I | Basicmedical Key

Muscle group	Action (hold for 5–10 seconds; repeat ×5, three times a day)
Hip abductor	Stand erect, legs straight, feet together; stretch trunk (on frontal plane) towards the unaffected leg
Iliotibial band	Lie on a bench on the unaffected side, with the unaffected hip and knee slightly flexed, in order to maintain balance; flex the affected hip and straighten the affected knee so that the affected leg hangs off the bench; allow the iliotibial band of the affected leg to be stretched by gravitational pull Lie on a bench on the affected side with the affected leg in line with the body and the hip and knee locked; flex the unaffected (upper) leg; place the hands on the bench immediately under the shoulder and push the trunk upwards as far as possible to apply stretch to the lateral area of the affected leg
Upper iliotibial band	Stand erect; with affected leg behind normal leg; stretch trunk (on frontal plane) towards unaffected side
Lower iliotibial band	Stand erect as above, with the knee of the affected leg slightly flexed and hips rotated (on transverse plane) towards affected leg; stretch trunk (on frontal plane) towards the unaffected side
Iliotibial band and hamstrings	Stand erect, with the affected leg behind the normal leg so that the knee of the affected leg rests on the posterior aspect of the non-affected knee; rotate the trunk (on transverse plane) away from the affected leg and attempt to touch the heel of the affected leg

iliotibial band syndrome; ITBS; iliotibial band friction syndrome; ITBFS see syndrome, iliotibial band (Table I2)

Table I2 Treatment regime for iliotibial band syndrome

	Visit	Action
1	Examination Including Nobel’s and Ober’s tests, and excluding other causes of knee joint pain Gait analysis – walking and running	Check for presence of tibial varum, tibial torsion, uncompensated rearfoot varus and limb length discrepancy (include shoe wear pattern) Instigate the iliotibial band stretching regime (see Table I1), with a quadriceps- and adductor-strengthening programme Ice massage to painful area at lateral aspect of knee Advise reduction in athletic activity
2	Commence physical therapies, e.g. cortisone iontorphoresis or ultrasound and ice massage	Stabilizing orthoses and/or foot and ankle taping, ± heel lift Continue stretching programme ± massage Non-steroidal anti-inflammatory (10-day course of 400 mg ibuprofen qds) Stop all athletic activity if pain does not resolve
3	Magnetic resonance imaging/computed tomographic scan to knee joint area	Refer to orthopaedics

Most cases will resolve with one treatment; more severe cases will require a second visit and some will require orthopaedic referral.

Ilizarov frame; Ilizarov apparatus circumferential, cage-like, external fixation frame that allows ambulation during fracture healing; has also been used to achieve limb lengthening, limb length equality and to preserve normal bony architecture during healing period of Charcot neuroarthropathy

ILS see immediate life support; the management of a collapsed casualty until the arrival of the cardiac arrest team, and participation in that team, by assisting with cardiopulmonary resuscitation, simple airway management, safe defibrillation, etc

ILVEN; inflammatory linear verrucose epidermal naevi see epidermal naevi

imidazoles group of topical and systemic broad-spectrum anti-fungal agents; used to treat yeast and dermatophyte infections; see clotrimazole; econazole; ketoconazole; miconazole; and Table A13

IMIDs see disease, immune-mediated inflammatory

immediate hypersensitivity see allergic reactions

immersion foot; trench foot skin maceration, and overall deterioration of skin integrity and function due to prolonged immersion; cold-water immersion causes reduced perfusion of superficial tissues, mottling/pallor, numbness, ulceration and even ischaemic gangrene; warm-water immersion causes painful maceration, with blisters and superficial opportunistic infections

immiscible non-dissolution of one medium in another, e.g. oil in water

immobilization imposed loss of motion to promote rest, reduce oedema, encourage tissue healing and prevent tissue movement; achieved by padding/strapping/taping, elastic bandage, walking casts or non-removable casting, use of walking aids (e.g. crutches) or bed rest (see fixation)

immune-mediated inflammatory diseases; IMIDs see disease, immune-mediated inflammatory

immunity disease resistance

acquired immunity resistance induced by previous exposure to an infectious agent/antigen

active acquired immunity induced by a naturally acquired infection or by intentional vaccination

passive acquired immunity transference of antibodies from another person or animal, either naturally (e.g. from mother to fetus), or artificially (e.g. inoculation)

cellular immunity; cell-mediated immunity see syndrome, acquired immunodeficiency; AIDS

humoral immunity immunity induced by circulating antibodies

innate immunity; inherent immunity; natural immunity racial/familial immunity without previous exposure to the disease agent

immunoassay detection and assay of serum antigenic agents by antibody titre

immunocompromise reduced immunological response due to immunodeficiency disorder or immunosuppressive agents

immunodeficiency condition resulting from a defective immune response

non-specific immunodeficiency defect in non-specific immune system

primary immunodeficiency immune system defect

secondary immunodeficiency concomitant disease-induced

specific immunodeficiency B- and/or T-lymphocyte defect

immunoglobulin; Ig; antibody structurally related proteins (two pairs of polypeptide chains linked by disulphide bond, as one pair of light (L) and one pair of heavy (H) chains, classified (as immunoglobulin (Ig) G, IgA, IgM, IgD and IgE) by heavy-chain structure and antigenic properties

immunomodulator drugs immune response-modifying agents, e.g. penicillamine; used to treat recalcitrant rheumatoid disease (e.g. patients who remain symptomatic on high-dose corticosteroids)

immunosuppression chemical, pharmacological, physical or immunological suppression of the normal response to foreign material (e.g. microorganisms, donor tissue)

immunosuppressive drugs agents (e.g. azathioprine, cyclophosphamide, corticosteroids) used primarily to prevent donor tissue rejection, chronic inflammatory and autoimmune diseases

immunotherapies pharmaceutical agents that mimic natural immunological agents (e.g. antitumour necrosis factor [anti-TNF]) to control severe, aggressive or non-responsive rheumatoid and autoimmune diseases

impacted fracture see Table C18

impermeable preventing fluid passage through membranes

impetigo highly contagious, superficial staphylococcal or streptococcal skin infection; characterized by inflammatory, pruritic vesicles filled with clear yellow fluid (forms crusts when blisters rupture)

implant indwelling prosthetic (e.g. joint replacement)

impression negative imprint of foot in semirigid foam, dental impression material, or plaster of Paris bandage

impulse nerve action potential

IMS see industrial methylated spirit

Inadine povidone-iodine-impregnated medicated wound dressing (see Table D10)

incidence number of new disease cases, within a defined population, within a specific time period (contrast with prevalence)

incision atraumatic, intentional surgical division of skin and subcuticular tissues, oriented along Langer’s lines

inclination leaning toward/away from a reference point

inclusion body extraneous (e.g. viral) material within cell cytoplasm or nucleus

inclusion cyst; epithelial pearl small dermal or subdermal inflammatory lesion induced by epithelial cells encysted within deeper tissues (e.g. by poor injection or suture techniques)

incompatible combinations of clinical medicaments Table I3 and Table N7

Table I3 Incompatibilities of clinical medicaments

Physical incompatibility

Oils and water
Compound tincture of benzoin (TBCo) and water

Chemical incompatibility

Neutralization
(e.g. salicylic acid and sodium bicarbonate)
Inhibition
(e.g. adrenaline with alkalis/hydrogen peroxide, iron salts; cetrimide or chlorhexidine with soap; iodine with chloroxylenol or starch)
Formation of an inactive precipitate
(e.g. silver nitrate with sodium chloride or potassium iodide; benzoic acid with ferric chloride; ferric chloride with iodine preparations, salicylic acid or tannic acid; sodium chloride with iodine preparations)
Formation of a toxic substance
(e.g. mercury salts and iodine)
Formation of an explosive substance
(e.g. potassium permanganate with organic solvents; nitric acid with glycerin)

incongruence unequal loading across articular cartilage and/or epiphyseal plate (e.g. subluxation, predisposing bone remodelling and osteoarthrosis (see Table B6)

inconstant variable; irregular, e.g. accessory bone; adventitious bursa

incoordination absence of normal muscular coordination, e.g. ataxia

incretins hormones (produced by gut tissue in response to oral glucose intake) stimulating insulin secretion (from pancreatic beta cells); they suppress pancreatic alpha cells, increase satiety/suppress appetite, and decrease rate of stomach emptying; essential to glucose homoeostasis; deficient in diabetes mellitus (see exenatide)

incubation period time period between contact with an infectious agent and clinical manifestation of disease

index ratio of one measurable value to another, e.g. body mass index (BMI)

indicator colour-reacting reagent, indicating presence and concentration of certain factors, e.g. Clinistix

indirect transmission of infection transfer of infection via air or fomites (i.e. > 2 metres distance)

indium₁₁₁ radioactive isotope injected intravenously (i.e. nuclear imaging technique) to aid diagnosis of osteomyelitis and soft-tissue foot infections

indolent non-active; static

indometacin non-steroidal anti-inflammatory drug used to control pain and moderate/severe inflammation in rheumatoid disease and other acute musculoskeletal disorders, including acute gout

indurated; indurated oedema woody fibrosis of soft tissues, secondary to long-standing pathology (see Table O1)

industrial methylated spirit; IMS 70% fast-acting, short-duration surface antiseptic; 19:1 mix of ethanol and wood naphtha; a vehicle for an active medicament; e.g. 0.05% chlorhexidine in IMS

inert without pharmacological/therapeutic action

inertia inactivity; lack of spontaneous movement; e.g. a physical body resists movement from its position of rest until its inertia is overcome by greater external forces

infancy from birth to 2 years of age

infant foot foot during infancy which is deformable by external pressure; e.g. from short or tight ‘all-in-one’ garments; mild congenital foot deformities can be reduced by therapeutic strapping during infancy

infarct area of tissue necrosis caused by infarction

infarction area of microscopic or macroscopic tissue necrosis caused by sudden arterial or venous insufficiency, secondary to embolus, thrombus, vascular torsion or local pressure

cerebral infarction; CI cerebral hemisphere infarction, secondary cerebral artery occlusion, i.e. stroke

myocardial infarction; MI heart muscle infarction, secondary to coronary artery occlusion, i.e. heart attack

infected arthritis; septic arthritis acute bacterial monoarthritis, caused by contiguous spread of local soft-tissue infection, bone surgery or blood-borne spread of infection (e.g. from an infected tooth), especially affecting the immunocompromised (e.g. diabetes or rheumatoid arthritis)

infection invasion and multiplication of microorganisms or parasites within tissue; signs of infection are masked in subclinical infection, or the immunocompromised; Table I4; see sepsis; Table N5

Table I4 Strategies to control and eliminate infection

Strategy	Examples of actions
Elimination of sources and reservoirs of infection	Care with exposure of infected lesions to avoid cross-contamination to adjacent tissues or the environment Use of appropriate disposable barrier clothing Decontamination of instruments following a recognized protocol Thorough hand-cleansing routines and the use of disposable gloves, especially if there are any cuts or infections on the clinician’s hands Avoiding patient contact if the clinician shows signs of infection Maintaining personal vaccination programmes Thorough cleaning of all parts of the clinical environment, appropriate disposal of clinical waste and elimination of chronically wet areas (such as soap dishes)
Disruption of routes of transmission	Frequent and regular decontamination of all: Hand-held equipment by scrubbing under running water or by immersion in an ultrasonic cleaning bath followed by exposure to pressurized steam by processing through an autoclave (immersion in disinfecting solutions and exposure to heat are no longer considered adequate) Large items of equipment by washing with water and detergent, drying then swabbing with alcohol wipes Meticulous hand-washing Use of elbow-operated liquid soap dispensers rather than bars of soap Use of single-use nail brushes Use of disposable paper towels Use of hypochlorite disinfectant solutions to clean up spillages of body fluids, according to the manufacturer’s instructions
Promoting host resistance	Preoperative preparation of the patient’s skin with chlorhexidine (0.5% chlorhexidine gluconate in 70% IMS) or povidone-iodine (10% povidone-iodine in water or IMS, releasing 1% active iodine), left in situ for 5 minutes Postoperative skin dressing of chlorhexidine or povidone-iodine Use of antimicrobial agents, such as silver, iodine, antibiotic or antifungal agents when frank infection is noted or suspected Advice to diabetic and immunocompromised patients on general care and health