Muscle Performance Flashcards
What are the three components of muscle performance which define muscle behavior?
- Strength
- Power
- Endurance
the maximal force that a single muscle or muscle group produces during a single effort. The force is usually produced to overcome a resistance to movement
Strength
the work (force x distance) generated by a single muscle or muscle group divided by the time needed for work completion
Power
- muscular work produced per second
single bursts of high-intensity (ex = lifting heavy box, putting it on a shelf)
Anaerobic power
repeated bursts of low intensity activity (ex = climbing a flight of stairs)
Aerobic power
the ability of a single muscle or muscle group to repetitively produce the force required to sustain functional activity at a sufficient level over an extended period of time
Endurance
muscle tension developed without an external length change (constant-length) or movement
Icomentric contraction
- no length change contraction
- 6-10S holds, repeated 5-10 times
muscle tension developed with an external length change, muscle shortens; “constant force”
Isotonic contraction
- normal contraction
Why must the force vary in an isotonic contraction?
muscle length, angle of pull, and speed of shortening varies through the ROM of a muscle
- cannot maximally load the muscle through the entire ROM during a fixed resistance movement
muscle tension develops during muscle lengthening while controlling or decelerating movement
Eccentric
- greater force per cross-bridge
- smaller motor units needed to produce equivalent force production concentrically
muscle tension developed as it shortens at a constant speed and the muscle force is maximum at all joint angles through the full ROM – the velocity of movement is constant
Isokinetic
M. weakness, sore, tired, unable to complete reps, need inc. break; Must be achieved to increase strength, power, and endurance; achieved differently within Fixed, Variable, and Accommodating Resistance muscular training
Muscular fatigue
Occurs due to repeated and rapidly progressed, high-intensity eccentric muscle contractions (more so than with high-intensity concentric exercise)
delayed onset muscle soreness
- peaks 48 hours after training
Delayed onset muscle soreness, how should a physical therapist adjust a resistance training program if this occurs?
intensity and volume of eccentric exercise needs to be progressed gradually
use high resistances (>50% 1 RM) and a lower number of repetitions (3-15 repetitions); the exact resistance and number of repetitions depends on the client (age, pathology, strength etc.)
What will this build?
Strength
- max force produced
Use relatively high resistances (using a 3 to 6 RM), with fewer repetitions; moving or lifting the load in a specified amount of time. Some techniques involve reducing the amount of time to complete the movement at the given load; techniques involve risk of injury and are usually performed using explosive movements by competitive athletes
What does this build?
Power (anaerobic)
- speed of movement
Functional movements can be encouraged during functional training on stairs and also by performing step-ups. During this type of training the patient is encouraged to increase speeds to functional levels
What does this build?
Power (aerobic)
Use relatively lower resistances (15-25 RM); or a resistance that can be repetitively lifed or moved 15 to 25 times without a rest) and thus use a relatively higher number of repetitions (15-25 repetitions). These repetitions are done in sets with short rest period.
What does this build?
Endurance
- force over extended period of time
A single muscle or muscle group is required to overcome resistances on a regular basis that are greater than those that are usually encountered by the muscle(s)
Overload principle
- increase resistance
- increase # of reps
- increase # of sets
- decrease rest time btwn sets
system of dynamic resistance training in which a constant external load is applied to the contracting muscle by some mechanical means (usually a free weight or weight machine) and incrementally increased; RM is used as the basis for determining and progressing the resistance
Progressive resistive exercise (PRE)
PRE program characterized by a warm-up period; “heavy resistance training” or “load resisting exercise”; 3 sets of a percentage of 10 RM, starting with 10 reps at 50%, then 10 reps at 75%, then 10 reps at 100%
DeLorme
-1.5-2min rests
PRE program characterized a diminishment of weight as the muscle fatigues; “heavy resistance training” or “load resisting exercise”; 3 sets of a percentage of 10RM, starting with 10 reps at 100%, then 10 reps at 75%, then 10 reps at 50%
Oxford
- 45s rests
Explain how the daily adjustable progressive resistance exercise (DAPRE) program works.
Set 1 = 10 reps at 50% 6 RM
Set 2 = 6 reps at 75% 6 RM
Set 3 = Max possible reps at 100% RM
Set 4 = Max possible reps at 100% adjusted working weight
How does DAPRE determine weight adjustment (for 6 RM) for the 4th set and next exercise session?
# of reps in set 3: 0-2 = take away 5-10 lbs today and next session 3-4 = take away 5-10 lbs today and keep the same weight next session 5-6 = same weight today, add 5-10 lbs next session 7-10 = add 5-10 lbs today, add 5-15 lbs next session 11+ = add 10-15 lbs today, add 10-20 lbs next session
What kind of muscle contraction - exercises can is associated with the greatest risk for increasing the blood pressure?
occurs most often with high-effort isometric and dynamic muscle contractions (eccentric)
- related to valsalva maneuver; importance of breathing!
Resistance type: the m. is only as strong as it is at it’s weakest point; Most force is usually at mid-range
Fixed
Resistance type: Directly adapting to force by changing length of resistance arm; Cam-system; Resistance arm = short at weak points/ long at strong points
Variable
Where are gains seen with isometric training programs?
- 11% increase in contralateral limb
- Gains are greatest at the training angle, but are seen on either side of the angle
What is the progression of velocity spectrum training?
Bout 1: 15 Reps @ 60o /sec 15 sec rest Bout 2: 25 Reps @ 180o /sec 15 sec rest Bout 3: 35 Reps @ 270o /sec 60 sec rest Bout 4: 35 Reps @ 270o /sec 15 sec rest Bout 5: 25 Reps @ 180o /sec 15 sec rest Bout 6: 15 Reps @ 60o /sec
Where does strength increase in velocity specific training (isokinetic)?
Increases at each speed slower than the training speed
- larger increases seen in strength at specific speed or velocity of training
In velocity specific training, what is the benefit of slow speeds?
Larges strength increase (high loads)
