertebral_and_Intervertebral_Disc_Anatomy.jpg

Lateral muscles of the lumbar of the spinal column

Later muscles of the lubar spine include the quadratus lumborum and psoas (major and minor). The quadratus lumborum originates from the iliac crest and inserts at the 12th rib and transverse process of the lower four lumbar vertebrae. The quadratus lumborum produces lateral bending of the lumbar spine with unilateral contraction and stabilizes the trunk with bilateral contraction. The psoas major muscle originates from the anterior surfaces of the lumbar vertebrae and inserts at the lesser trochanter of the femur. the psoas major flexes the trunk and the hip.

Bony structure of the spine and rib cage

Ribs attach at each of the 12 thoracic vertebral bilaterally and form the thoracic cage. The 7 superior pairs of the ribs are considered true ribs and attach directly to the sternum, 5 lower ribs considered false ribs, attach indirectly to the sternum by the costal cartilages. the two inferior pairs of false ribs do not attach to the sternum and are considered floating ribs.

Basic movement of the spinal column

Spine is capable of motion in all planes, the extent of motion varies with region. cervical spine, atlantooccipital joint allows flexion and extension and slight lateral flexion. Atlantoaxial joint allows primarily rotation. Remaining cervical joints allow flexion and extension, lateral flexion, and rotation. the thoracic joints low moderate flexion, slight extension, moderate lateral flexion, and rotation. The lumbar joints allow flexion and extension, lateral flexion, and slight rotation.

Joints of the foot and ankle

Synovial, hinge-type joint of the ankle is between the distal tibia and fibula and the dome of the talus. Tight fibrous syndesmosis between tibia and fibula unites the distal ends of the bones and forms a "malleolar mortise" into which the trochlea or "dome" of talus fits. Subtalar joint is a plane synovial joint between the talus and calcaneous. Many other joints in the foot exist, such as the ones between the tarsal bones allowing varying degrees of movement, along with tarsometatarsal, intermetatarsal, metatarsophalangeal, and interphalangeal joints.

Movement of the ankle and foot

Talocrural joint allows 15-20* of dorsiflexion and 50* Plantarflexion in the sagittal plane. Subtalar joint allows 20-30* of inversion and 5-15* of eversion in the frontal plane. Midtarsal and tarsometatarsal joints permit gliding motion. Metatarsophalangeal and interphalangeal joints primarily allow flexion and extension of the digits in the sagittal plane. Pronation and supination are combination movements at the ankle and foot that allow the foot to maintain contact with the ground in a variety of stances or on uneven ground. http://study.com/academy/lesson/eversion-of-foot-definition-movement.html

What is the largest joint in the body?

The knee joint

What is the job of the two arches of the foot?

The plantar aspect of the foot that gives it's shape and distributes body weight from the talus to the foot during various load-bearing conditions. Various ligaments and bones primarily support the arches, with muscles providing secondary support. Longitudinal arch extends from the calcaneal tuberosity to the five metatarsals, whereas the transverse arch extends crosswise from the medial to lateral in the midtarsal region. Plantar fascia or plantar aponeurosis (underside of foot) is a strong fibrous connective tissue that provides support for the longitudinal arch. Acts as an extension of the calcaneal (Achilles) tendon of the plantarflexor muscles. Acts like a spring during weight bearing phase of gait, storing mechanical energy then releasing it at foot push-off.

Bone structure of the ankle

This joint if formed by the fibrous union of the distal tibia, medial malleoulus of the tibia, and the lateral maleolus of the fibula. Talus is superior to the calcaneous, between the malleoli of the tibia and fibula. Most calcaneous represents the posterior projection of the heel, and provides important attachment sites for this joint's plantarflexor muscles.

What is the spine?

This joint is an intricate multijoint structure that is crucial in functional mechanics. Link between upper and lower extremities, protects the spinal cord, enables trunk movement in three planes. Sever injury could result in severe impairment of physical function

Injuries to the ankle and foot

This joint is used daily, and is burdens with lots of forces, walking, running, jumping, lifting. Therefore it is often susceptible to traumatic and overuse injuries frequently. Acute muscular strains, cramps, ligament sprains, excessive inversion, anterior talofibular ligament sprain, Achilles tendon rupture. Plantar fascitis, bunions, neuromas, achilles tendonitis, and calcaneal bursitis. Unilateral hyperpronation, or hypersupination.

Injuries to the lumbar region on the spinal column

injuries to the lumbar region, 60-80% of of the general population have some for of lower back pain in their life time. 20-30% suffer at a given time. Diagnosis is difficult and elusive, often no identifiable source of pain. Can be experience secondary to a wide variety of other medical conditions or musculoskeletal (ex. abdominal aneurysm, kidney infection, cancer) which should be ruled out. Other causes include intervertebral disc herniation, facet joint inflammation, muscular strains, and ligamentous sprains. Injuries can be traumatic caused by inappropriate lifting, falling or degeneration, caused by deconditioned lumbar spine, poor posture, prolonged mechanical loading or poor body mechanics during work home or sports. Common cause of lumbar disc herniation is forceful flexion and rotation of the lumbar spine. a protruding disc that presses on a nerve root may result in lower extremity sensory and motor problems such as pain, numbness, and muscular weakness and atrophy. Bowel and bladder dysfunction are serious conditions that can result from herniated lumbar discs and require immediate medical attention. Restorative exercises to improve integrity of the low back include aerobic, flexibility, muscular strength, and endurance, and core stability.

Bicondylar joint

is an ovoid articular surface, or condyle that is received into an elliptical cavity. This permits movement in two planes, allowing flexion, extension, adduction, abduction, and circumduction.

Anterior cruciate ligament

is slightly longer and thinner than the posterior ligament

Proximal tibiofibular joint

joint of the knee, important attachment site for knee structures, typically not considered a compartment of the knee joint. Primary joint of the knee and primarily a hinge joint allowing flexion and extension; however, with it rotational component about the vertical axis its considered a bicondylar joint. Articulation of the medial and lateral femoral condyles with the medial and lateral tibial plateaus. Knee is equipped with fibrocartilage discs (menisci) that are attached to the tibial plateaus and knee joint capsules.

Ankle and foot

joints responsible for weight bearing and ambulation. Proper function and mechanics are essential for sports activities and performing daily activities of life. Slight abnormalities (muscular imblance, proprioceptive dysfunction, and structural changes) are transmitted via the kinetic chain to most joints superior to them in the body, such as knee, hip, lower back, neck, shoulder, and body alignment and postural problems.

Anterior muscles of the knee

large and powerful thigh muscles cross the knee joint, several are two-joint muscles acting on the hip joint as well. Quadriceps muscles (rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis)

Recus femoris

large, two-joint muscle that originates from the anterior inferior iliac spine (AIIS). Flexes the hip in addition to extending the knee.

peroneus longus and brevis muscles

lateral muscles that evert (stand on medial edge of foot) the foot and assist with plantarflexion

Cruciate ligaments

ligament of the knee that cross within the joint cavity between the femur and tibia and are important in maintain anterior-posterior and rotational stability at the knee

Collateral ligaments

ligaments of the knee connect the femure with the leg bones- medial collateral with the tibia and the lateral collateral with the fibula. Aid in stability of the knee, counteracting valgus and varus forces. Medial collateral ligaments attaches to the medial meniscus of the knee, but lateral collateral ligament does not attach to the lateral meniscus

Ligaments of the spine

main supporting ligaments of the spinal column are anterior and posterior longitudinal ligaments and the ligamentum flavum, span the upper cervical to the lower lumbar region. Anterior and posterior longitudinal ligaments attach to the vertebral bodies, and ligamentum flavum connects to the posterior arches and forms the posterior border of the vertebral canal. Interspinous and supraspinous ligaments attach to adjacent posterior arch structures.

Tibia

major weight-bearing bone of the leg

Lower bony structure of the spine

spinal column contains the sacrum and coccyx, situated at the lower pine, immediately inferior to the fifth lumbar vertebra. Sacrum is a large triangular bone that acts as the transition point between spine and pelvis. Coccyx bone formed of three to five fused vertebrae located at the distal sacrum.

gastrocnemius muscle

superficial posterior muscle, two-hive head and two-joint muscle, powerful plantarflexor of the ankle as well as flexor or the knee. More fast twitch fibers than the soleus. Used more during dynamic, higher-force activities, and soleus is more active during postural and static contractions. Crosses the knee and ankle, position of the knee during plantarflexion resistance exercise affects the activity of this muscle. During a calf raise, it is emphasized when knee is straight. Soleus active when knee is bent during calf raise. (when knee is bent this muscle is disengaged because it also runs through the knee, however the soleus does not run through the knee therefore it is engaged when knee is bent) pg93.

Superficial and Deep posterior ankle and foot muscles

superficial posterior muscles, gastrocnemius, soleus, and plantaris, are ankle plantarflexors

Arthrodial joint

synovial joint allowing gliding movement

Compound Trunk Extension

trunk motion in the saggital plane during normal activities lifts, fends requiring compound movement of the lumbar spine, pelvis, and hip joints. Coumpound extension or lumbopelvic rhythm. Full trunk flexion, lumbar extensors (erector spinae and multifidus) and hip extensors (gluteals and hamstrings) work together to actively rotate the trunk through apporximately 180*. Lumbar is 72*, hip and pelvis are 108*. Relative contribution of individual muscle groups to force production during compound trunk extension is unknown, but assumed large hip extensors generate most of the force. Small lumbar muscles are assumed to play minor role in trunk extension torque production due to minimal movement during bending and lifting. Isolation of lumbar spine during exercises is thought to force lumbar muscles to be the primary trunk extensors providing overload stimulus for strength gains. progressive resistance exercisers that stabilize the pelvis produce unusually large gains (+100%) in lumbar extension strength even with once a week training. Low back pain display significant improvements in symptoms, disability, and psychosocial function.

Ligament pairs of the knee

two major pairs of ligaments in the knee: cruciate and collateral ligaments

Gastrocnemius muscle

two-head and two-joint muscle that acts to flex the knee and plantarflex the ankle.

Semimembranosus and semitendinosus (medial hamstrings)

two-joint muscles that act to flex and internally rotate the knee and extend and extend and internally rotate the hip. ??? The wider (at insertion) one runs under neither the thinner muscle.

Medial meniscus

type of fibrocartilage disc that is larger, thinner, and more "C" shaped than the lateral meniscus

Medial femoral condyle knee arrangement

typically extends more distally than the lateral condyle, giving the knee a slight valgus arrangement. (knee knocking)

Popliteus

weak muscle flexor of the knee, but it "unlocks" the extended knee by laterally rotating the femur on the fixed tibia.