T
tachypnoea rapid breathing. In most situations when ventilation increases, there is normally an increase in both depth and frequency of breathing. Increase in frequency alone may occur in response to sudden immersion in cold water, and also can accompany anxiety. Tachypnoea with shallow breathing may increase only the dead space ventilation (as in panting) and so may not affect gas exchange.
taping the use of tape to prevent or treat injury. Taping is used to limit movements which would exacerbate the injury, whilst not inhibiting function. There is a lack of scientific evidence on its use to prevent injury, but it is widely used in the treatment of conditions such as ankle sprains and patellofemoral pain.
target heart rate heart rate (HR) range aspired to during aerobic training, with view to enhancing cardiovascular fitness. Always best set in relation to the individual’s measured maximal heart rate (HRmax) or heart rate reserve (HRR), rather than general population figures. In exercise for health, 60–85% HRmax or 55–80% HRR may typically be prescribed.
tarsal tunnel syndrome common, painful foot condition, caused by compression of the posterior tibial nerve as it passes through the tarsal tunnel on the inner side of the ankle to the foot. Results in pain, numbness, burning and tingling along the sole of the foot towards the first three toes. Often the result of excessive pronation. Treatment aims to reverse the cause but surgery may be required.
tarsus the back half of the foot, containing the seven tarsal bones.
task involvement a state in which the individual’s goal is to demonstrate mastery of a task or personal improvement relative to self-referenced criteria, such as improving on their previous personal best. adj task-involved. See also ego involvement, learning goal.
task orientation a dispositional tendency to feel most successful in an activity when one demonstrates ability relative to one’s self and personal improvement rather than in comparison to the performance of others. See also ego orientation, goal orientation.
team cohesion see group cohesion.
telemetry literally ‘measurement at a distance’. Achieved by portable radio transmitter sending data measured from the subject to the observer’s receiver. In exercise physiology, these data invariably include heart rate (HR); more sophisticated (but bulkier) equipment will also report other values, e.g. oxygen consumption.
tendon a band of white fibrous connective tissue that joins muscle to bone. Tendons consist of parallel bundles of collagen with little elastic tissue. This results in excellent mechanical strength but little elasticity. Tendons focus the strength of muscle contraction on a relatively small area of bone, maximizing pull and facilitating movement of the bone. paratendon the fibrous sheath around a tendon, with a thin synovial lining.
tendon jerk reflex rapid reflex contraction of a muscle in response to a sudden stretch, elicited by tapping its tendon, and involving direct (monosynaptic) excitation of alpha motor neurons in the spinal cord by afferent fibres from primary sensory endings in muscle spindles. The best known is the knee jerk: when the patellar tendon is tapped, the quadriceps is caused to contract. Similar rapid monosynaptic reflexes operate, e.g. when the tendon of the biceps is tapped at the elbow or the Achilles tendon at the ankle. Also known as a phasic stretch reflex. See also stretch reflex.
tendonitis inflammation of a tendon. Usually the result of repetitive overuse movements, especially at high intensity. This causes micro-tears in the collagen matrix with inflammation, swelling, tenderness and pain, especially on specific movements. More common in older athletes. Treatment aims to identify and reverse the cause, together with local anti-inflammatory measures such as RICE, anti-inflammatory medication, electrotherapy and occasionally corticosteroid injection (into the paratendon to avoid tendon rupture). See also tenosynovitis.
tenosynovitis inflammation of the thin synovial lining of a tendon sheath, as distinct from its outer fibrous sheath. It may be caused by mechanical irritation or by bacterial infection.
tension force with which a body or object resists extension. Also known as tension load.
testis the male gonad, the site of spermatogenesis, whence sperm are discharged via the vas deferens into the urethra at ejaculation. This and also testicular endocrine function (secretion of testosterone and related hormones) are under the control of gonadotrophic hormones from the anterior pituitary, and in turn of the hypothalamus.
testosterone see anabolic steroids, testis.
tetanus disease caused by the bacterium Clostridium tetani, an anaerobic spore-forming micro-organism present in the intestines of domestic animals and humans and commonly found in soil, dust and manure. Potentially the most serious of all sports-related infections due to the presence of the spores in many sports fields. Important in sports where the athlete comes into contact with soil (e.g. grass pitches); cuts and grazes can not only allow entry of the bacteria but also facilitate their growth and neurotoxin production. Active immunization with tetanus toxoid (TT) is available as part of routine programmes, as regular booster doses and when risk is increased.
tetany condition of muscular hyperexcitability in which mild stimuli produce cramps and muscle spasms in the hands and feet (carpopedal spasm). It is due to a reduction in ionized calcium levels in the blood, for example as a result of hypoparathyroidism, or in healthy people as a result of alkalosis from alkali ingestion or hyperventilation (which may be seen in sport).
theory of planned behaviour an extension to the theory of reasoned action which incorporates the construct of perceived behavioural control, these being a person’s beliefs about whether or not they possess the necessary skills and resources to overcome any difficulties in engaging in the behaviour.
theory of reasoned action a social cognitive theory of the relationships between attitudes and volitional behaviour which holds that intention is the immediate determinant of behaviour and that intentions are determined jointly by attitudes towards the behaviour and perceived social pressures to engage in the behaviour.
thiamine (vitamin B1) see vitamins; appendix 4.2.
thick filaments see myofibrils, myosin.
thin filaments see actin, myofibrils.
thirst sensation arising when there is body fluid depletion, in response to increase in local osmolality in the hypothalamus and to neural and hormonal signals related to decreased blood volume and/or blood pressure; accompanied by production by cells in the hypothalamus of the water-retaining antidiuretic hormone (ADH) and its release from the posterior pituitary.
thoracic breathing inhalation by expanding the thorax, using the intercostal muscles to elevate the ribs, as compared to abdominal breathing using the diaphragm.
thorax the chest. thoracic cage the framework (ribs, costal cartilages, sternum and thoracic vertebrae) which protects the internal thoracic structures (especially lungs and heart) and provides attachment for muscles. Traumatic damage in sport can range from local discomfort to fractured ribs and potential damage to the lungs and, rarely, the heart. The liver and spleen, although not in the thorax, are also protected by the lower ribs and can be damaged by their injury. See also pneumothorax; appendix 1.3 fig 4.
thought stopping a technique of cognitive behaviour therapy in which individuals are trained to stop intrusive negative thoughts when they occur, either by the self-administration of a painful stimulus, such as snapping an elastic band worn around the wrist, or by bringing to mind a vivid mental image such as a stop sign. Typically, individuals are also trained to reframe the negative thoughts or replace them with positive self-talk. Sometimes known as thought stoppage.
thresholds see metabolic and related thresholds.
thrust force that propels a body or object in the required direction of motion. See also propulsive force.
thyroid gland the gland in the front of the neck which secretes the iodine-containing hormones thyroxine (T4) and triiodothyronine (T3) necessary for normal growth in childhood, and crucial in the control throughout life of energy metabolism. The hormones target most body cells (except in the CNS) where they modify enzyme synthesis, thereby controlling the rate of aerobic metabolism and heat production. Thus overactivity (hyperthyroidism) causes increase in BMR and body temperature with weight loss, and deficiency (hypothyroidism) the reverse. Regulated by thyrotrophic hormone from the anterior pituitary, and in turn by the hypothalamus. Also secretes calcitonin which acts to decrease blood [Ca2+]. See also hormones, parathyroid glands; appendix 5.
tibia the shin bone, the larger of the two bones of the lower leg; articulates above with the femur in the knee joint, below with the talus in the ankle joint, and at the outer side of its upper and lower ends with the fibula. See appendix 1.2 figs 1-3.
tibialis muscles occupy the anterior and posterior compartments of the lower leg with tendons extending into the foot: tibialis anterior (dorsiflexion) and posterior (plantarflexion and inversion). Acute inflammation, usually the result of overuse, results in the so-called tibialis syndrome where swelling in the tight compartment causes pain and tenderness on specific movements. Treatment is of the inflammation and of any identified cause such as overpronation. See also compartment syndrome.
tidal volume see lung volumes, ventilation.
time-to-event paradigm in sport psychology, a research paradigm for manipulating the components of anxiety or examining their relationships with other variables based on the reliable observation that cognitive and somatic anxiety tend to dissociate during the period leading up to a competitive event. Cognitive anxiety tends to be high and stable during the days leading up to an event and then falls when the event begins, whereas somatic anxiety remains low and stable during the days leading up to an event, rises just before the start of the event, and falls once the event begins.
torque–angular velocity relation obtained from a series of measurements of the two parameters on an isokinetic dynamometer; the nearest approximation to a muscle force–velocity relationship which can be obtained from an intact limb but falling short of exact fit, both inevitably, because no anatomical joint retains constant geometry throughout its range of movement, and also often for neurophysiological reasons, as voluntary muscle activation varies with shortening velocity, a feature which is particularly marked in knee extension. See also moment of force, momentum.
torsion force applied to a body or object that deforms (or tends to deform) it in a ‘twisting’ manner. Also known as torsion load.
total lung capacity (TLC) see lung volumes.
trait an enduring individual behavioural characteristic or aspect of personality that is exhibited in a wide range of contexts.
trajectory the plotted path of an object through space.
transcutaneous electrical nerve stimulation (TENS) a method of non-invasive pain control using pads placed either side of the spine to apply a mild electric current from a battery-operated device, which can be controlled by the patient for pain relief. Used for the control of both acute and chronic pain. Suggested to work through either blocking ‘pain’ nerves by stimulating other nerve channels or by endorphin release. Useful in sports injuries as an adjunct to other treatments, especially if drug treatment options are limited by doping regulations.
transfer of learning the extent to which practice or learning of one skill influences the learning or performance of a different skill, or the same skill in a different context. Also known as generalizability of learning. See also negative transfer, positive transfer.
translation movement from one position to another along a straight or curved line (rectilinear or curvilinear motion). translational adj.
transverse plane a plane perpendicular to the long axis of a body or object dividing it (e.g. the human body) into upper and lower parts. See also planes.
trapezius large, triangular, superficial muscle on each side of the upper back, its origin extending in the midline from the base of the skull down to the spine of the lowest thoracic vertebra. From there its fibres converge towards the shoulder, and partly over it, round the side of the lower neck, to be inserted in a continuous line into the outer end of the clavicle and the spine of the scapula. The tone of the two muscles keeps the shoulders braced and they act with the scapular spine as a lever when lifting the arms at the shoulder. See appendix 1.2 fig 5.
traveller’s diarrhoea infectious illness common where hygiene conditions are poor and caused by a variety of infectious agents. Seen in sport where teams travel to countries where food and water hygiene and sanitation are poor. Can be passed from one member to another quickly, limiting numbers available to compete.
Trendelenburg sign test of hip stability, especially of hip abductors that maintain the horizontal position of the pelvis. Normally when one leg is raised in a standing position, the pelvis tilts upwards on that side, but downwards if the abductors on the opposite side are weak. Used in sport in biomechanical assessment of lower limb conditions.
triacylglycerol (TG) the officially approved term to replace the older but still widely used triglyceride. A hydrophobic compound made from the combination of glycerol and three fatty acids, which is the major energy store of the body and main component of dietary fat. Present in the body in adipose tissue, in the circulating blood and as intramuscular triacylglycerol (IMTG). See also lipoproteins, medium-chain triglycerides.
tricarboxylic cycle see Krebs cycle.
triceps the major extensor muscle of the elbow, and the only muscle on the back of the upper arm. Arises partly from the scapula below the shoulder joint but the main bulk from the back of the humerus. Forms a broad tendon which passes behind the elbow joint (separated from it by a small bursa) to be inserted on the back of the olecranon process of the ulna. See appendix 1.2 fig 5B.
trigger finger a condition in which the finger can be actively bent but cannot be straightened without help; usually due to tenosynovitis of the flexor tendon sheath resulting in thickening or nodules which prevent free gliding. Seen particularly in gripping sports such as climbing. Treatment is by local corticosteroid injection or surgical release.
trigger point a localized hypersensitive band of tissue which, when irritated, refers pain to another part of the body. For example, shoulder trigger point resulting in headache.
triglyceride (TG) see triacylglycerol (TG).
trochanteric bursitis pain over the greater trochanter – the bony prominence on the femur on either side of the thigh. Caused by inflammation of the bursa between the bone and the overlying muscle. Occurs as a result of repeated friction due to poor running gait or technique, altered biomechanics or poor muscle co-ordination. Management is as for bursitis elsewhere, including analgesia and identification of the underlying cause.
troponin and tropomysin the control proteins, components of the thin filaments in striated muscle, that work in partnership. Troponin has high affinity for calcium ions, which are released into the cytoplasm from the sarcoplasmic reticulum in response to excitation. When ionized calcium (Ca2+) binds to it, the troponin molecule changes shape and in so doing, is thought to move the associated tropomyosin molecule around the thin filament, making previously masked binding sites on a number of actin molecules accessible to the head-groups of myosin. The resultant myosin/actin interaction then develops force. See also myofibrils.
tryptophan see amino acids, serotonin.
t-tubes (t-tubules) in full transverse tubules. Tubules continuous with the surface membrane of a striated muscle fibre, which contain extracellular fluid yet penetrate in a network pattern the whole cellular cross-section, encircling every myofibril. The tubules are separated from the sarcoplasmic reticulum (SR) only by closely adjoining membranes, and are the route of excitation as an action potential spreads inward from the surface of the fibre to instigate Ca2+ release from the SR.
turbulent flow the flow of a medium (e.g. air or water) in which the molecules are moving in a random, non-ordered manner. Can be an effect of an object or body travelling through the medium.
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