1. Strength Training

Strength training is a process in which a series of progressive exercise or work is used to attain strength, speed and endurance

Work is defined as applying a force to an object and moving the object through a distance. greater strength or the ability to generate greater forces, will allow for more work to be done.

Further, if a muscle or muscle group is stronger and capable of generating greater forces, it does not have to work as hard to perform submaximal levels of work.

As the muscle group is not strained to perform the task, it has a greater tolerance to performing work, and risk of injury is reduced.

Physiological changes in strength training

Strength training produces a number of physiological changes in the muscle tissue

The major categories of tissue change that occur are :

1. aerobic changes
2. anaerobic changes
3. slow and fast twitch muscle fiber changes

Aerobic Changes

• Increased myoglobin content which aids in the delivery of oxygen from the cell membrane to the mitochondria
• Increased oxidation of carbohydrates which increases the muscle capacity to generate energy
• Increased size and number of mitochondria along with higher concentration of enzymes that are involved in the kreb’s cycle. thus, the muscle can strore more glycogen
• Increased oxidation of fat through submaximal endurance activities resulting in less lactic acid buildup and less fatigue

Anaerobic Changes

• There is increase in the muscle’s capacity to store adenosine triphosphate-phosphocreatine (ATP- PC) along with key enzymes that break down the PC. this system allows a fast release of energy by muscle cells for short bouts of activity

The Fast and Slow twitch muscle fibers

They increases their aerobic potential equally with aerobic training. the fast twitch fibers, however, have a greater glycolytic capacity due to the increased number of mitochondria.

These physiological changes demonstrate that the body will adapt to the specific demands imposed upon it. Physiological changes will occur with any type of training effects are specific to the type of exercise performed.

Postural Changes

Strength training involves variety of postures categorized as open chain, close chain, and sustained positions.

An open chain position is when the proximal aspect of muscle is fixed and the distal end moves through a range of motion. an example of an open chain exercise of the quadriceps would be a long arc quad.

A close chain position, conversely is, when the distal aspect of the muscle is fixed and the proximal end moves through a range of motion. An example of close chain exercise of quadriceps would be a partial squad

Sustained position are when opposing muscle groups are contracted to maintain a particular static position. for example, static standing requires the co contraction of the back extensors as well as the abdominals.

Program Goals

The goals of the strengthening exercise program would

• Improve the capability to handle or apply force to weighted objects
• improve the endurance to sustain an activity
• improve neuromuscular recruitment patterns, providing greater cocordination and agility

Assessment

typically, 20 to 30 minutes of time would be spend in strengthening activities each day. prior to designing the program and establishing the specific exercise to be performed.

An assessment of the individual’s strength and weaknesses should be performed.

The examiner can use the result of functional capacity assessment and orthopedic evaluation to identify specific muscle and muscle group weaknesses and strengths.

A program can be developed that will address these issues as they relate to the injury occured in those persons with chronic injuries, requiring an extensive strengthening program

Selection of exercise and equipment

• Isometric and active exercises are the most gentle variety, yet they still provide for strengthening
• free weights, dumbbells, and cuff weights, are beneficial not only to exercise a specific muscle, but also to strengthen the muscles stabilizing the joint being moved.
• resisted exercise machines
• Isokinetic equipment
• theraband, theratubing, and sports cords
• gymnastic balls