Therapeutic Interventions Week 3 - Resistance Training

Foundations of Resistance Training

• Resistance training relies on phosphagen, fast glycolysis, and oxidative energy systems, depending on the duration and intensity of the activity.

Energy Systems

• Phosphagen System:
  • Used during extremely high-intensity activities lasting 0-6 seconds, like a maximum height box jump.
  • Requires significant rest periods.
• Phosphagen and Fast Glycolysis:
  • Powers very high-intensity activities lasting 6-30 seconds.
  • Contributes to lactic acid build-up.
• Fast Glycolysis:
  • Dominates during high-intensity activities lasting 30 seconds to 2 minutes.
• Fast Glycolysis and Oxidative System:
  • Fuels moderate-intensity activities lasting 2-3 minutes.
• Oxidative System:
  • Main energy source for low-intensity activities lasting longer than 3 minutes.

Mechanics of Resistance Training

• External Torque (Resistance Torque):
  • Represents the resistance the muscle works against, like gravity on a weight during a bicep curl.
  • Affected by the mass of the body segment, added weights, and the length of the lever arm.
  • Can be modified by changing the weight or the distance of the weight from the joint.
• Factors Influencing External Torques:
  • Gravity (free weights).
  • Mass of the body segment.
  • Added mass (weights).
  • Length of the lever arm.
• Types of Exercise Equipment:
  • Cable machines.
  • Resistance bands (force increases with stretch).
  • Manual resistance.
  • Free weights.
• Internal Torques:
  • Influenced by the lever arm, point and angle of muscle insertion, force production (length-tension relations, muscle cross-sectional area, pennation), and contraction velocity.
• Joint Angular Velocity:
  • Concentric: Muscle shortening.
  • Isometric:
    • Muscle setting.
    • Multi-angle isometrics (increase strength in +/- 10 degrees, pain reduction, early-stage rehab).
  • Eccentric: Greater muscle damage and tendon strength, used in tendinopathy rehab.

Resistance Exercise Dosing

• The goal is tissue loading for healing, managing pain/swelling, increasing muscle function, ROM/flexibility, balance, coordination, agility, and improving functional movement.
• Exercise prescription should always consider the "WHY" behind the exercise.

Concepts of Muscle Performance

• Strength: The force or torque a muscle can produce (heavy lifting, high load).
• Power: Force with a time component (how quickly force is produced).
• Hypertrophy: Physiological improvement in muscle size by increasing the number or size of myofibrils.
• Muscular Endurance: The ability of a muscle to exert force over time.

Exercise Prescription and Goals

• Strength: 2-6 rep range.
• Hypertrophy: 7-12 rep range.
• Muscular Endurance: 12+ reps.
• Estimating 1 Rep Max (RM):
  • 15 reps: 65% of 1RM.
  • 10 reps: 75% of 1RM.
  • 5 reps: 87% of 1RM.
  • 2 reps: 95% of 1RM.
• Clinical Estimation of Resistance:
  • Adjust resistance to meet the goal number of repetitions.
  • Reduce load if the patient can’t meet the goal reps.
  • Increase load if the patient completes the goal reps without fatigue.
  • RPE (1-2 = easy, 3-4 = moderate, 5-6 = hard, 7-8 = very hard) can also estimate load.

Specifics of Reps, Sets, and Load Muscle Performance

• Strength:
  • Load: >85% 1RM.
  • Reps: <6.
  • Sets: 2-6.
  • Rest: 2-5 min.
• Power (Single Event):
  • Load: 80-90% 1RM.
  • Reps: 1-2.
  • Sets: 3-5.
  • Rest: 2-5 min.
• Power (Multiple Effort Event):
  • Load: 75-85% 1RM.
  • Reps: 3-5.
  • Sets: 3-6.
  • Rest: 2-5 min.
• Hypertrophy:
  • Load: 67-85% 1RM.
  • Reps: 6-12.
  • Sets: 3-6.
  • Rest: 30-90 seconds.
• Muscular Endurance:
  • Load: <67% 1RM.
  • Reps: >12.
  • Sets: 2-3.
  • Rest: <30 seconds.

Exercise Dosing for Early Rehab

• Muscle Setting and Isometrics: 10 reps of 6-second holds (1 set, 10s rest between reps) for muscle recruitment and stability.
• AROM: 30 seconds of AROM (2 sets) for active mobility and edema management.
• Early-Stage Muscle Activation: >12 reps (1-3 sets) with up to 45-50% of 1RM (RPE 2-4) to promote tissue healing. Complexity : single muscle, joint
• Motor Control: >12 reps (variable sets) with negligible load (RPE <3) for activating muscle and appropriate movement patterns. Complexity : May be single or multi-joint

Modifying and Progressing Resistance Exercise

• For new exercises or low fitness, 1 set of 8-12 reps at 45-50% 1RM is sufficient.
• Increase sets and loads as fitness progresses.
• Incorporate variation/periodization in training.
• Specificity of Training (SAID): Adaptations are specific to imposed demands (speed, load, range should match goal movement; tissue loading, movement patterns).
• Exercise Modifications to Progress/Regress:
  • Change the mode of resistance, external lever arm, and load.
  • Change the base of support (wider/narrower) and support surface (stable/unstable/compliant/firm).
  • Change the speed of movement and match the velocity to the patient’s goal.
  • Change the complexity of movement (single/multi-joint, single/multi-plane, isolation/functional, single/multi-task, open/closed environment, sport-specific).

Adaptations to Training and Clinical Relevance

• Increased bone mineral density with higher strain rate and magnitude loading.
• Tendon and ligament adaptations include increased collagen fibril number and diameter, and increased collagen cross-links.
• Cartilage loading/unloading is necessary for nutrient diffusion, and regular loading can increase thickness.
• Strength training does not adversely affect aerobic power (VO2 max, lactate threshold); no long-term adaptations to HR or BP.
• Neural Adaptations: Increased recruitment happens with fast twitch motor units, initial strength gains due to neural recruitment.
• Muscular Adaptations: Hypertrophy, increased insulin sensitivity, increased glycogen storage.

CPT Codes for Therapeutic Exercise

• Therapeutic Exercise (97110): Tailored exercises to improve strength, endurance, and mobility.
• Neuromuscular Reeducation (97112): Techniques to regain normal, controlled movement patterns (balance training, coordination, motor control activities).
• Gait Training (97116): Activities to improve walking ability, balance, and coordination.
• Therapeutic Activities (97530): Activities that improve functional performance through dynamic movements incorporating strength, balance, ROM, and endurance.

Therapeutic Exercise Flow Charts:

• Pain*
• Nociplastic: Pain education, active rest, isometric exercise.
• Nociceptive: Mid-range ROM, isometric or low load muscle activation, progressive strengthening exercise.
• Neuropathic: Progressive neural mobilizations, ROM progression mid-end range, stretching.
• Swelling*
• Joint: Mid-range PROM, muscle setting isometrics.
• Soft Tissue: Effleurage soft tissue work, muscle setting isometrics, mid-range PROM/AAROM.
• Tissue Loading for Repair:*
• Tendon: Progressive load isometric contractions, progressive eccentric contractions, progressive loading (varying speeds).
• Cartilage: PROM in pain-free range, low load isometric contractions, AROM in pain-free range, progressive loading.
• Muscle: PROM/AAROM in pain-free range, low load isometric contractions, low load isotonic contractions, progressive loading.
• Restricted ROM:*
• Joint ROM: PROM/AAROM in pain-free range, joint mobilization, end range ROM w/ high-grade mobilization.
• Muscle Length: Static stretching, active stretching, end range eccentric loading, dynamic movement through end range.
• Impaired Muscle Function:*
• Impaired Recruitment: NMES or biofeedback, muscle setting (isometrics).
• Atrophy: Hypertrophy training (6-12 reps, moderate load).
• Impaired Muscular Endurance: Muscular endurance training (>12 reps, lighter load).
• Impaired Strength/Power: Muscular strength/power training (Strength: 2-6 reps, heavy load; Power: 1-5 reps, quick movement).
• Impaired Motor Control:*
• Impaired Stability: Muscle recruitment, muscle strengthening, balance training (static, sensory manipulated, dynamic).
• Agility: Strength training, plyometric training, change of direction training, perceptual motor training.
• Coordination: Coordination exercise, perceptual motor training.
• Impaired Activity Performance:*
• Address limitations in ROM, muscle performance, or specific activity performance through gait training, endurance training, or therapeutic activities.

Examine energy systems used during resistance training, including the phosphagen, glycolytic, and oxidative systems. Delve into how exercise duration and intensity affect energy system selection.