PT 506 Resistance Training Principles PDF

PT 506: Principles of Resistance Training and Applications 1. Review of energy systems for exercise1 2. Biomechanics of resistance training1 a. Torques involved1 i. External/ Resistance Torque: the torque generated by an external force (including gravity) that ac...

PT 506: Principles of Resistance Training and Applications 1. Review of energy systems for exercise1 2. Biomechanics of resistance training1 a. Torques involved1 i. External/ Resistance Torque: the torque generated by an external force (including gravity) that acts against the muscle/ internal torque ii. Internal/ Muscle Torque: the torque produced by the muscle force acting on the bone (to counter the external torque) b. External (Resistance) Torques (Clinical applications) i. Gravity (on an unloaded limb this acts at the center of mass)  exerts force ii. Length of level arm from joint center to application of load/force iii. Exercise equipment (additional modes of external force) 1. Cable machines 2. Resistance bands 3. Manual resistance iv. Open versus closed chain2 1. Open chain: proximal segment is fixed, distal is moving a. Independent joint motions 2. Closed chain: distal segment is fixed, proximal is moving a. Interdependent joint motions 3. See Kisner Table 6.7 for more Section 1 1  c. Internal (Muscle) Torques (factors influencing) i. Influence of tendon insertion (position and angle)  impacts lever arm ii. Muscle length tension relations iii. Active and passive insufficiency iv. Muscle cross sectional area v. Muscle fiber pennation angle vi. Contraction velocity vii. Joint angular velocity 1. Concentric (more to come on this) 2. Isometric: a. Muscle setting = low intensity isometrics2 i. Can maintain muscle function and fiber mobility but does NOT increase strength ii. Typically 10 reps of 6 second holds iii. Typically used in the acute phase of rehab b. Effective when goal is stabilization2 i. Multiple angle isometrics can increase strength through grater ROM with less joint stress than con/eccentric exercise c. Isometrics only improve muscle capacity +/- 10 degrees from angle performed at (minimal carry over)2 i. Need > 60% MVIC to promote increases in strength d. Can support strength maintenance and pain reduction in cases of tendinopathy3 i. 5x45second (2 minute recovery) contraction at 70% MVIC 3. Eccentric a. Eccentric associated with greater muscle damage, but also greater increases in tendon strength4 b. Eccentric loading (often in 1-3 sets of 15 reps) used to promote tendon structural healing in tendinopathy5 Section 1 2 3. Application to exercise prescription1 a. Reasons to prescribe exercise i. Tissue loading for optimal healing  typically low load ii. Manage pain and swelling  AROM/PROM and low load iii. Increase muscle function/ performance  progressive loading iv. Increase ROM/ Flexibility  joint mobilization/ stretching v. Improve balance/ coordination/ agility  specific neuromotor training vi. Improve functional movement  increasingly complex movement patterns b. Concepts of Muscle Performance1 (non-injured joint/ muscle) i. Strength 1. Ability to exert force ii. Power 1. Force x Velocity (therefore speed/time dependent) iii. Hypertrophy 1. Focus on building muscle mass/volume iv. Muscular endurance 1. Ability to sustain force over multiple repetitions or prolonged hold c. Exercise prescription for specific goals i. Relation of # of reps allowed (to failure) and muscular performance training Section 2 3  ii. Estimating 1 Rep Max Repetitions allowed Percent of 1 RM 15 65% 10 75% 5 87% 2 95% Determining 1 RM in clinical settings: ballpark what you think the appropriate resistance is. Have the patient/client perform as many reps as possible with that resistance  use the above table to determine 1RM2 Also as noted in the tables below RPE can be used to estimate load iii. Specifics for exercise prescription for muscle performance Training Goal Load (% 1 RM) Goal Repetitions Goal Sets Rest Interval >85% Strength RPE 6-8 (hard- 12 2–3 < 30 sec Endurance (somewhat hard) Section 2 4  iv. Exercise Prescription for early rehab Muscle Setting Early Stage Muscle AROM7 Motor Control8 and Isometrics2,7 Activation 10 (6 second hold 30 seconds of # of Reps >12 reps > 12 reps each) AROM # of Sets 1 2 1-3 Varies Up to 45-50% of Muscle setting = 1RM Negligible Load None None RPE 2-46 RPE < 3 (easy) Isometrics: Varies (easy/moderate) Rest b/t Sets 10 sec rest b/t reps > 1 min Muscle Active mobility, Activating muscle, recruitment, edema Promote tissue appropriate Purpose Maintain fiber management, healing movement mobility muscle fiber patterns Stability mobility May be single or Complexity Single muscle/joint Single Joint Single muscle/joint multi/joint Mental practice can also contribute Higher volume is May be enhanced Hold for 3 seconds to early strength needed Notes by using NMES9 at EROM gains10 Up to 5-10 minutes May be enhanced at a time by using NMES9 Section 2 5 4. Variations, modifications, and progressions on exercises a. Considerations for various levels of fitness i. For individuals new to training, low volume (single set) brings same results as high volume (multi-set). 1. Recommended 8-12 reps per set; can start with 1 set11 2. Can see strength gains with 45-50% 1RM12,13 3. Initial gains are due to neural adaptations, not structural muscle changes ii. Over time, though, need the higher volume and load to continue gains14 1. Heavier loads recruit larger motor units12 2. Periodization recommended for higher fitness levels11 b. Specificity of training2 i. Specific Adaptation to Imposed Demands (SAID) ii. Speed of movement, joint position, load, etc should best match goal activity iii. Training is also reversible (gains will be lost) within 1-2 weeks of ceasing exercise c. Overall therapeutic exercise must be at the appropriate intensity level for greatest improvements15 i. Consider stage of healing, what tissue is injured, and what the goal is ii. Goals typically address: 1. Progressive loading of injured tissue 2. Addressing overall movement patterns (either contributing to injury or as a result of injury) Section 3 6  d. Progressing an exercise i. Increase external torque 1. Change external resistance 2. Change the lever arm ii. Change the base of support (wide to narrow, stable to unstable) iii. Change the surface (stable, unstable, compliant/firm)16 iv. Change the speed of movement 1. Moderate velocity training shows greatest carry over to other velocities12 2. For functional performance, velocity trained should match velocity needed for function2 3. Progressively increase speed of movement to achieve desired goal16 v. Change the complexity of movement16 1. Single joint versus multi-joint 2. Single plane versus multi-plane 3. Isolation versus functional activity 4. Single task versus multi-task 5. Open versus closed environment 6. Sport specific activity and environment Section 3 7 5. Adaptations to training and Clinical Applications a. Neural response1,2 i. Increased recruitment of fast-twitch motor units ii. Neural adaptations precede muscle structural adaptations to exercise training 1. In other words, initial strength gains due to changes in recruitment, not muscle structure  this is where electric stimulation (NMES) can help 2. Neural response is especially important in situations where muscles are inhibited due to pain, joint swelling, surgery etc b. Muscular adaptations1 i. Muscle Fiber 1. Hypertrophy (increase in size of muscle fibers) 2. Hyperplasia (increase in # of muscle fibers) 3. Fiber Type Transitions a. Proportions of type I to type II fibers genetically determined b. Can have adaptation within fiber type (IIx to IIa) ii. Increased insulin sensitivity17 (this is great for diabetics!) iii. Energy Stores17 1. Increase glycogen storage (assuming adequate glucose intake) c. Connective tissue adaptations i. Bone 1. Increased bone mineral density (BMD) in response to mechanical forces  important for preventing and managing osteopenia/ osteoporosis 2. High load high strain rate (power) training needed to increase bone density18 3. Factors that influence bone adaptation to loading: a. Magnitude of the load (intensity) b. Rate (speed) of loading c. Direction of the forces d. Volume of loading (number of repetitions) Section 4 8  ii. Tendons, Ligaments, Fascia 1. Respond to mechanical load applied (greater load  greater strain  greater adaptation) a. This is why loading is so important in tendon rehab 2. Adaptations can occur at junctions and mid-structure iii. Cartilage 1. Cartilage requires loading and unloading to receive nutrition via diffusion form joint fluid 2. Regular moderate loading through ROM can increase cartilage thickness a. Can start with PROM in early stages of rehab d. Cardiovascular adaptations i. Acute responses 1. Cardiac output increases 2. Stroke volume increases 3. Heart rate increases 4. Oxygen uptake increases 5. Systolic blood pressure increases 6. Blood flow to active muscles increases ii. Adaptations 1. Resistance training does not lead to adaptations in resting HR or BP 2. Resistance training does not adversely affect aerobic power Section 4 9 References 1. Haff GG, Triplett NT. Essentials of Strength Training and Conditioning. 4th ed. Champaign, IL: Human Kinetics; 2016. 2. Kisner C, Colby LA, Borstad J. Therapeutic exercise: Foundations and Techniques. 7th ed. Philadelphia: FA Davis; 2018. 3. Rio E, Kidgell D, Purdam C, et al. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. Br J Sports Med. 2015;49(19):1277-1283. 4. Fernandez de las Penas C, Cleland J, Huijbregts PA. Neck and arm pain syndromes: Evidence-informed screening, diagnosis and management. Elsevier; 2011. 5. Rompe JD, Furia J, Maffulli N. Eccentric loading versus eccentric loading plus shock- wave treatment for midportion achilles tendinopathy: a randomized controlled trial. Am J Sports Med. 2009;37(3):463-470. 6. Day ML, McGuigan MR, Brice G, Foster C. Monitoring exercise intensity during resistance training using the session RPE scale. J Strength Cond Res. 2004;18(2):353- 358. 7. Deyle GD, Henderson NE, Matekel RL, Ryder MG, Garber MB, Allison SC. Effectiveness of manual physical therapy and exercise in osteoarthritis of the knee. A randomized, controlled trial. Ann Intern Med. 2000;132(3):173-181. 8. Dobkin BH. Training and exercise to drive poststroke recovery. Nat Clin Pract Neurol. 2008;4(2):76-85. 9. Cameron MH. Physical agents in rehabilitation: From research to practice. 2nd ed. St Louis, MO: Saunders; 2003. 10. Sidaway B, Trzaska AR. Can mental practice increase ankle dorsiflexor torque? Phys Ther. 2005;85(10):1053-1060. 11. American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687. 12. Kraemer WJ, Ratamess NA. Fundamentals of resistance training: progression and exercise prescription. Med Sci Sports Exerc. 2004;36(4):674-688. 13. Schoenfeld BJ, Wilson JM, Lowery RP, Krieger JW. Muscular adaptations in low- versus high-load resistance training: A meta-analysis. Eur J Sport Sci. 2016;16(1):1-10. 14. Marx JO, Ratamess NA, Nindl BC, et al. Low-volume circuit versus high-volume periodized resistance training in women. Medicine and science in sports and exercise. 2001;33(4):635-643. 15. Taylor NF, Dodd KJ, Shields N, Bruder A. Therapeutic exercise in physiotherapy practice is beneficial: a summary of systematic reviews 2002-2005. Aust J Physiother. 2007;53(1):7-16. 16. Brody LT, Hall CM. Therapeutic exercise: Moving toward function. 4th ed. Philadelphia, PA: Wolters Kluwer; 2018. 17. Perseghin G, Price TB, Petersen KF, et al. Increased glucose transport-phosphorylation and muscle glycogen synthesis after exercise training in insulin-resistant subjects. N Engl J Med. 1996;335(18):1357-1362. 18. Shipp KM. Exercise for osteoporosis: beyond weight bearing for prevention and treatment. Paper presented at: Exercise and Physical Activity in Aging; 2010; Indianapolis, IN. Section 4 10 Section 4 11