ortho science Flashcards
exercise science
Isotonic
Isometric
Concentric
Eccentric
Isokinetic
Pylometric
Open Chain
Closed Chain
isotonic
isometric
isotonic: **force remains constant **through ROM (constant muscle tension as muscle changes length)
Isometric: constrant muscle length and tension that is proportional to external load. Causes muscle hypertrophy.
(skeletal muscle length-tension relationship for voluntary force generation)
isotonic: bicep curls, free weights
isometric: pushing against immovable object.Isometric contractions are those in which muscle length remains constant during force generation. They illustrate the length-tension relationship, which states that force generation is wholly dependant on the length of the muscle while contracting. If the length is too long, the sarcomeres generate little or no active tension. If a muscle is overstretched, which may occur during certain surgical procedures, then the patient may generate less than 30% maximal force. Muscle force during isometric contractions (muscle not allowed to shorten) varies with starting length. If the length is too long, the sarcomeres generate little or no active tension.
concentric
eccentric
Two types of isotonic contraction:
Concentric: Shortened muscle and tension that is proportional to the external load. Bicep curl w/ elbow flexing
eccentric: force remains constant as muscle lengthens. Most efficient method of strengthening muscle. Bicep curls with elbow extending
isokinetic:
Plyometric:
Open Chain:
Closed Chain:
Isometric: muscle contracts at constant velocity through varied resistance. Used to objectively eval muscle strength during rehab. (Cybex machine)
Polymetric: rapid eccentric-concentric shortening. Good training for sports that require power. Box jumps
Open chain: distal extremity move freely. Seated leg extensions/curls. (where the end of the kinetic chain (the foot in this example) is moving freely and not fixed to the floor or a wall)
Closed chain: distal end of extremity is fixed. squats with planted foot
closed chain rehabilitation is emphasized in the early stages of ACL reconstruction rehabilitation because it allows physiologic co-contraction of the musculature around the knee. This is believed to decreases shear forces across the ACL reconstruction, whereas open-chain exercise can increase the shear stresses. The article by Miller and Croce, however tested 12 individuals using Cybex machines and found that there was actually greater hamstring muscle coactivation on EMG when performing isokinetic movements compared to closed-chain exercises.
closed chain exercises in shoulder rehab
closed kinetic chain exercises in the shoulder is that they allow for co-contraction of the periscapular and rotator cuff muscles.
Closed kinetic chain exercises are used early in the rehabilitation process. The distal segment is fixed, and an axial load is applied which provides glenohumeral compression and thereby reduces the demand on the rotator cuff. These exercises stimulate co-contractions of the scapular and rotator cuff muscles, load scapular stabilizers, and facilitate active motion.
Anaerobic vs Aerobic
Aanerobic
Glycolitic
Aerobic:
Energy source?
Muscle type?
Exercise Duration?
Aanerobic: ATP-CP. Type II (A,B) muscle fast twitch, 10 secs
Glycolitic: Lactic Acid,** 2-3 minutes,** low ATP yield, lactic acidosis
Aerobic: Oxidative Phosphorylation (krebs cycle), glycogen early & fatty acids after 90. Type I slow twitch, endurance, High yield ATP, requires O2, “slow red ox muscle” first to be recruited
Type IIA: aerobic and anaerobic
Type IIB: primarily anaerobic, last to be recruited
type I vs II muscle fibers
- Type I: slow oxidative, 1st to be activated.recruited, smaller contract slowly, less force, fatigue resistant.
- Type IIA: intermediate. Fast oxidative-glycolytic (type IIA)
*Type IIB: fast glycolytic (type IIB). units are the fastest and most powerful but also the most fatigue-prone.
work-out
Periodization refers to
Periodization refers to a planned variation in intensity and duration of a specific workout over a predefined duration of time.
AAOS consensus statement report periodization is superior to training techniques in which intensity and duration of training are kept constant over a given period of time. They describe specific periodization programs and also review other aspects such as sport specific training and progressive overload.
What is the most important muscle adaptation resulting from endurance training?
**increase in capillary density. ** improves blood and nutrient delivery and elimination of metabolic waste.
Increased recruitment of motor units, hyperplasia, and hypertrophy are all adaptations that occur with resistance training or strength training.
endurance (aerobic) vs strength training
Endurance: increased capillary densisty, increases in mitochondrial size, number, density, oxidative capacity increase in Type I &II and % of IIA fibers increases
Strength training: increased cross-sectional area due to hypertropjy, (hyperplasia: increased numbner of fibers less likely)
Adolescent strength training: gains in strength largely due to improved neuromuscular activation and coordination rather than muscle hypertrophy
Weight training:
Effects on muscles
increased ?
Adult strength gains are associated with?
Adolescent strength gains occur more from?
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
- increasing carb storers 3 days prior event and decreasing workout activity
- increases stores of muscle glycogen for improved edurance in events lasting longer than 90 minutes
- best technique for athlete is to instead maintain normal diet
Carbohydrate loading is the practice of maximizing glycogen stores by decreasing training and increasing carbohydrate intake the week before an endurance event. Nonendurance athletes do not benefit from this because glycogen depletion is not the limiting factor during a normal competition. Potential side effects of carbohydrate loading are water retention, muscle stiffness, and weight gain.
nutritional training
fluid loading and replacement:
magnitude of core temperature and heart rate increase accompanying work are ??
Best technique is to ??
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 replaceme enough water to maintain prepractice weight
exercise nutrition
Fluid carbohydrate and electrolyte replacement:
best down with ?? fluids of carbs and electrolytes which ??
best done with ** low osmolarity (< 10%) fluids** of carbohydrates and electrolytes which **enhances absorption in the gut **
Muscle laceration/injury: what is the ideal time for immobilization?
For muscle injuries, including partial lacerations, current literature suggests the affected extremity should be immobilized no more than 3-5 days, followed by a progressive strengthening and stretching program.
Healing a muscle injury involves two competing processes: regeneration of muscle fibers and formation of granulation tissue. Starting motion too soon after injury may increase the area of fibrous scar, and limit the ability of new muscle fibers to penetrate this area. Prolonged immobilization limits scar production but penetrating muscle fibers will lack appropriate orientation, and the muscle as whole begins to atrophy. Three to 5 days of immobilization has been shown to limit scar tissue production while the early motion helps generate appropriately organized muscle fibers and maintain strength and range of motion.
cytokine shown to promote scar tissue formation in lacerated skeletal muscle?
TGF-beta stimulates differentiation and proliferation of myofibroblast.
Muscle laceration(complete tear) fragments heal by dense connective scar tissue, mediated by myofibroblasts. TGFBeta stimulates differentiation and proliferation of myofibroblasts
Once laceration of skeletal muscle has occurred, regeneration and reinnervation is unpredictable. Regeneration may occur within 7-10 days after injury. This process is facilitated by the cytokines: IGF-1, FGF, and NGF. At the same time fibrous scar tissue forms to bridge the lacerated muscle segments. This process is mediated by TGF-Beta, which stimulates the differentiation and proliferation of myofibroblasts
