Wxercise is very important to the rehabilitation process. The more we can teach clients proper motor control, strengthening, flexibility, proprioception awareness, and balance, the better the client will succeed. As clients progress their physical demands change, so it is vital for the therapist to be aware of these demands and make the appropriate changes to achieve the most effective treatment plan for their clients.

Generally, resistance training is valued for the significant customization ability PTs have for their clients. The same exercises can be customized for individual clients for their own tolerance of intensity, repetitions, and more. Programs also can be customized by patient goals, from regaining balance to reassuming optimal athletic performance. Finally, resistance is tailored to the client. Each client, and each muscle and bodily structure, has a certain tolerance toward stress, and the PT can use resistance training to find that sweet spot—the point at which the muscle is stressed correctly in order to get stronger and grow.

Of course, the PT's focus in resistance training becomes finding that sweet spot, the optimal level of appropriate resistance for clients. PTs must find the correct amount that doesn't push clients too hard and doesn't push them too little. The means of doing this is through progression, a methodical process of movement and preparing the patient for growth. The process moves from simple muscle-isolation exercises and contractions to more complicated load-bearing activities. Resistance usually is created with simple gravity, then other manual loads.

But PTs face significant challenges finding the best way to do this. Clients need to function quickly. They need strength without sacrificing other structures besides muscles. They need something that encourages them to continue and improve. For some PTs, the advanced machines and tools available on the market today are just the solution. The use of exercise equipment has changed in the last few years. There are so many variables with what types of equipment are used. There is a greater focus on functional exercises and equipment rather than equipment used mostly for research or testing.

As PTs know well, the mechanisms of resistance training apply to all body parts, whether upper body or lower extremities. Resistance training for rehab and performance improvement is particularly helpful for athletes and sports enthusiasts.

IN THE NEWS

Much of lower-extremity resistance training is functional, recreating and strengthening the way the body executes daily physical activities. The progression of resistance training recruits multiple muscle groups at once to rebuild the simplest to the most complex, sports-performance-oriented movements.

The benefits of resistance training are not limited just to athletes for sports-specific training or rehabilitation. Recent studies show positive effects of resistance training for patients with various conditions.

One recent study showed that resistance training was successful in getting 90% of workers with severe rotator cuff injuries back to work.¹ Jamie Stark, director of research and development at the Athletic and Therapeutic Institute in Chicago, described this and five related studies of workers suffering work-related rotator cuff and lumbar fusion injuries at the Experimental Biology 2007 meeting in Washington, DC. His presentations are part of the scientific program of the American Physiological Society.

Participants in the rotator cuff study represented a class of "worse-case-scenarios" of work-related injuries. All 42 of the employees had been through surgery to repair their torn muscles or ligaments. All had already gone through weeks of traditional rehabilitation and physical therapy. Even so, none had been judged capable of going back to work and thus were eligible for disability and workers' compensation settlements.

The injured employees attended the Institute program 4 hours per day, 5 days per week, on average for 6 weeks. Their daily training began with a warm-up, stretching, and core exercises for balance and proper biomechanics, then moved to free weight resistance training of the upper and lower body.

Unlike traditional physical therapy programs after injuries, this program was a modified version of what professional and collegiate athletes do using free weights. On the third day of the week, the exercises involved less weight than the previous 2 days but were much more dynamic, addressing specific injury and biomechanical patterns related to the workers' previous jobs. A drywaller, for example, would work muscles used in lifting large sheets of drywall overhead and in place. During the last 2 days of each week, the amount of weight used during free weight lifting was heavier than that of the first 2 days of the week.

At the end of the 6 weeks' training, the workers were tested on physical function (a 4-hour protocol based on US Department of Labor classifications of different types of work). Ninety-six percent of patients met or exceeded the physical function levels of their previous job, and 90% went back to work, most at their previous job. Almost all employees were satisfied with the program, and so were employers.

Another recent study showed that resistance training can be safe and beneficial for heart disease patients.2 A report released by the American Heart Association (AHA) stated that resistance training not only enhances the benefits of aerobic fitness, but it appears to provide the added benefit of increased functional capacity and independence. It helps people better perform tasks of daily living—like lifting sacks of groceries.

In the report, the AHA writing group discusses the impact that resistance training has on the structure and function of the cardiovascular system and how it modifies known risk factors for cardiovascular disease. For clinicians, the report shows how to evaluate potential candidates for resistance training and details initial training recommendations, including:

• Perform exercises in a rhythmical manner at moderate to slow speed.
• Exhale during the exertion phase of a lift and inhale during the relaxation phase to avoid breath- holding and straining.
• Alternate between upper- and lower-body training to achieve adequate rest periods between exercises.

The statement also describes the appropriate resistance or weight load for clients initiating resistance training. For instance, the initial load should allow healthy sedentary adults to perform eight to 12 repetitions per set.

RESISTANCE TRAINING TOOLS

According to the American Sports Medicine Institute, the goal of resistance training is to gradually and progressively overload the musculoskeletal system so it gets stronger. This can be done with free weights, machines, or products such as exercise tubing.

Free weights help build coordination because it takes skill to move and control the dumbbells. For example, if clients are doing dumbbell presses, they must control the motion so that the dumbbells move straight up and not outward. If they are doing a squat, they must be able to steady themselves so that they don't fall.

Resistance-training machines are usually simple to use. Most machines simply require adjustment of weight, which can be easily changed depending on the needs of the client. One thing to keep in mind is that each machine is typically limited to working just one muscle group, so you need lots of machines to cover all the muscle groups. The exception is the cable pulley machines, which are extremely versatile, allowing clients to perform multiple exercises on one machine.

Exercise tubing consists of elastic tubes with handles that can substitute for free weights or machines to help clients build strength and tone. They come in various thicknesses to increase the tension (and are different colors to denote the tension). They have never been tested head-to-head against free weights or machines, but remember that resistance exercise is any activity that causes muscles to contract against external resistance. Tubing does just that. Exercise tubes are an inexpensive and versatile way to get started with resistance exercise.

ON THE MARKET

Here's a sampling of the various resistance-training products on the market today.

Contemporary Design Co, based in Glacier, Wash, offers the Shuttle System, which features a horizontal orientation for patients, negating the pull of gravity during exercise. The Shuttle System has opened up rehab possibilities for many clients with restricted ranges of motion through the lower extremities.

The Total Gym PowerTower, offered by EFI Sports Medicine, San Diego, focuses on function in resistance training through its incline plane design, which allows the client's body to rest at an angle. Resistance harnesses gravity and body weight to challenge patients. Exercises start at the user's ability level, and body weight resistance on the free-rolling glideboard challenges the proprioceptors, stabilizes muscle, and adds multiplane movement and unrestricted range of motion.

Med-Fit Systems, Fallbrook, Calif, offers the Nautilus leg press, which is available as a separate machine or as part of a greater multiuse system, with models including the Studio series, the Nitro series, and the 2ST series. The recumbent orientation on the Nautilus machines work to improve on sled-style and seated lower-extremity resistance training. Older machines limited quad and glut work to the poundage tolerated by the spine. New machines and the Nautilus line fully support the torso and prevent resistance loading on the spine, which can exacerbate shoulder, cervical, thoracic, or lumbar problems, and create entirely new problems.

SciFit machines are built on the notion of bidirectional resistance. This kind of resistance training exercises reciprocal muscle groups, increasing performance and reducing the risk of additional injury. Bidirectional resistance particularly helps when patients fatigue easily or face rehab walls. This type of movement allows patients to change directions of muscular output, resting one muscle group and working another, without interrupting the session. The PRO2 model allows for bidirectional resistance, and comes with seating for lumbar support and proper alignment, electromagnetic brakes for quiet operation, and step-through seat positioning. Other options for the PT from SciFit include the RST7000 Total Body Recumbent Stepper and the REX Total Body Recumbent Elliptical.

LifeFitness, Schiller Park, Ill, offers products focused on the benefits of independent loading in resistance training. Users unable to lift the same amount of weight with both limbs, due to injury or trauma, can be at more risk for injury with dependently loaded machines that don't identify muscle imbalances. Independent loading allows this imbalance to be immediately identified and corrected through training. LifeFitness offers a wide array of multiuse machines and systems for rehab and sports training.

NuStep®, based in Ann Arbor, Mich, offers the TRS 4000, which provides both upper- and lower-body motion, enabling users to work all the major muscle groups when building strength and improving overall cardiovascular fitness. According to NuStep, the TRS 4000 simulates a natural walking motion while eliminating undesirable joint stress and promoting functional fitness.

The Impulse Trainer, by Impulse Training Systems, Newnan, Ga, uses weights, pulleys, a slide track, horizontal movement, and inertia to teach patients coordinated movements and eventually increase speed. The weight moves horizontally, creating little resistance through gravity. Clients can move the weight in one direction, and then to slow it down, speed it up, and/or reverse it.

Michelle Park is a contributing writer for Physical Therapy Products. For more information, contact .

REFERENCE

1. American Heart Association. Resistance training is a good, safe addition for heart patients. http://www.americanheart.org/presenter.jhtml?identifier=3048982. Accessed July 17, 2008.