Strength is defined as the quality of being strong or powerful as it relates to muscular activity. Muscle strength is needed to perform daily activities. Weakness can decrease function. People with MS often report weakness or lack of strength as a problem. Strength can be affected by fatigue, spasticity and limitations in range of motion. Strength training is designed to improve muscle power, bone strength (decrease the risk of osteoporosis), physical capacity for daily activities and prevent injury. Additional benefits for people with MS may be increased endurance (delaying the onset of muscle fatigue), increased strength which can help with posture, balance and movement. The primary goal of strength training for people with MS is to improve strength and endurance due to deconditioning.
The first step in determining an appropriate strength training program is identification of the muscle weakness. Your physician, physical therapist, occupational therapist and/or exercise physiologist can measure muscle strength (and weakness) to help guide your strength training program.
Testing for muscle strength is done through different means. The most common method of measuring muscle strength is the manual muscle test (MMT). The MMT consists of moving a body part through range of motion with resistance applied. Muscles are rated on a 0-5 scale with 0 being no muscle contraction and 5 being full movement with normal resistance.
Other means of measuring muscle strength include hand held dynamometers, isotonic measures and isokinetic measures. Hand held dynamometers provide objective measures of an isometric contraction (contraction of a muscle without movement). Isotonic measures include measurement of the amount of weight which can be lifted in a set number of repetitions. For example, a one repetition maximum (1RM) is the total amount of weight one can lift for one repetition, while a 10 RM is the amount one can lift for 10 repetitions. Isokinetic measures are measures taken when the resistance is variable throughout the range of motion. These measures require the use of specialized equipment. The graphs produced provide information on muscle strength and endurance.
Once muscle strength has been evaluated, a strength training program can be established. There are different types of resistance which can be used to strengthen specific muscles or muscle groups. Free weights, weight machines, elastic tubing, water (pool exercises) and manual resistance are common modes of strength training. For individuals who have significant difficulty, the use of gravity as a form of resistance can be effective. The amount of resistance is determined by the strength assessment and the goals of the strength training program.
The frequency of the strength training program is also dependent upon the goals of the program. It is important to work within symptoms, particularly fatigue. The usual recommendation for strength training is 2-3 days per week. It is important to allow rest in between strength training to allow for adequate muscle recovery. If training on successive days it is important to alternate muscles or muscle groups unless otherwise instructed by your physician, physical/occupational therapist or exercise physiologist.
Some tips for success in your strength training program are:
• Identify the goals of your strength training program; consult a physician, physical therapist, occupational therapist or exercise phyisologist for assistance and identification of appropriate strength training exercises.
• Perform exercises through a full range of motion; this will help reduce the risk of injury to muscles, tendons and joints
• It is not necessary to work your muscles to the point of fatigue
• Don’t be impatient. Allow yourself adequate time for recovery between sets of exercises if doing more than one set of exercises per muscle or muscle group.
• Be practical. Plan your strength program so you don’t fatigue yourself to do the things you enjoy.
Strengthening exercises are important as part of a comprehensive exercise program. It is important to identify appropriate exercises before initiating your program. Your healthcare team can be helpful in establishing an individualized program to meet your needs.