Lab 3b: Types of Resistance Training

What are three types of muscle contractions?

1. Isometric

2. Isotonic

3. Isokinetic

Define an isometric contraction.

Contraction where the angle stays the same

Define an isotonic contraction.

Contraction with the same load

(concentric, eccentric, concentric - eccentric)

Define an isokinetic contraction.

Contraction with the same speed

Is there a difference between concentric and eccentric training for strength and performance gains?

There is no difference in strength or performance gains between concentric and eccentric training

However, combined training of each is superior to training just one alone (in LE muscles)

“When a load is lowered, the forces exerted by the load are controlled, not by the _______ components of muscle, but also by the _______ components of the muscle”

“When a load is lowered, the forces exerted by the load are controlled, not by the active contractile components of muscle, but also by the non-contractile components of the muscle”

Force sharing in ____ (eccentric) may occur if the length is really long

Force sharing in PEC (eccentric) may occur if the length is really long

What protein contributed to reducing compliance and adding tension?

Titan

What component(s) share the load with muscle?

SEC components will share the load with muscle

If the load is constant, _______ tension is generated during the _________ phase

If the load is constant, less tension is generated during the eccentric phase

How is EMG different when considering concentric and eccentric training?

EMG activity is less

The relative load (force/area) will be _______ in eccentric because of ______ fibers being active.

The relative load (force/area) will be greater in eccentric because of fewer fibers.

Fewer fibers are active and have a greater force per fiber

Considering eccentric and concentric training, how can DOMS be minimized?

If you do eccentric training with max concentric load

What type of muscle contraction produces the greatest amount of muscle activity?

Isometric contraction

What are the advantages of an isometric contraction?

Allows for early strengthening when ROM is limited

Also helps with biofeedback of muscle contraction

What are the disadvantages of an isometric contraction?

• Only strengthen ± 10 degrees of ROM

• Training at longer muscle length may have more carryover to other angles

• Greater number of reps of isometric increases the carryover to other angles

How should we dose isometric contraction (to increase strength)?

• Contract for 3 - 10 seconds

• 3-40 contractions per day

• 3-7 days per week

With isokinetics, the force applied by the muscle is dependent on…

Dependent on the force applied on the equipment

(speed of motion is controlled)

What are the advantages of isokinetics?

• Able to train at high and low speeds in a single joint manner

• Provides a constant resistance throughout movement

• Good for testing

• Can be used for numerous settings

• Can perform eccentric actions at various speeds

What are the disadvantages of isokinetics?

• Very expensive

• Increase time for set-up

• May not be functional

• Eccentric action is essentially an isometric contraction at various lengths rather than physiological eccentric activity

What is occurring during open-kinetic chain movements?

• Increased acceleration (tensile) forces

• Increases distraction and rotational forces

• Increased deformation of joint and muscle mechanoreceptors

• Concentric acceleration and eccentric deceleration forces

• Can be used effectively with individuals that need to improve strength, neuromuscular control, or endurance of isolated muscle groups

What is occurring during close-kinetic chain movements?

• Increased joint compressive forces

• Increased joint congruency

• Decreased shear forces

• Decreased acceleration forces

• Large resistance forces

• Stimulation of proprioceptors

• Enhanced dynamic stability

• Very functional for lower extremity and is a good way to improve the strength and control of the “girdle” muscles

How does the external moment arm differ in free-weights vs. machine weights?

Free Weights: the external moment arm changes throughout the lift

Machine Weights: the external moment arm is designed to match the internal moment arm

When considering stability, how does it differ in free-weights vs machine weights?

Free Weights: requires stability

Machine Weights: provides external stability

How many planes of motion can you move in when using free weights?

Can perform movements in multiple planes

How many planes of motion can you move in when using machine weights?

Can perform movements of a single joint and single plane movement

Are free weights or machine weights better at isolating a single muscle group?

Machine weights

T/F: Both free weights and machine weights are limited in weight increments

True

Are free weights or machine weights better to be used with functional movements?

Free weights

What are some advantages to using resistance bands?

• Easily accessible

• Inexpensive

• Can be used with increasing speed

What are some disadvantages to using resistance bands?

• Lack of stabilization

• Latex might be an issue

• Resistance (might not provide enough resistance for some individuals to fatigue them quickly)

What is circuit training?

Training large muscle groups (10-12) in a pre-established sequences that will address an entire body workout

Alternate upper body, lower body, and reciprocal muscle groups

For circuit training what reps, intensity, and rest time is typically used?

• 8-12 reps

• 70-90% of 10 RM

• 15 seconds rest between sets and stations

T/F: In circuit training, exercise order is not important

False!

Exercise order is important to avoid fatigue

What is plyometrics?

• Combines speed of movement and strength

• Involves quick, powerful movement

• Involves pre-stretching of the muscle and activating the stretch-shortening cycle to produce a stronger contraction

• Very functional because training in a biomechanically accurate manner

Plyometrics heightens the ________ system

Plyometrics heightens the nervous system

What two components does plyometrics take advantage of?

• Stretch-shortening cycle (PEC and SEC)

• Alpha-Gamma co-activation

What is an important consideration before having a patient perform plyometrics?

You have to make sure that the client is able to tolerate the activity

What is the goal of plyometrics?

Want to have a short amortization phase/period (amortization is the time between a concentric and eccentric contraction)

What three components must a client have for a plyometric program?

• Client must have adequate strength (should thus be strengthened in a functional matter)

• Must be stable (static and dynamic)

• Must be flexible (both static and dynamic)

What would be a typical substitution pattern for someone that has a weak deltoid or supraspinatus?

Elevation of scapula and ER to use biceps to elevate

What would be a typical substitution pattern for someone that has a weak gluteus medius?

Contralateral trunk lean (CKC) or in OKC will hip hike

What would be a typical substitution pattern for someone that has a weak biceps brachii?

Shoulder extension, scapular retraction, and maybe some backwards trunk lean

What would be a typical substitution pattern for someone that has a weak quadriceps (CKC)?

Forward trunk lean, active hip extension and ankle plantarflexion

What are the five main questions that we need to consider to guide treatment selection?

• What is affecting muscular performance?

• What type of resistance would be most appropriate?

• What are the goals of resistance training?

• Are there any restrictions?

• What equipment is needed?

What factors do we need to consider for general progression?

• Intensity (load)

• Body position (non-WB or WB)

• Reps and sets

• Frequency

• Type of contraction

• ROM

• Plane of movement

• Velocity

• Neuromuscular control

• Functional movement pattern