In anatomy , the thigh is the area between the hip ( pelvis ) and the knee . Anatomically, it is part of the lower limb .
98-421: The single bone in the thigh is called the femur . This bone is very thick and strong (due to the high proportion of bone tissue ), and forms a ball and socket joint at the hip , and a modified hinge joint at the knee. The femur is the only bone in the thigh and serves as an attachment site for all muscles in the thigh. The head of the femur articulates with the acetabulum in the pelvic bone forming
196-440: A bone experiences within long bones such as the femur . As far as short bones are concerned, trabecular alignment has been studied in the vertebral pedicle . Thin formations of osteoblasts covered in endosteum create an irregular network of spaces, known as trabeculae. Within these spaces are bone marrow and hematopoietic stem cells that give rise to platelets , red blood cells and white blood cells . Trabecular marrow
294-427: A film or similar activity. The pain is typically aching and occasionally sharp. Pain may be worsened by activities. The knee joint may exhibit noises such as clicking. However, this has no relation to pain and function. Giving-way of the knee may be reported. Reduced knee flexion may be experienced during activities. In most people with patellofemoral pain syndrome an examination of their history will highlight
392-479: A long bone are separated by a growing zone of cartilage (the epiphyseal plate ). At skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure). In the upper limbs, only the diaphyses of the long bones and scapula are ossified. The epiphyses, carpal bones, coracoid process, medial border of the scapula, and acromion are still cartilaginous. The following steps are followed in
490-509: A mineralized organic matrix. The primary inorganic component of human bone is hydroxyapatite , the dominant bone mineral , having the nominal composition of Ca 10 (PO 4 ) 6 (OH) 2 . The organic components of this matrix consist mainly of type I collagen —"organic" referring to materials produced as a result of the human body—and inorganic components, which alongside the dominant hydroxyapatite phase, include other compounds of calcium and phosphate including salts. Approximately 30% of
588-419: A more fulfilling and healthier lifestyle. Bone is constantly being created and replaced in a process known as remodeling . This ongoing turnover of bone is a process of resorption followed by replacement of bone with little change in shape. This is accomplished through osteoblasts and osteoclasts. Cells are stimulated by a variety of signals , and together referred to as a remodeling unit. Approximately 10% of
686-457: A number of anatomical terms to describe the appearance, shape and function of bones. Other anatomical terms are also used to describe the location of bones . Like other anatomical terms, many of these derive from Latin and Greek . Some anatomists still use Latin to refer to bones. The term "osseous", and the prefix "osteo-", referring to things related to bone, are still used commonly today. Some examples of terms used to describe bones include
784-422: A number of chemical enzymes that either promote or inhibit the activity of the bone remodeling cells, controlling the rate at which bone is made, destroyed, or changed in shape. The cells also use paracrine signalling to control the activity of each other. For example, the rate at which osteoclasts resorb bone is inhibited by calcitonin and osteoprotegerin . Calcitonin is produced by parafollicular cells in
882-401: A patient has mechanical symptoms like a locked knee, knee effusion , or failure to improve following physical therapy , then an MRI may give more insight into diagnosis and treatment. PFPS is one of a handful of conditions sometimes referred to as runner's knee ; the other conditions being chondromalacia patellae , iliotibial band syndrome , and plica syndrome . Chondromalacia patellae
980-452: A positive Gowers' sign on physical examination. Thigh injury resulting from sports , whether acute or from overuse , can mean significant incapacity to perform. Soft tissue injury can encompass sprains , strains , bruising and tendinitis . Runner's knee ( patellofemoral pain ) is a direct consequence of the kneecap rubbing against the end of the thigh bone ( femur ). Tight hamstrings and weak thigh muscles, required to stabilize
1078-529: A positive correlation between the adaptations of resistance training and bone density. While nutritional and pharmacological approaches may also improve bone health, the strength and balance adaptations from resistance training are a substantial added benefit. Weight-bearing exercise may assist in osteoblast (bone-forming cells) formation and help to increase bone mineral content. High-impact sports, which involve quick changes in direction, jumping, and running, are particularly effective with stimulating bone growth in
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#17327720058071176-540: A precipitating event that caused the injury. Changes in activity patterns such as excessive increases in running mileage, repetitions such as running up steps and the addition of strength exercises that affect the patellofemoral joint are commonly associated with symptom onset. Excessively worn or poorly fitted footwear may be a contributing factor. To prevent recurrence the causal behaviour should be identified and managed correctly. The cause of pain and dysfunction often results from either abnormal forces (e.g. increased pull of
1274-419: A recent study, there was a strong correlation between calcium intake and BMD across a variety of diverse populations of children and adolescence ultimately coming to the conclusion that fundamentally, achieving optimal bone health is necessary for providing our youth with the ability to undergo hormonal changes as well. They found in a study of over 10,000 children ages 8-19 that in females, African Americans, and
1372-408: A smaller number of randomly oriented collagen fibers, but forms quickly; it is for this appearance of the fibrous matrix that the bone is termed woven . It is soon replaced by lamellar bone, which is highly organized in concentric sheets with a much lower proportion of osteocytes to surrounding tissue. Lamellar bone, which makes its first appearance in humans in the fetus during the third trimester,
1470-401: A strong nutritional plan with adequate amounts of Calcium sources can lead to strong bones but also can be a worth-while strategy into preventing further damage or degradation of bone stores as we age. The connection between Calcium intake & BMD and its effects on youth as a whole is a very world-wide issue and has been shown to affect different ethnicities in a variety of differing ways. In
1568-608: A variety of doctors, including rheumatologists for joints, and orthopedic surgeons, who may conduct surgery to fix broken bones. Other doctors, such as rehabilitation specialists may be involved in recovery, radiologists in interpreting the findings on imaging, and pathologists in investigating the cause of the disease, and family doctors may play a role in preventing complications of bone disease such as osteoporosis. Patellofemoral pain Patellofemoral pain syndrome ( PFPS ; not to be confused with jumper's knee )
1666-416: A variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions . Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue , a type of specialised connective tissue . It has a honeycomb -like matrix internally, which helps to give the bone rigidity. Bone tissue
1764-456: A very low shear stress strength (51.6 MPa). This means that bone resists pushing (compressional) stress well, resist pulling (tensional) stress less well, but only poorly resists shear stress (such as due to torsional loads). While bone is essentially brittle , bone does have a significant degree of elasticity , contributed chiefly by collagen . Mechanically, bones also have a special role in hearing . The ossicles are three small bones in
1862-497: A weak quadriceps muscle . It is particularly common among runners . The diagnosis is generally based on the symptoms and examination . If pushing the kneecap into the femur increases the pain, the diagnosis is more likely. Treatment typically involves rest and rehabilitation with a physical therapist . Runners may need to switch to activities such as cycling or swimming. Insoles may help some people. Symptoms may last for years despite treatment. Patellofemoral pain syndrome
1960-618: A year. Risk factors for a prolonged recovery (or persistent condition) include age (older athletes), females, increased body weight, a reduction in muscle strength, time to seek care, and in those who experience symptoms for more than two months. Patellofemoral pain syndrome is the most common cause of anterior knee pain in the outpatient. Specific populations at high risk of primary PFPS include runners, bicyclists, basketball players, young athletes and females. BMI did not significantly increase risk of developing PFPS in adolescents. However, adults with PFPS have higher BMI than those without. It
2058-408: Is knee pain as a result of problems between the kneecap and the femur . The pain is generally in the front of the knee and comes on gradually. Pain may worsen with sitting down with a bent knee for long periods of time, excessive use, or climbing and descending stairs. While the exact cause is unclear, it is believed to be due to overuse. Risk factors include trauma, increased training, and
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#17327720058072156-441: Is mineralized tissue of two types, cortical bone and cancellous bone . Other types of tissue found in bones include bone marrow , endosteum , periosteum , nerves , blood vessels and cartilage . In the human body at birth, approximately 300 bones are present. Many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones . The largest bone in
2254-403: Is a term sometimes used synonymously with PFPS. However, there is general consensus that PFPS applies only to individuals without cartilage damage, thereby distinguishing it from chondromalacia patellae, a condition with softening of the patellar articular cartilage. Despite this distinction, the diagnosis of PFPS is typically made based only on the history and physical examination rather than on
2352-474: Is called "osteoid". Around and inside collagen fibrils calcium and phosphate eventually precipitate within days to weeks becoming then fully mineralized bone with an overall carbonate substituted hydroxyapatite inorganic phase. In order to mineralise the bone, the osteoblasts secrete alkaline phosphatase, some of which is carried by vesicles . This cleaves the inhibitory pyrophosphate and simultaneously generates free phosphate ions for mineralization, acting as
2450-418: Is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten times the surface area of compact bone. The words cancellous and trabecular refer to the tiny lattice-shaped units (trabeculae) that form the tissue. It was first illustrated accurately in
2548-533: Is effective in PFPS. There is no difference in pain symptoms between taping and non-taping in individuals with PFPS. Although taping alone is not shown to reduce pain, studies show that taping in conjunction with therapeutic exercise can have a significant effect on pain reduction. Knee braces are ineffective in treating PFPS. The technique of McConnell taping involves pulling the patella medially with tape (medial glide). Findings from some studies suggest that there
2646-453: Is found to be effective in treating PFPS. However, there is not enough evidence that supports lumbopelvic spine manipulation has any effect on the quadriceps muscle activation to improve function & reduce pain. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat PFPS; however, there is only very limited evidence that they are effective. NSAIDs may reduce pain in the short term; overall, however, after three months pain
2744-421: Is hard to isolate and strengthen only one muscle of quadriceps. Also, there is growing evidence that shows proximal factors play a much larger role than vastus medialis (VMO) strength deficits or quadriceps imbalance. Hip abductor, extensor, and external rotator strengthening may help. Emphasis during exercise may be placed on coordinated contraction of the medial and lateral parts of the quadriceps as well as of
2842-409: Is insufficient evidence to compare the effectiveness of different types of exercises with each other, and exercises with other forms of treatment. Exercise therapy is the recommended first line treatment of PFPS. Various exercises have been studied and recommended. Exercises are described according to 3 parameters: The majority of exercise programs intended to treat PFPS are designed to strengthen
2940-589: Is less common to see, the necessity for a healthy routine especially when it comes to bone development is essential in our youth. Children that naturally have lower bone mineral density have a lower quality of life and therefore lead a life that is less fulfilling and uncomfortable. Factors such as increases in Calcium intake has been shown to increase BMD stores. Studies have shown that increasing calcium stores whether that be through supplementation or intake via foods and beverages such as leafy greens and milk have pushed
3038-447: Is limited benefit with patella taping or bracing when compared to quadriceps exercises alone. There is a lack of evidence to show that knee braces, sleeves, or straps are effective. Low arches can cause overpronation or the feet to roll inward too much increasing load on the patellofemoral joint. Poor lower extremity biomechanics may cause stress on the knees and can be related to the development of patellofemoral pain syndrome, although
Thigh - Misplaced Pages Continue
3136-492: Is made up of different types of bone cells . Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralised matrix of bone tissue has an organic component of mainly collagen called ossein and an inorganic component of bone mineral made up of various salts. Bone tissue
3234-518: Is mostly found in the bone marrow of the femur, the ribs, the vertebrae and pelvic bones . Bone receives about 10% of cardiac output. Blood enters the endosteum , flows through the marrow, and exits through small vessels in the cortex. In humans, blood oxygen tension in bone marrow is about 6.6%, compared to about 12% in arterial blood, and 5% in venous and capillary blood. Bone is metabolically active tissue composed of several types of cells. These cells include osteoblasts , which are involved in
3332-527: Is necessary during our childhood as these factors lead to a supportive and healthy lifestyle/bone health. Up till the age of 30, the bone stores that we have will ultimately start to decrease as we surpass this age. Influencing factors that can help us have larger stores and higher amounts of BMD will allow us to see less harmful results as we reach older adulthood. The issue of having fragile bones during our childhood leads to an increase in certain disorders and conditions such as juvenile osteoporosis , though it
3430-552: Is not a gold standard assessment to diagnose PFPS. A variety of treatments for patellofemoral pain syndrome are available. Most people respond well to conservative therapy. Patellofemoral pain syndrome may also result from overuse or overload of the PF joint. For this reason, knee activity should be reduced until the pain is resolved. There is consistent but low quality evidence that exercise therapy for PFPS reduces pain, improves function and aids long-term recovery. However, there
3528-455: Is not fully known. Two types of bone can be identified microscopically according to the arrangement of collagen: woven and lamellar. Woven bone is produced when osteoblasts produce osteoid rapidly, which occurs initially in all fetal bones, but is later replaced by more resilient lamellar bone. In adults, woven bone is created after fractures or in Paget's disease . Woven bone is weaker, with
3626-471: Is not improved. There is no evidence that one type of NSAID is superior to another in PFPS, and therefore some authors have recommended that the NSAID with fewest side effects and which is cheapest should be used. Glycosaminoglycan polysulfate (GAGPS) inhibits proteolytic enzymes and increases synthesis and degree of polymerization of hyaluronic acid in synovial fluid. There is contradictory evidence that it
3724-403: Is not uniformly solid, but consists of a flexible matrix (about 30%) and bound minerals (about 70%), which are intricately woven and continuously remodeled by a group of specialized bone cells. Their unique composition and design allows bones to be relatively hard and strong, while remaining lightweight. Bone matrix is 90 to 95% composed of elastic collagen fibers, also known as ossein, and
3822-783: Is sometimes suggested, however the effectiveness of this treatment is not certain. Inflexibility has often been cited as a source of patellofemoral pain syndrome. Stretching of the lateral knee has been suggested to help. Knee and lumbar joint mobilization are not recommended as primary interventions for PFPS. It can be used as combination intervention, but as we continue to promote use of active and physical interventions for PFPS, passive interventions such as joint mobilizations are not recommended. Manual therapy in addition to exercises helps in reducing pain, improving function, and knee range of motion in patients with PFPS. Manual therapy such as patellar joint mobilization, manipulation and soft tissue mobilization along with physical therapy exercises
3920-417: Is still needed when using these tests to make a differential diagnosis of PFPS. Individuals with PFP may be exhibit higher pain level and lower function. Magnetic resonance imaging rarely can give useful information for managing patellofemoral pain syndrome and treatment should focus on an appropriate rehabilitation program including correcting strength and flexibility concerns. In the uncommon cases where
4018-730: Is stimulated by the secretion of growth hormone by the pituitary , thyroid hormone and the sex hormones ( estrogens and androgens ). These hormones also promote increased secretion of osteoprotegerin. Osteoblasts can also be induced to secrete a number of cytokines that promote reabsorption of bone by stimulating osteoclast activity and differentiation from progenitor cells. Vitamin D , parathyroid hormone and stimulation from osteocytes induce osteoblasts to increase secretion of RANK- ligand and interleukin 6 , which cytokines then stimulate increased reabsorption of bone by osteoclasts. These same compounds also increase secretion of macrophage colony-stimulating factor by osteoblasts, which promotes
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4116-561: Is stronger and filled with many collagen fibers parallel to other fibers in the same layer (these parallel columns are called osteons). In cross-section , the fibers run in opposite directions in alternating layers, much like in plywood , assisting in the bone's ability to resist torsion forces. After a fracture, woven bone forms initially and is gradually replaced by lamellar bone during a process known as "bony substitution". Compared to woven bone, lamellar bone formation takes place more slowly. The orderly deposition of collagen fibers restricts
4214-448: Is the osteon . Cancellous bone or spongy bone , also known as trabecular bone , is the internal tissue of the skeletal bone and is an open cell porous network that follows the material properties of biofoams . Cancellous bone has a higher surface-area-to-volume ratio than cortical bone and it is less dense . This makes it weaker and more flexible. The greater surface area also makes it suitable for metabolic activities such as
4312-454: Is the most common cause of knee pain, affecting more than 20% of young adults. It occurs about 2.5 times more often in females than males. The onset of the condition is usually gradual, although some cases may appear suddenly following trauma. The most common symptom is diffuse vague pain around the kneecap (peripatellar) and localized pain focused behind the kneecap (retropatellar). Affected individuals typically have difficulty describing
4410-400: Is uncertain. No evidence supports use of custom made foot orthoses. The scientific consensus is that surgery should be avoided except in very severe cases in which conservative treatments fail. The majority of individuals with PFPS receive nonsurgical treatment. The use of electrophysical agents and therapeutic modalities are not recommended as passive treatments should not be the focus of
4508-410: Is used in popular fashion around the world, such as thigh-high boots and zettai ryoiki . Bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells , store minerals , provide structure and support for the body, and enable mobility . Bones come in
4606-492: Is very minimal. Being able to consistently meet calcium needs while also engaging in weight-bearing exercise is essential for building a strong initial bone foundation at which to build upon. Being able to reach our daily value of 1300mg for ages 9-18 is becoming more and more necessary and as we progress in health, the chance that osteoporosis and other factors such as bone fragility or potential for stunted growth can be greatly reduced through these resources, ultimately leading to
4704-452: The cisterna chyli . The deep venous system of the thigh consists of the femoral vein , common femoral vein , deep femoral vein , the proximal part of the popliteal vein , and various smaller vessels; these are the site of proximal deep vein thrombosis . The perforating veins connect the deep and the superficial system, which consists of the small and great saphenous veins (the site of varicose veins ). Thigh weakness can result in
4802-440: The hip joint , while the distal part of the femur articulates with the tibia and patella forming the knee . By most measures, the femur is the strongest bone in the body. The femur is also the longest bone in the body. The femur is categorised as a long bone and comprises a diaphysis , the shaft (or body) and two epiphyses , the lower extremity and the upper extremity of femur , that articulate with adjacent bones in
4900-724: The middle ear which are involved in sound transduction. The cancellous part of bones contain bone marrow . Bone marrow produces blood cells in a process called hematopoiesis . Blood cells that are created in bone marrow include red blood cells , platelets and white blood cells . Progenitor cells such as the hematopoietic stem cell divide in a process called mitosis to produce precursor cells. These include precursors which eventually give rise to white blood cells , and erythroblasts which give rise to red blood cells. Unlike red and white blood cells, created by mitosis, platelets are shed from very large cells called megakaryocytes . This process of progressive differentiation occurs within
4998-479: The osteonic canal . Volkmann's canals at right angles connect the osteons together. The columns are metabolically active, and as bone is reabsorbed and created the nature and location of the cells within the osteon will change. Cortical bone is covered by a periosteum on its outer surface, and an endosteum on its inner surface. The endosteum is the boundary between the cortical bone and the cancellous bone. The primary anatomical and functional unit of cortical bone
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#17327720058075096-420: The thyroid gland , and can bind to receptors on osteoclasts to directly inhibit osteoclast activity. Osteoprotegerin is secreted by osteoblasts and is able to bind RANK-L, inhibiting osteoclast stimulation. Osteoblasts can also be stimulated to increase bone mass through increased secretion of osteoid and by inhibiting the ability of osteoclasts to break down osseous tissue . Increased secretion of osteoid
5194-448: The 12-15 adolescent groups that at 2.6-2.8g/kg of body weight, they began to see a decrease in BMD. They elaborate on this by determining that this is strongly influenced by a lower baseline in calcium intake throughout puberty. Genetic factors have also been shown to influence lower acceptance of calcium stores. Ultimately, the window that youth have for accruing and building resilient bones
5292-420: The acellular component of bone consists of organic matter, while roughly 70% by mass is attributed to the inorganic phase. The collagen fibers give bone its tensile strength , and the interspersed crystals of hydroxyapatite give bone its compressive strength . These effects are synergistic . The exact composition of the matrix may be subject to change over time due to nutrition and biomineralization , with
5390-479: The body is the femur or thigh-bone, and the smallest is the stapes in the middle ear . The Greek word for bone is ὀστέον (" osteon "), hence the many terms that use it as a prefix—such as osteopathy . In anatomical terminology , including the Terminologia Anatomica international standard, the word for a bone is os (for example, os breve , os longum , os sesamoideum ). Bone
5488-416: The bone marrow. After the cells are matured, they enter the circulation . Every day, over 2.5 billion red blood cells and platelets, and 50–100 billion granulocytes are produced in this way. As well as creating cells, bone marrow is also one of the major sites where defective or aged red blood cells are destroyed. Determined by the species, age, and the type of bone, bone cells make up to 15 percent of
5586-548: The bone matrix. The release of these growth factors from the bone matrix could cause the proliferation of osteoblast precursors. Essentially, bone growth factors may act as potential determinants of local bone formation. Cancellous bone volume in postmenopausal osteoporosis may be determined by the relationship between the total bone forming surface and the percent of surface resorption. A number of diseases can affect bone, including arthritis, fractures, infections, osteoporosis and tumors. Conditions relating to bone can be managed by
5684-429: The bone. Growth factor storage—mineralized bone matrix stores important growth factors such as insulin -like growth factors, transforming growth factor, bone morphogenetic proteins and others. Strong bones during our youth is essential for preventing osteoporosis and bone fragility as we age. The importance of insuring factors that could influence increases in BMD while lowering our risks for further bone degradation
5782-426: The breakdown of bones by the process of bone resorption . New bone is then formed by the osteoblasts. Bone is constantly remodeled by the resorption of osteoclasts and created by osteoblasts. Osteoclasts are large cells with multiple nuclei located on bone surfaces in what are called Howship's lacunae (or resorption pits ). These lacunae are the result of surrounding bone tissue that has been reabsorbed. Because
5880-458: The cartilage called "primary ossification centers". They mostly appear during fetal development, though a few short bones begin their primary ossification after birth . They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Secondary ossification occurs after birth and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphysis and both epiphyses of
5978-447: The conversion of cartilage to bone: Bone development in youth is extremely important in preventing future complications of the skeletal system. Regular exercise during childhood and adolescence can help improve bone architecture, making bones more resilient and less prone to fractures in adulthood. Physical activity, specifically resistance training, stimulates growth of bones by increasing both bone density and strength. Studies have shown
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#17327720058076076-567: The creation and mineralization of bone tissue, osteocytes , and osteoclasts , which are involved in the reabsorption of bone tissue. Osteoblasts and osteocytes are derived from osteoprogenitor cells, but osteoclasts are derived from the same cells that differentiate to form macrophages and monocytes . Within the marrow of the bone there are also hematopoietic stem cells . These cells give rise to other cells, including white blood cells , red blood cells , and platelets . Osteoblasts are mononucleate bone-forming cells. They are located on
6174-641: The differentiation of progenitor cells into osteoclasts, and decrease secretion of osteoprotegerin. Bone volume is determined by the rates of bone formation and bone resorption. Certain growth factors may work to locally alter bone formation by increasing osteoblast activity. Numerous bone-derived growth factors have been isolated and classified via bone cultures. These factors include insulin-like growth factors I and II, transforming growth factor-beta, fibroblast growth factor, platelet-derived growth factor, and bone morphogenetic proteins. Evidence suggests that bone cells produce growth factors for extracellular storage in
6272-453: The engravings of Crisóstomo Martinez . Bone marrow , also known as myeloid tissue in red bone marrow, can be found in almost any bone that holds cancellous tissue . In newborns , all such bones are filled exclusively with red marrow or hematopoietic marrow, but as the child ages the hematopoietic fraction decreases in quantity and the fatty/ yellow fraction called marrow adipose tissue (MAT) increases in quantity. In adults, red marrow
6370-534: The exact mechanism linking joint loading to the development of the condition is not clear. Foot orthoses can help to improve lower extremity biomechanics and may be used as a component of overall treatment. Foot orthoses may be useful for reducing knee pain in the short term, and may be combined with exercise programs or physical therapy. However, there is no evidence supporting use of combined exercise with foot orthoses as intervention beyond 12 months for adults. Evidence for long term use of foot orthoses for adolescents
6468-429: The exchange of calcium ions. Cancellous bone is typically found at the ends of long bones, near joints, and in the interior of vertebrae. Cancellous bone is highly vascular and often contains red bone marrow where hematopoiesis , the production of blood cells, occurs. The primary anatomical and functional unit of cancellous bone is the trabecula . The trabeculae are aligned towards the mechanical load distribution that
6566-410: The foci for calcium and phosphate deposition. Vesicles may initiate some of the early mineralization events by rupturing and acting as a centre for crystals to grow on. Bone mineral may be formed from globular and plate structures, and via initially amorphous phases. Five types of bones are found in the human body: long, short, flat, irregular, and sesamoid. In the study of anatomy , anatomists use
6664-410: The formation of bone from cartilage . Intramembranous ossification mainly occurs during formation of the flat bones of the skull but also the mandible, maxilla, and clavicles; the bone is formed from connective tissue such as mesenchyme tissue rather than from cartilage. The process includes: the development of the ossification center , calcification , trabeculae formation and the development of
6762-590: The formation of osteoid to about 1 to 2 μm per day. Lamellar bone also requires a relatively flat surface to lay the collagen fibers in parallel or concentric layers. The extracellular matrix of bone is laid down by osteoblasts , which secrete both collagen and ground substance. These cells synthesise collagen alpha polypetpide chains and then secrete collagen molecules. The collagen molecules associate with their neighbors and crosslink via lysyl oxidase to form collagen fibrils. At this stage, they are not yet mineralized, and this zone of unmineralized collagen fibrils
6860-475: The groundwork for bone health later in life, reducing the risk of bone-related conditions such as osteoporosis. Bones have a variety of functions: Bones serve a variety of mechanical functions. Together the bones in the body form the skeleton . They provide a frame to keep the body supported, and an attachment point for skeletal muscles , tendons , ligaments and joints , which function together to generate and transfer forces so that individual body parts or
6958-400: The hip adductor, hip abductor and gluteal muscles. Many exercise programs include stretches designed to improve lower limb flexibility. Electromyographic biofeedback allows visualization of specific muscle contractions and may help individuals performing the exercises to target the intended muscles during the exercise. Neuromuscular electrical stimulation to strengthen quadricep muscles
7056-402: The hip and knee. In cross-section, the thigh is divided up into three separate compartments, divided by fascia , each containing muscles. These compartments use the femur as an axis and are separated by tough connective tissue membranes (or septa ). Each of these compartments has its own blood and nerve supply, and contains a different group of muscles . Anterior compartment muscles of
7154-442: The knee, increase the risk of developing of runner's knee. Western societies generally tolerate clothing that displays thighs, such as short shorts and miniskirts . Beachwear and many athleisure styles often display thighs as well. Professional dress codes may require covering up bare thighs. Many Islamic countries disapprove of or prohibit the display of thighs, especially by women. Strategic covering or display of thighs
7252-417: The lateral quadriceps retinaculum with acute or chronic lateral patellofemoral subluxation/dislocation) or prolonged repetitive compressive or shearing forces (running or jumping) on the patellofemoral joint. The result is synovial irritation and inflammation and subchondral bony changes in the distal femur or patella known as "bone bruises". The medical cause of PFPS is thought to be increased pressure or on
7350-487: The location of the pain. They may place their hands over the anterior patella or describe a circle around the patella. This is often called the "circle sign". Pain is usually initiated when weight is put on the knee extensor mechanism, such as when ascending or descending stairs or slopes, squatting, kneeling, cycling, or running. Pain during prolonged sitting is sometimes termed the "movie sign" or "theatre sign" because individuals might experience pain while sitting to watch
7448-406: The major muscles of the thigh are the largest muscles of the body, resistance exercises (strength training) of them stimulate blood flow more than any other localized activity. The arterial supply is by the femoral artery and the obturator artery . The lymphatic drainage closely follows the arterial supply and drains to the lumbar lymphatic trunks on the corresponding side, which in turn drains to
7546-487: The notion that prepuberty or even early pubertal children will see increases in BMD with the addition of increase Calcium intake. Another research study goes on to show that long-term calcium intake has been proven to significantly contribute to overall BMD in children without certain conditions or disorders. This data shows that ensuring adequate calcium intake in children reinforces the structure and rate at which bones will begin to densify. Further detailing how structuring
7644-478: The osteoblast puts up collagen fibers. These collagen fibers are used as a framework for the osteoblasts' work. The osteoblast then deposits calcium phosphate which is hardened by hydroxide and bicarbonate ions. The brand-new bone created by the osteoblast is called osteoid . Once the osteoblast is finished working it is actually trapped inside the bone once it hardens. When the osteoblast becomes trapped, it becomes known as an osteocyte. Other osteoblasts remain on
7742-502: The osteoclasts are derived from a monocyte stem-cell lineage, they are equipped with phagocytic -like mechanisms similar to circulating macrophages . Osteoclasts mature and/or migrate to discrete bone surfaces. Upon arrival, active enzymes, such as tartrate-resistant acid phosphatase , are secreted against the mineral substrate. The reabsorption of bone by osteoclasts also plays a role in calcium homeostasis . Bones consist of living cells (osteoblasts and osteocytes) embedded in
7840-456: The osteocyte cell processes occupy channels called canaliculi. The many processes of osteocytes reach out to meet osteoblasts, osteoclasts, bone lining cells, and other osteocytes probably for the purposes of communication. Osteocytes remain in contact with other osteocytes in the bone through gap junctions—coupled cell processes which pass through the canalicular channels. Osteoclasts are very large multinucleate cells that are responsible for
7938-444: The patellar apprehension test, which is deemed positive when there is pain or discomfort associated with lateral translation of the patella. Various clinical tests have been investigated for diagnostic accuracy. The Active Instability Test, knee pain during stair climbing, Clarke's test, pain with prolonged sitting, patellar inferior pole tilt, and pain during squatting have demonstrated the best accuracy. However, careful consideration
8036-637: The patellofemoral joint. There are several theorized mechanisms relating to how this increased pressure occurs: Patellofemoral pain syndrome can also result from fractures/trauma, internal knee derangement, osteoarthritis of the knee, and bony tumors in or around the knee. People can be observed standing and walking to determine patellar alignment. The Q-angle , lateral hypermobility, and J-sign are commonly used to determine patellar maltracking. The patellofemoral glide, tilt, and grind tests ( Clarke's sign ), when performed, can provide strong evidence for PFPS. Lastly, lateral instability can be assessed via
8134-427: The periosteum. Endochondral ossification occurs in long bones and most other bones in the body; it involves the development of bone from cartilage. This process includes the development of a cartilage model, its growth and development, development of the primary and secondary ossification centers , and the formation of articular cartilage and the epiphyseal plates . Endochondral ossification begins with points in
8232-409: The plan of care. There is no evidence to support the use of acupuncture or low-level laser therapy . Most studies claiming benefits of alternative therapies for PFPS were conducted with flawed experimental design, and therefore did not produce reliable results. Patellofemoral pain syndrome can become a chronic injury, with an estimated 50% of people reporting persistent patellar-femoral pain after
8330-434: The quadriceps muscles, because their weakness and quadriceps muscle imbalance may contribute to abnormal patellar tracking. If the strength of the vastus medialis muscle is inadequate, the usually larger and stronger vastus lateralis muscle will pull sideways (laterally) on the kneecap. Strengthening the vastus medialis to prevent or counter the lateral force of the vastus lateralis is one way of relieving PFPS, however it
8428-684: The ratio of calcium to phosphate varying between 1.3 and 2.0 (per weight), and trace minerals such as magnesium , sodium , potassium and carbonate also be found. Type I collagen composes 90–95% of the organic matrix, with the remainder of the matrix being a homogenous liquid called ground substance consisting of proteoglycans such as hyaluronic acid and chondroitin sulfate , as well as non-collagenous proteins such as osteocalcin , osteopontin or bone sialoprotein . Collagen consists of strands of repeating units, which give bone tensile strength, and are arranged in an overlapping fashion that prevents shear stress. The function of ground substance
8526-462: The remainder is ground substance . The elasticity of collagen improves fracture resistance. The matrix is hardened by the binding of inorganic mineral salt, calcium phosphate , in a chemical arrangement known as bone mineral , a form of calcium apatite . It is the mineralization that gives bones rigidity. Bone is actively constructed and remodeled throughout life by special bone cells known as osteoblasts and osteoclasts. Within any single bone,
8624-558: The results of any medical imaging. Therefore, it is unknown whether most persons with a diagnosis of PFPS have cartilage damage or not, making the difference between PFPS and chondromalacia theoretical rather than practical. It is thought that only some individuals with anterior knee pain will have true chondromalacia patellae. The diagnosis of patellofemoral pain syndrome is made by ruling out patellar tendinitis , prepatellar bursitis , plica syndrome , Sinding-Larsen and Johansson syndrome , and Osgood–Schlatter disease . Currently, there
8722-578: The skeletal mass of an adult is remodelled each year. The purpose of remodeling is to regulate calcium homeostasis , repair microdamaged bones from everyday stress, and to shape the skeleton during growth. Repeated stress, such as weight-bearing exercise or bone healing, results in the bone thickening at the points of maximum stress ( Wolff's law ). It has been hypothesized that this is a result of bone's piezoelectric properties, which cause bone to generate small electrical potentials under stress. The action of osteoblasts and osteoclasts are controlled by
8820-469: The surface of osteon seams and make a protein mixture known as osteoid , which mineralizes to become bone. The osteoid seam is a narrow region of a newly formed organic matrix, not yet mineralized, located on the surface of a bone. Osteoid is primarily composed of Type I collagen . Osteoblasts also manufacture hormones , such as prostaglandins , to act on the bone itself. The osteoblast creates and repairs new bone by actually building around itself. First,
8918-450: The term "foramen" to describe a hole through which something passes, and a "canal" or "meatus" to describe a tunnel-like structure. A protrusion from a bone can be called a number of terms, including a "condyle", "crest", "spine", "eminence", "tubercle" or "tuberosity", depending on the protrusion's shape and location. In general, long bones are said to have a "head", "neck", and "body". When two bones join, they are said to "articulate". If
9016-459: The thigh include sartorius , and the four muscles that comprise the quadriceps muscles – rectus femoris , vastus medialis , vastus intermedius and vastus lateralis . Posterior compartment muscles of the thigh are the hamstring muscles , which include semimembranosus , semitendinosus , and biceps femoris . Medial compartment muscles are pectineus , adductor magnus , adductor longus and adductor brevis , and also gracilis . Because
9114-419: The tissue is woven into two main patterns, known as cortical and cancellous bone, each with a different appearance and characteristics. The hard outer layer of bones is composed of cortical bone , which is also called compact bone as it is much denser than cancellous bone. It forms the hard exterior (cortex) of bones. The cortical bone gives bone its smooth, white, and solid appearance, and accounts for 80% of
9212-417: The top of the new bone and are used to protect the underlying bone, these become known as bone lining cells. Osteocytes are cells of mesenchymal origin and originate from osteoblasts that have migrated into and become trapped and surrounded by a bone matrix that they themselves produced. The spaces the cell body of osteocytes occupy within the mineralized collagen type I matrix are known as lacunae , while
9310-412: The total bone mass of an adult human skeleton . It facilitates bone's main functions—to support the whole body, to protect organs, to provide levers for movement, and to store and release chemical elements, mainly calcium. It consists of multiple microscopic columns, each called an osteon or Haversian system. Each column is multiple layers of osteoblasts and osteocytes around a central canal called
9408-418: The two bones have a fibrous connection and are relatively immobile, then the joint is called a "suture". The formation of bone is called ossification . During the fetal stage of development this occurs by two processes: intramembranous ossification and endochondral ossification . Intramembranous ossification involves the formation of bone from connective tissue whereas endochondral ossification involves
9506-430: The whole body can be manipulated in three-dimensional space (the interaction between bone and muscle is studied in biomechanics ). Bones protect internal organs, such as the skull protecting the brain or the ribs protecting the heart and lungs . Because of the way that bone is formed, bone has a high compressive strength of about 170 MPa (1,700 kgf/cm ), poor tensile strength of 104–121 MPa, and
9604-421: The youth. Sports such as soccer, basketball, and tennis have shown to have positive effects on bone mineral density as well as bone mineral content in teenagers. Engaging in physical activity during childhood years, particularly in these high-impact osteogenic sports, can help to positively influence bone mineral density in adulthood. Children and adolescents who participate in regular physical activity will place
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