Muscle Performance
Variable Reistance
Cybex machines: Provides varying levels of resistance through exercise to load muscles more effectively at multiple points in ROM Elastic resistance band/tube (TB) Advantages: Cheap and inexpensive Portable Disadvantages: Objectivity depends on where and how stretched out band is Latex Need to be replaced
Functional Protocols
EMOMs AMRAPs
Oxford Regimen
10 reps at 100% 10RM 10 reps at 75% 10RM 10 reps at 50% 10RM
DeLorme Regimen
10 reps at 50% 10RM 10 reps at 75% 10RM 10 reps at 100% 10RM
DAPRE method
10 reps at 50% 6RM 6 reps at 75% 6RM Max reps at 100% 6RM Max reps at 100% adjusted working weight ↓ Based on # of reps in set 3 0-2 = decrease 5-10lb for set 4 (next session decrease 5-10lbs) 3-4 = decrease 0-5lbs for set 4 (next session same weight) 5-6 = keep same weight for set 4 (next session increase 5-10lbs) 7-10 = increase 5-10lbs for set 4 (next session increase 5-15lbs) 11+ = increase 10-15lbs for set 4 (next session increase 10-20lbs)
DeLorme Method
3 sets of 10 reps: 1st set 50% 10RM 2nd set 75% 10RM 3rd set 100% 10RM
Endurance
Ability of a muscle to contract repeatedly against a load and for an extended period of time Muscle endurance is different than cardiopulmonary or cardiorespiratory endurance
Strength
Ability of a muscle to produce force Greatest measurable force that is exerted by a muscle or group during a single max effort (AKA 1 rep max)
Force
Ability of the contractile (muscle) and noncontractile structures (tendons) to produce movement and provide dynamic stability around joints during static and dynamic tasks
Taxonomy of motor tasks: Manipulation of objects
Absent: UE's are not doing anything Less complex Present: UE's required to manipulate an object More complex Ex: throwing/catching object while in SLS, holding a child during sit to stand, holding arm's out straight or in a certain position
Manual Resistance
Advantages: No equipment Do it at home PT will have close monitoring (can feel how much strength through range) Touch can have healing properties Disadvantages: If person providing resistance is weaker (generally you will fatigue before them) Varies PT to PT (less objective) Hard to quantify Cannot do it by themselves
Progressive resistance exercise
An intervention used to address impaired muscle performance by increasing muscle force production Principles: Perform repetitions until fatigue Allow sufficient rest between exercises until recovery Increase the resistance as the ability to generate force increases
Exercise order
Appropriate order Big muscle groups then go down to smaller more isolated things Address most important thing in first then do more functional things
AMRAPs
As many reps as possible Fixed total WORK time: 5,15,20,30 min etc Complete all reps for 1 exercise before moving to the next Number of exercises varies (usually 3-5) 15 minute AMRAP: 2 burpees 5 chair dips 8 deadlift pull 10m farmers carry
Questions to ask when choosing type of exercise
Based on exam, what are type and extent of impairments? Based on pathology or stage of healing, what type of resistance is most appropriate? What are the goals/functional outcomes? Will dynamic or static strength be more effective for outcomes? What are the restrictions or limitations to positioning? What is WB status? Is there a portion of ROM that cannot be controlled safely? How will patient perform exercise at home? What types of equipment is available? What types of exercise replicates functional activities of the patient?
Taxonomy of motor tasks: Desired outcome
Body stable: Body is stationary Ex: Maintaining balance while standing on 1 leg; drinking a glass of tea in the kitchen Body transport: Body is moving from 1 place to another Ex: transfers, climbing, squatting, lunging, walking, ascending/descending stairs
How to measure intensity
Borg scale Exertion scale RPE scale We can tell how hard they are working: Facial expression SOB Change in vital signs Trembling Form breakdown Sweating Failure to continue
Factors that affect force production
CSA and size of the muscle (the larger the more force production potential) Fiber arrangement and length (short fibers, pennate/multipennate design typically found in high-force production muscles) Fiber-type distribution (type IIA or IIB favor rapid high force; type 1 fibers favor low force production) Length-tension relationship (muscles produce greatest tension near/at resting length) Moment arm (longer is better) Recruitment of motor units (greater number and synchronization = greater force production) Rate of MU firing (higher firing frequency = greater tension) Type of muscle contraction (eccentric > isometric > concentric) Speed of contraction (CONC = increase speed, decrease tension; ECC = increase speed, increase tension)
Reversibility Principle
Changes in muscle performance due to PRE are transient Use it or lose it Detraining begin 1-2 weeks after stopping PRE
Taxonomy of motor tasks: Environmental conditions
Closed: Stationary Objects around pt and surface on which task is performed do not move Ex: standing in an empty room, eating while sitting in a chair, tall kneeling on the mat Open: Objects or people in environment are in motion or support surface is unstable Ex: Maintaining sitting balance on a moving surface Standing on a moving train Crossing a street at a busy intersection
DOMS
Delayed onset muscle soreness Soreness, tenderness, aching: Develops 12-24 hrs after exercise, peaks 48-72 hrs and subsides 2-3 days later Soreness/pain with passive lengthening or active contraction Local edema and warmth may be present Decreased ROM during time course of soreness Decreased strength prior to onset of soreness and may persist 1-2 weeks after soreness subsides Cannot completely prevent (but can make better): Warm up, and cool down Just help them feel better (no treatment)
How to know how much to use (what percent of RM) for training
Depends on different literature (Look at slide 16 of management of impaired muscle performance)
Submaximal vs maximal loads
Depends on: Goals Expected functional outcomes Cause and extent of muscle performance deficits Stage of healing of injured tissues Age General health status Fitness level Psychological readiness/status General indications for low intensity: Sedentary Comorbidities (related to energy system) Post-op phase (relative health status) Medications Warm up and cool down vs actual exercise Initial evaluation General indications for high-intensities: Return to sport (high demand activities) Previous fitness level Healthy adults Shorter timeframe (is it safe) What are we training for
Closed kinetic chain
Distal end is fixed Interdependent joint movements Utilize multiple muscle groups Emphasize joint compression (axial loading), performed in WB More co-activation, dynamic stabilization, proprioception, NM control
Open kinetic chain
Distal end is free to move Independent joint movement Muscle activation predominatly in prime mover (isolated) Typically performed in NWB Focus on motion at single joint (can isolate joint or muscle)
Progressive resistance exercise (PRE)
Do a small number of reps until fatigue Rest, then repeat Progress
Benefits of resistance exercise
Enhanced muscle performance through restoration, improvement or maintenance of muscle strength, power, and endurance Increased strength of connective tissues: tendons, ligaments, and intramuscular connective tissue Increased bone mineral density and/or less bone demineralization Decreased joint stress during physical activity Reduced risk of soft tissue injury during physical activity Improved capacity for repair and healing of damaged soft tissues and for tissue remodeling Improve balance Enhanced physical performance during daily living, occupational, and recreational activities Positive changes in body composition: increase lean muscle mass or decrease body fat Enhanced feeling of physical well-being Positive perception of disability and QOL
EMOMs
Every minute on the minute Perform 1 exercise per minute: Work for TIME (30 sec on, 30 sec off) Work for REPS (10 overhead presses, remaining time = rest) Can add 1-3 minutes of rest Circuit training with different movements (reps examples): 10 pushups 10 air squats 10 item pickups Rest and then repeat 3x (12 min) Easy to be objective and show progress)
Progressive overload components
FITTVP Frequency Intensity Time Type Volume Progression
Constant Resistance
Free weights, handheld cuff weights, weight machines, pulley systems Advantages: Use weights at home Objective Consistent (from documentation) Fucntional Single or multiplane Can adjust speed Disadvantages: Might not have weights at home (and when getting stronger will have to continuously get new weights) Torque through ROM changes (muscle is only challenged maximally at one point)
Dynamic Exercise: CONC/ECC
Greater loads can be controlled with ECC Gains in strength/mass greater with max effort ECC training Adaptations associated with ECC training are more mode and velocity specific ECC contractions more efficient metabolically, less fatigue Greater chance and more severe DOMS with ECC: Especially with rapidly progressed high intensity training Greater stress on CV system during ECC because greater loads can be used CONC/ECC are important because both done in real life
Duration
How long pt is going to do progressive resistance exercise: Weeks to lifetime (low long is pt really gonna do it) Need at least 6-12 weeks for significant changes
Overload principle
If you want to improve muscle performance, the resistance load placed on our bodies must continually be increased as our bodies adapt to the current load To continually challenge muscle = manipulate the intensity of exercise or volume
Specific Adaptation to Imposed Demand (SAID) Principle
If you want to improve strength, you must use a resistance and dosage that will improve strength. To train endurance = use a resistance level and dosage that will address endurance To train power = use a resistance and dosage that will improve power Have to consider: The pts function Mode and velocity of exercise Position of exercise Movement patterns used This principle is about SPECIFICITY
Taxonomy of motor tasks example
Look at slide 50 of management of impaired muscle performance
Periodization
Made for high developed athletes Approach that partitions a training program into specific time intervals and establishes systemic variation in intensity, reps, sets, frequency Goals: Prepare for a peak performance Optimally progress a training program Prevent overtraining and psychological staleness
Dynamic exercise: Type of resistance
Manual resistance Constant resistance Variable resistance
Muscle performance
Muscle's capacity to do work
Physiological adaptations to resistance training
Neural system Skeletal muscle structure Body composition Hypertrophy Plasticity Connective tissue
Frequency
Number of resistance training sessions/week: Depends on intensity and volume (biggest factor - Low intensity high volume = more & high intensity low volume = less times/week) Depends on goals, stage of healing, post-op phase, general health status, previous participation, response to training, intensity, volume Optimal frequency: To gain = min 2-3x/week (may start with daily or multiple times/day) To maintain = 1-2x/week
Physiological adaptations to resistance training: Hypertrophy
Occurs after ~4-8 weeks of moderate to high intensity training Early as 2-3 weeks with very high-intensity training (For pts usually 6-12 weeks because we are not doing high intensity training) Greatest increase in hypertrophy associated with high-volume, moderate resistance ECC exercise
What type of kinetic chain movement increase muscle quicker than the other
Open and closed change are equal
Heavy Isometrics
Reduces tendon pain immediately Reduces excess muscle inhibition Increases muscle force Can be done anytime
Is PRE safe
Safe and efficacious intervention for many pts with muscle force deficits contributing to their motor disability: Muscle soreness is common No increase in hypertonia or stiffness in those with NM disorders No subsequent fractures in those with recent surgical fixation Should be more concerned about underdosing
Resistance exercise contraindications
Severe pain Inflammatory neuromuscular disease (don't want to make person worse by breaking down muscle) Severe cardiopulmonary disease
Rest
Shorter rest after low intensity Longer rest after high intensity
3 basic elements of muscle production
Strength Endurance Power
How do you determine 1RM
Test it Do not do 1RM as much due to safety hazard Calculate it: 1RM = (reps/30 + 1) X amount of weight used Ex. pt performed overhead press at 30lbs for 6 reps 1RM = (6/30 + 1) X 30 = 36lbs
Progression
Think about patient's goals Think logically about function • Think type of muscle contraction Think plane of movement • Think base of support Think speed or velocity Think about ROM or position Think EO or EC AND so, so, so much more!
Time
Time under tension (TUT) = total amount of time muscle activated during set ECC, pause, CONC, pause (each set 30-60sec) Exercise velocity: Force-velocity relationship Velocity-specific training Concentric = as force goes up, velocity goes down Eccentric = as force goes up, velocity goes up
Volume
Total volume = reps x sets x intensity? Inverse relationship between volume and intensity Unit-less: Ex. 3x10 at 50lbs = 3x10x50 = 1500 Depends on goal: Strength = more sets & less reps & higher weight & higher rest Power = 3-5 sets & low reps & high weight & high rest Hypertrophy = 3-6 sets & high reps & medium weight & medium rest Endurance = low sets & high reps & low weight & low rest
Transfer of training
Training effects have been shown to crossover or transfer form one variation of exercise or task to another Ex. carryover effect with respect to velocity of training, type or mode of exercise, and from limb to limb Muscle strengthening program can moderately improve muscular endurance (but not vice versa)
Physiological adaptations to resistance training Plasticity of type IIB fibers
Transformation of IIB to IIA with endurance and heavy resistance training (early phase) which makes them more fatigue-resistant
Mode
Types of exercise)
Resistance exercise precautions
Valsalva maneuver (or breath holding) Substitute motions Overtraining and overwork Exercise induced muscle soreness: Acute muscle soreness Delayed onset muscle soreness Pathological fracture Medications
Alignment and stabilization
What position are you putting them in How the muscle is working Form (control)
Power
Work produced by a muscle per unit of time (force x distance/time) Related to strength and the speed of performance
Taxonomy of motor tasks
system of analyzing functional activities and a framework for understanding the conditions under which simple to complex motor tasks can be performed
Taxonomy of motor tasks: Inter-trial variability
Absent: Environment is constant or unchanging Environmental conditions are predictable Little attention to task required Ex: practicing lifting with same weight; sit to stand from same chair height Present: Environment is changing or variable Requires more attention to task Ex: Lifting objects of different size and weight; climbing stairs of different height
Determinants of resistance exercise program
Alignment Stabilization Intensity Volume Exercise order Frequency Rest interval Duration Mode Velocity Periodization Integration
Age-related changed in muscle performance throughout lifespan
Early childhood and preadolescence: Muscle strength and endurance increase linearly throughout childhood until puberty ~10% greater in males than females Strength training gains occur equally in males and females (neuromuscular adaption) until puberty Resistance training can benefit children (not sure exactly when/how programs should be structured) Adolescence: Rapid increases in muscle fiber size and muscle mass Rapid increase in muscle strength for males and females Big difference in overall strength between sexes Strength training is beneficial for this age group Relative strength gains are similar between sexes (boys experience greater muscle hypertrophy) Young and middle adulthood: Muscle MASS peaks in women 16-20 Muscle MASS peaks in men 18-25 Muscle STRENGTH peaks in women 10-19 Muscle STRENGTH peaks in men 20-29 Start losing muscle mass around 25 For active individuals, strength declines start a later age and occur less rapidly Good potential for strength gains in this age group with resistance training Late adulthood: Decline in muscle STRENGTH and muscle MASS really picks up Muscle fiber CSA, type 1 and type 2 fiber quantity, number of alpha motoneurons, muscle contraction speed, and peak power production decrease In 50s, ability to perform functional skills starts to decline (significant in 60s) Resistance training programs still work in this phase of life BASICALLY: As we age everybody will experience a decline in muscle mass and strength, but resistance training programs can be safe and effective at all stages of life
Factors outside of muscle and nerve properties that affect muscle force production
Fatigue: Muscle (local) fatigue = gradual decline in muscle force production in response when a muscle repeatedly contracts (affected by fiber-type and distribution, type IIb fibers fatigue relatively quickly while type 1 are more resistant to fatigue) Cardiopulmonary (central) fatigue = systemic diminished response to a stimulus as a result of prolonged physical activity (influenced by overall health status, lifestyle, and diet) Psychological and cognitive factors: Fear of pain/injury/reinjury, depression, attention, memory, motivation, and general outlook can also influence muscle force production Age and Gender: Muscle performance potential changes across lifespan
Intensity
How much weight/resistance The load: Submax vs max (rarely do max) Where to start = based on assessment Where do we train Use of repetition max: Help us start somewhere = more objective & not as many tools) 1RM vs 6RM vs 10RM Objective measure for baseline and goals
Type
Manual/mechanical resistance Isometric exercise Dynamic exercise: CONC/ECC Constant or variable resistance Isokinetic Open chain vs Closed chain
Isometric exercise
Minimize muscle atrophy if joint movement is restricted: Ex. post-op, cast, splint, etc Loss of static muscle strength with immobilization is estimated to be 8%/WEEK to 5%/DAY Re-establish NM control when joint movement is not advisable Develop postural or joint stability Used when dynamic resistance could compromise joint integrity 20x6 sec at near-max resistance shown to improve isometric strength Muscle setting = decrease pain/spasm, promote circulation, slow atrophy, maintain mobility
Physiological adaptations to resistance training: Skeletal muscle structure
Strength training adaptations: Hypertrophy (greatest in type IIB fibers) Possible hyperplasia of muscle fibers (if they get too big they become inefficient so they split) Fiber type composition: remodeling of type IIB to IIA, no change in type I to II Decrease or no change in capillary bed density Decrease in mitochondrial density and volume (increase in muscle synthesis and decrease in breakdown) Endurance training: Min to no fiber hypertrophy Increase in capillary bed density Increase mitochondrial density and volume
Physiological adaptations to resistance training: Body compostition
Strength training adaptations: Increase lean (fat-free) body mass Decrease body fat percentage Endurance training adaptations: No change in lean body mass Decreased body fat percentage
Physiological adaptations to resistance training: Neural system
Strength training adaptations: Increase recruitment in number of motor units Increase rate of firing (decrease twitch contraction time) Increase synchronization of firing Endurance training adaptations: No changes In 1st 4-8 weeks of resistance training, EMG activity increases with little to no evidence of muscle hypertrophy Neural response attributed to motor learning and improved coordination: Decreased inhibition of CNS, decreased sensitivity of GTO, or changes at myoneural junction of MU
Physiological adaptations to resistance training: Connective tissue
Strength training adaptations: Increase tensile strength of tendons, ligaments, connective tissue Increase bone mineral density No change or increase bone mass Endurance training adaptations: Increase tensile strength of tendons, ligaments, connective tissue Increase bone mineralization with land-based WB activities Increased tendon/ligament strength/thickness occurs to support adaptive strength and size changes of muscle Non-contractile tissue strength may develop more rapidly with ECC exercise
