Types of Contractions/Movements Type Definition Example Isotonic Force remains constant through range of motion -improves motor performance Biceps curls using free weights Isometric Constant muscle length and tension that is proportional to the external load -Causes muscle hypertrophy Pushing against an immovable object Concentric Shortened muscle and tension that is proportional to the external load Biceps curl with elbow flexing Eccentric Force remains constant as muscle lengthens.Most efficient method of strengthening muscle Biceps curl with elbow extending Isokinetic Muscle contracts at a constant velocity through varied resistance. -often used to objectively evaluate muscle strength during injury rehabilitation. Require special machines (e.g, Cybex). Plyometric Rapid eccentric-concentric shortening.Good training for sports that require power. Box jumps Open chain Distal end of extremity moves freely Seated leg extensions and curls Closed chain Distal end of extremity is fixed Squats with planted foot Anaerobic vs. Aerobic Anaerobic Glycolytic Aerobic Energy source ATP-CP Lactic acid Oxidative phosphorylation (Krebs cycle) Glycogen and fatty acids Muscle type Type II (A, B) muscle -fast twitching c Type I muscle -slow twitching Exercise duration 10 seconds of high intensity 2-3 minutes endurance Note -Type IIA: aerobic and anaerobic -Type IIB: primarily anaerobic, last to be recruited -low ATP yield-lactic acidosis after several minutes -high yield ATP-requires O2 -"slow red ox muscles"-first to be recruited Exercise Programs Definitions Periodization strength and conditioning term for planned variation in intensity and duration of a specific workout over a predefined duration of time Dynamic exercise improves cardiac output by increasing cardiac stroke volume Endurance (aerobic) Training results in changes in circulation and muscle metabolism contractile muscle adapts by increasing energy efficiency increases in mitochondrial size, number, and density increases in enzymes involved in Krebs cycle, fatty acid processing, and respiratory chain over time, increased use of fatty acids > glycogen over time, oxidative capacity of Type I, IIA, and IIB fibers increase percentage of more highly oxygenated IIA fibers increases Aerobic Threshold: level of effort at which anaerobic energy pathways become significant energy producer Anaerobic (lactate) Threshold: level of effort at which lactate production > lactate removal Strength Training typically high-load, low-repetition activities results in increased cross-sectional area of muscle due to muscle hypertrophy hyperplasia (increased number of fibers) less likely results in increased motor unit recruitment +/- improved synchronization of muscule activity maximal force production is proportional to muscle physiologic cross-sectional area adolescents can safely participate in appropriate strength training programs gains in strength largely due to improved neuromuscular activation and coordination rather than muscle hypertrophy gains for adolescents are reversible if training is discontinued Aquatic training Benefits decreases joint stress by lowering vertical component of the ground reaction force through buoyancy unique advantages in cardiorespiratory fitness when compared to land training less abrupt increases in heart rate increased oxygen consumption prevents secondary injuries to the lower limb Exercise Induced Laryngeal Obstruction (EILO) Commonly mistaken for exercise-induced bronchoconstriction in athletes Epidemiology gender - more common in females Mechanism - unknown Symptoms dyspnoea wheezing Differential diagnoses exercise-induced bronchoconstriction (EIB, or exercise-induced asthma) hyperventilation cardiac conditions Diagnosis negative bronchodilator reversibility test (with beta2-agonist) positive in EIB negative bronchoprovocation tests (e.g. methacholine challenge, mannitol challenge, eucapnic voluntary hyperventilation test) positive in EIB positive continuous laryngoscopy during exercise (CLE) Types (anatomic location) supraglottic level glottic level Treatment optimum treatment is being investigated Weight training Effects on muscles increased cross-sectional area increased strength increased mitochondria increased capillary density thickened connective tissue Adult strength gains are associated with muscle hypertrophy Adolescent strength gains occur more from increased muscle firing efficiency and coordination Nutritional training Carbohydrate loading involves increasing carbohydrates three days prior to an event and decreasing physical activity to build up carbohydrates stores increases the stores of muscle glycogen to provide improved endurance, especially in events lasting > 90 minutes when the bodies normal supply of glycogen runs low best technique for athlete is to instead maintain normal diet Fluid loading and replacement magnitude of core temperature and heart rate increase accompanying work are proportional to the magnitude of water debt at the onset of exercise best technique is to replace enough water to maintain prepractice weight Fluid carbohydrate and electrolyte replacement best done with low osmolarity (< 10%) fluids of carbohydrates and electrolyties which enhances absorption in the gut glucose polymers decrease osmolarity Muscle Injury Muscles soreness caused by edema and inflammation in the connective tissue leads to increased intramuscular pressure occurs primarily in Type IIB fibers worse with unaccustomed eccentric exercise often with delayed onset: Delayed-Onset Muscle Soreness (DOMS) peaks at 24-72 hours elevated CK levels seen in serum Muscles strain occurs commonly at myotendinous junction (often during eccentric contraction which produces highest forces in skeletal muscle) pathoanatomy in inflammation followed by fibrosis Muscle contusion non-penetrating blunt injury leads to hematoma and inflammation extracellular connective tissue forms within 2 days, peaks between 5-21 days healing characterized by late scar formation, variable muscle regeneration myositis ossificans (bone formation within the muscle tissue) most apparent 4 weeks post-injury Muscle laceration (complete tear) typically occur near myotendinous junction characterized by abnormal muscle countour fragments heal by dense connective scar tissue mediated by myofibroblasts TGF-beta stimulates differentiation and proliferation of myofibroblasts regeneration and renervation: unpredictable and likely incomplete Muscle Immobilization Can result in shorter muscle position and atrophy Leads to decreased ability to generate tension and increased fatigability Results in fatty infiltration Atrophy occurs faster in muscles crossing a single joint Atrophy occurs at a non-linear rate most changes occur during initial days of disuse seen at cellular level: loss of myofibrils within the fibers related to duration of immobilization Atrophy is more prominent if immobilization occurs without tension quadriceps atrophy greater than hamstrings with knee immobilization in extension Treatment Local treatments designed to assist with soft tissue recovery or rehabilitation Goals of treatment decrease inflammation increase local blood flow increase tissue compliance Modalities include cryo or heat treatments massage ultrasound electrical stimulation Iontophoresis use of an electrical current to drive charged molecules of medicine through the skin to the deep tissues medications including steroids, local anesthetics, salicylates, and non-steroidal anti-inflammatory drugs (see table below) indications - see table below contraindications susceptibility to applied currents e.g. cardiac pacemakers hypersensitivity/allergy to drug used Indication Iontophoresis Drug/Solution Hyperhydrosis Tap water, glycopyrrolate Muscle spasm Magnesium sulfate, calcium chloride Edema Hyaluronidase Adhesive conditions Iodine Inflammation Dexamethasone, hydrocortisone, prednisone, lidocaine, salicylates Calcific tendinitis Acetic acid Myositis ossificans Acetic acid Open wounds Zinc oxide, tolazoline hydrochloride
QUESTIONS 1 of 26 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.72) Which of the following cytokines has been shown to promote scar tissue formation in lacerated skeletal muscle? Review Topic QID: 4707 1 Fibroblast growth factor (FGF) 61% (2306/3761) 2 IGF-1 6% (226/3761) 3 Nerve growth factor (NGF) 0% (15/3761) 4 VEGF 4% (160/3761) 5 TGF-Beta 28% (1037/3761) ML 5 Select Answer to see Preferred Response PREFERRED RESPONSE 5 This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE13BS.12) Delayed-onset muscle soreness (DOMS) is initially evident at the muscle tendon junction and can spread throughout the entire muscle. It is primarily associated with what type of exercise? Review Topic QID: 8245 1 Concentric 15% (28/184) 2 Isometric 5% (10/184) 3 Eccentric 73% (135/184) 4 Plyometric 6% (11/184) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 3 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ12.226) Regarding muscle biology, all of the following descriptions are correct EXCEPT? Review Topic QID: 4586 1 Isotonic: constant tension as the muscle length changes 5% (285/5188) 2 Isokinetic: constant effort through a variable speed 87% (4502/5188) 3 Isometric: contraction with no change in muscle length 3% (142/5188) 4 Eccentric: muscle fibers lengthen as the muscle contracts 3% (155/5188) 5 Concentric: muscle fibers shorten as the muscle contracts 1% (66/5188) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ11.23) Which of the following remains constant during an isotonic exercise? Review Topic QID: 3446 1 Muscle tension 88% (2062/2348) 2 Muscle length 6% (145/2348) 3 Contraction velocity 3% (73/2348) 4 Muscle work 2% (52/2348) 5 Contraction acceleration 0% (10/2348) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 1 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.246) The exercises shown in Figure A are most appropriately described as which of the following? Review Topic QID: 3345 FIGURES: A 1 Isokinetic 4% (101/2528) 2 Plyometric 1% (18/2528) 3 Isometric 2% (54/2528) 4 Open chain 85% (2159/2528) 5 Closed chain 7% (187/2528) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ10.31) Iontophoresis, as commonly used in physical therapy, is a modality best defined by which of the following descriptions? Review Topic QID: 3119 1 Induction of muscle contraction facilitating metabolic byproduct removal 3% (63/1962) 2 Transcutaneous delivery of medication with electrical current 84% (1642/1962) 3 Transmission of high frequency acoustic waves to soft tissues 6% (119/1962) 4 A low level laser treatment 1% (11/1962) 5 Utilization of pulsed magnetic fields for recalcitrant muscle pain 6% (110/1962) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ10.178) A 78-year-old male with a history of chronic low back pain and bilateral knee arthritis enrolls in an aquatic exercise program after land training has become too painful for him. Each of the following are true regarding aquatic exercises EXCEPT: Review Topic QID: 3271 1 They function to minimize joint stress 2% (48/2917) 2 Secondary injuries of the lower limb joints can be prevented 1% (30/2917) 3 They are associated with lower maximal heart rates when matched against comparable land exercises 12% (360/2917) 4 Oxygen consumption is increased when compared to equivalent exercises on land 6% (169/2917) 5 The vertical component of the ground reaction forces increases compared to equivalent exercises on land 79% (2297/2917) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 5 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ07.17) ACL rehabilitation often includes exercises with the distal end of the extremity fixed in place with axial loading and co-contracture of muscle groups to help stabilize the joint. This type of exercise is more commonly referred to as: Review Topic QID: 678 1 Eccentric contraction 1% (22/2438) 2 Closed chain exercise 88% (2140/2438) 3 Open chain exercise 1% (26/2438) 4 Proprioceptive neuromuscular facilitation 1% (33/2438) 5 Isometric contraction 8% (207/2438) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (SBQ07SM.26) Which of the following best describes the use of closed chain kinetic exercises for shoulder rehabilitation? Review Topic QID: 1411 1 Closed chain exercises are not used for upper extremity rehabilitation 6% (26/449) 2 Causes compression of the glenohumeral joint increasing the demand on the rotator cuff 11% (50/449) 3 Causes distraction of the glenohumeral joint reducing the demand on the rotator cuff 7% (30/449) 4 Allows for co-contraction of the periscapular and rotator cuff muscles 73% (326/449) 5 Involves extrinsic loads such as exercise tubing or hand weights 4% (17/449) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ07.264) Which term used in rehabilitiation describes a strengthening exercise performed at a constant speed? Review Topic QID: 925 1 Open chain 0% (4/906) 2 Closed chain 0% (2/906) 3 Isotonic 2% (18/906) 4 Isometric 2% (19/906) 5 Isokinetic 95% (861/906) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ06.259) The strength and conditioning term for planned variation in intensity and duration of workouts over a predefined duration of time is? Review Topic QID: 270 1 Isokinetic modulation 5% (59/1209) 2 Periodization 79% (961/1209) 3 Static progressive exercise 4% (47/1209) 4 Progressive overload 4% (50/1209) 5 Stacking 7% (88/1209) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ05.206) What is the term used to describe a treatment modality that uses galvanic current and medication? Review Topic QID: 1092 1 Electromyography 1% (6/410) 2 Transcutaneous electrical nerve stimulations (TENS) 18% (74/410) 3 Photophoresis 0% (1/410) 4 Phonophoresis 2% (10/410) 5 Iontophoresis 78% (318/410) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ05.22) A physical therapist asks whether "open chain" exercises may be used in rehabilitation after knee surgery. This term refers to what type of exercises? Review Topic QID: 59 1 Supine heel slides 4% (19/492) 2 Seated leg press 3% (14/492) 3 Recumbent bicycle riding 3% (16/492) 4 Standing leg press 3% (14/492) 5 Seated leg extensions 87% (427/492) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ04.72) Isokinetic refers to which of the following types of training? Review Topic QID: 1177 1 Bicycling at a constant pedal velocity with varied resistance 80% (602/757) 2 Bicycling at a variable pedal velocity with constant resistance 17% (125/757) 3 Running a fixed distance with variable speeds (ie. intervals) 1% (7/757) 4 Running at variable speed to maintain a constant heart rate 2% (18/757) 5 Swimming the same distance each day at different speeds 0% (2/757) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ04.32) Dynamic exercise training can increase an athlete's cardiac output through which of the following mechanisms? Review Topic QID: 93 1 Increased stroke volume 86% (1788/2086) 2 Increased resting heart rate 2% (43/2086) 3 Increased aerobic capacity 11% (222/2086) 4 Increased blood pressure 0% (6/2086) 5 Increased red blood cell mass 1% (16/2086) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ04.55) Which of the following Figures represents the exercise type that strengthens muscle most efficiently? Review Topic QID: 1385 FIGURES: A B C D E 1 Figure A 7% (62/881) 2 Figure B 73% (645/881) 3 Figure C 3% (27/881) 4 Figure D 7% (62/881) 5 Figure E 9% (82/881) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 2
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