Hand- Grip Dynamometer
Hand-Grip dynamometer are used to measure the strength and endurance of the muscles in your forearm, and to a lesser extent your hand. Using a handgrip dynamometer will increase your performance at work, improve posture, decrease chances for injury, and prevent low back pain. Endurance is the ability of a muscle to work for long periods of time without extreme fatigue. It prevents unwanted fatigue from daily activities, sport and recreation. For the elderly person, good hand grip strength may prevent a fall down stairs or in bathtubs and may help people from dropping jars. It could help the elderly with opening jars as well.
Three area’s of rationale are used to measure strength-anatomical, physiological, and biochemical. These are all interrelated. The first area Anatomical Rationale-Hand grip strength is mainly a function of the muscles in the forearm, and hand. Eight muscles serve as the prime movers and stabilizers in hand grip strength. Eleven other muscles assist in contraction of the hand.
The second is physiological Rationale which has six categories. Six of the most common measurement terms in physiology are mass, force, work, velocity, power and energy.
The third area is biochemical rationale exercise may be divided into three categories based upon the predominant metabolic pathway. The primary biochemical reaction for strength, or any muscle contraction is ATP ( Adenosine Triphosophate).
The muscular strength is highly affected by the nervous system. Emotional and mental factors play important part in strength testing. If a subject is consistent with motivation strength variability should be minimized. In women a daily variation in strength range is between 2 and 12% and 5 to 9% in men.
Instruments used to measure muscle strength are cable tensiometer, dymameter, free weights, barbells, isokinetics devices and load cells or elechromechanical devices. Strength is usually measured in units of force or torque. Kilogram (kg), and pounds (lb), is the force unit. The torque unit may be expressed as a foot-pounds (fl-lb) or Newton meters (nm).
The procedures for handgrip strength testing are:
1. The subject should be in the standing position.
2. The subject’s head should be in the midposition (facing straight ahead).
3. The grip size should be adjusted so that the middle finger’s midportion is approximatrely at a right angle.
4. The subject’s forearm may be placed at any angle between 90 degrees and 180 degrees of the upper arm; the upper arm is in a vertical position.
5. The subject’s wrist and forearm should be at the midprone position.
The only other strength of the experimental design was that its validity was reasonably high. This experiment directly tested the effect of prior exercise on muscle fatigue during physical exercise
In lab, isometric handgrip strength was tested. Isometric strength refers to the type of force that occurs when muscles generate force, but its length remains unchanged. This can also be called a static muscle contraction. A static contraction occurs when one tries to lift an object that happens to be heavier than the force applied to the muscle or a static contraction occurs when one supports the weight of an object by holding the object steady with the elbow flexed. In both of these examples, the person feels their muscles tense but the joint does not move (Kenney, Wilmore, & Costill, 2012). Handgrip strength reflects the importance for successful performance in activities of daily living and occupational activities (Beam &
Weight – Three commonly used metric units for weight are the kg, g, and mg.
As we have learned through our reading, most all bodies skeletal muscles are made up of primarily three types of skeletal muscle fibers, but their proportion differs depending on what action the muscles is doing. For example, type I fibers such as muscles of the neck, back, and leg have a higher proportion. According to Quinn (2014), type I muscles are slower and more effective, they tend fire a lot slower than fast twitch fibers and they fatigue at a much slower rate. Hence, slower twitch fibers are pronounced at helping athletes run marathons and bicycle for hours. Shoulder and arm muscles are not always active but are intermittent in their use; these muscles tend to have a larger amount of tension for uses in throwing and lifting. These muscles have a combination of both type I and type II B fibers. These fast twitch fibers use anaerobic metabolism to create energy and are the "classic" fast twitch muscle fibers that excel at producing quick, powerful bursts of speed. These muscles are used in events such as 100m sprint, basketball, soccer and football. Since this muscle fiber fires at such a high rate of contraction it will fatigue much faster and will not last long before needing to rest.
Broer was the first to call attention to the similarity of movement patterns used in seemingly dissimilar activities such as the baseball pitch, the badminton clear, and the tennis serve. Objective evidence of such similarities between throwing and striking activities within each of the three major upper-extremity patterns; overarm, sidearm and underarm. The representative activities from these categories across throwing patterns also showed great similarity in the muscular action of the lower extremity. Atwater distinguished between the overarm and sidearm throwing patterns in terms of the direction in which the trunk laterally flexed. When lateral flexion occurred away from the throwing arm, and overarm pattern was used; lateral flexion toward the throwing arm indicated a sidearm pattern. The underarm patter is distinguished by motion predominantly in a sagittal plane with the hand below the waist. Each pattern involves a preparatory movement referred to as a backswing, or windup, followed by the establishment of a base of support prior to the initiation of the force phase and ending in the follow-through. The base of support in the direction of the force application; forward and backward is a distinguishing feature of skill level. It has been well documented that more highly skilled individuals have longer strides. Once the base has been established, the more proximal segments begin the force application phase while the more distal segments complete the backswing.
Muscle endurance is the ability to perform a lot of repetitions against a given resistance for a long period of time. The combination of strength and endurance results in muscle endurance. Muscle endurance is used in may sports such as rowing, swimming, cycling, distance running, field hockey and American football. Normally, an endurance muscle program involves lifting about 12-25 repetitions of moderate loads. In some cases, this is inadequate for many sports such as boxing, canoeing and x-cross skiing.
Some of unfamiliar units that are used in this lab are Joules, calories, and Calories. All of these units measure energy, heat, and work.
The muscles in our body perform various functions such as helping with blood circulation, digesting food, and moving parts of the body. The three types of muscles cells found in the body are the cardiac, smooth, and skeletal muscle cells. The purpose of this lab was to determine the relationship between muscle force and EMG activity, and to examine the effects of muscle size and muscle force. In this lab, we used iWork physiology kit to record the bursts of muscle action potentials during a muscle contraction which is also known as an electromyogram (EMG). We then used this data to compare the maximum muscle force, half-maximum muscle force, and the half- maximum fatigue time to a person’s forearm circumference (muscle size).
First is contractility, the ability to contract or shorten in length. This causes increased tension between the ends of the muscle. Because of contractility, the length of muscles can decrease, increase, or stay the same. Next is extensibility, meaning that muscles have the ability to stretch when pulled. They are able to react positively to a force. Muscles also respond to stimuli like nerve impulses, a characteristic is known as excitability. Stimuli, whether external or internal cause muscles to contract. Last is elasticity. Muscles are said to have elasticity because they return to original size and shape after being extended or
[2] Zelick, R. 2014. Muscle Lab Exercise. Bi253 Lab Manual. Portland State University, OR, pp. 1-5
Van Roie, E., Delecluse, C., Coudyzer, W., Boonen, S., & Bautmans, I. (2013). Strength training at high versus low external resistance in older adults: effects on muscle volume, muscle strength, and force-velocity characteristics. Exp Gerontol, 48(11), 1351-1361. doi: 10.1016/j.exger.2013.08.010
There also are alternative kinds of devices known as Hand Exercise Devices. These devices are applied to a minor injury stroke patient or to the non-stroke humans for the purpose of travail maintain flexibility and power.
Strength is an abstract concept with various meanings. Some meanings are more complex than others. Many people when they hear the word strength think of muscular men who can lift cars or comic book heroes that fly around their city saving people. More exists to the concept than just being muscular. Strength is also shown when one goes through something tough but stays positive and pushes through it anyways. Having strength can mean possessing the ability to accomplish hard tasks because of muscles, being firm or solidly planted in something, or withstanding your own and not giving up or giving in to the opposing force.
Dunn, George et al. National Strength and Conditioning Association. National Strength and Conditioning Association Journal. 7. 27-29. 1985.
Gabboth, Tim. "Journal of Strength & Conditioning Research (Lippincott Williams & Wilkins). Feb2012, Vol. 26 Issue 2, P487-491. 5p." N.p., n.d. Web.