Strength Of Muscle Lab Report

Muscles in human body is like the motor which supports or assist the bones at the joints to move and work. When the muscle pulls it moves the bones at particular joints, which establish the joints to move about.

There are two main class levers being used during the lift. The 3rd Class lever is being used towards the lower part of the back since the athlete is bending over. The fulcrum is the lower part of the back, while the MAF is the shoulder area and the MRF is the barbell itself. The barbell is causing resistance in the opposite direction of the lift. Another lever that is being used is the 1st Class lever. This lever is being used twice in this lift. The first time is in the arms, the elbows are the fulcrum while the shoulder areas are the MAF and the barbell is the MRF. This structure also applies in the legs. The knees are

There are about 600 muscles in the body working together to create movement. Muscle contractions pull both ends of the muscle towards one another. One bone attached to each muscle is always more stabilized than the other. The less stabilized bone moves during muscle contraction due to the weaker stability. The points of attachment determine which bone will move. The least movable part is called the origin; it is the part that attaches closer to the midline of the body. This leaves the most movable part called the insertion. Each of these points can be identified in individual muscles to assist trainers in understanding how the muscles and joints work together to create motion.

The anterior deltoid is an agonist in the acceleration part of the throw its origin is the anterior border and upper surface of the lateral third of the clavicle its insertion is the deltoid tuberosity of humerus. The pectoralis major is also an agonist in the acceleration part of the throw its origin is the clavicle, the sternumand upper ribs, and the tendon of the external oblique muscle the insertion is the lateral lip of the bicipital groove of the humerus. The triceps brachii is an agonist in the acceleration part of the throw and an antagonist when the ball is being drawn back. Its long head origin is the infraglenoid tubercle of scapula, its lateral heads origin is above the radial sulcus, and its medial head is below the radial sulcus and its insertion is the olecranon process of ulna. The Infraspinatus is a synergist for the rotator cuff during the acceleration phase. Its origin is the infraspinous fossa of the scapula and its insertion is the middle facet of greater tubercle of the humerus. The biceps brachii is an agonist when the ball is being drawn back and an antagonist when the ball is accelerated forward. The origin of its short head is the coracoid process of the scapula and the origin of its long head is the supraglenoid tubercle of the scapula and its insertion is the tuberosity of the

The peak maximal force produced can be seen at 90/105 degrees and then begins to drop. When the knee joint angle reaches 165 degrees, the maximal force is at its lowest with volunteer 1 producing 119.1N and volunteer 2 producing 271.3 N. This is reversed for the hamstring muscles, which produce their lowest force of 80.83N and 331.9N for volunteers 1 and 2 respectively, at an angle of 75 degrees. The force produced then steadily increases until an angle of 150/165 degrees is met. Therefore, this test is useful in identifying the most widely used joint angles in a sport, allowing these muscles to be trained. It is reported in cycling, that peak force is produced for extension at 66⁰ and in flexion at 70.3⁰ (Brughelli et al. 2010).

As a physical therapist, I will need to help patients specific arears to repair tissues or muscle back to working conditions. In knowing what each motor unit and neuron does I can help my patients build that back. Also, the articles talk about making programs that help with movement which will be a daily thing for me. Considering I could have a patient with an ACL tear to a patient with a shoulder injury. I must individualize each of my programs around their rate coding and motor unit recruitment. It will also help me in designing effective training programs that will aid in helping them ease back into their daily activities or

When you flex your muscle it contracts, it gets shorter. If the opposite muscle is relaxed, it is longer. Think about your biceps and triceps, the muscles between your shoulder and elbow. Flex your bicep in the classic muscle man pose and it gets shorter. This contraction brings your forearm up because of where the muscle is attached to the bone. At the same time you have relaxed your tricep. When you relax your bicep and use your tricep muscle you cause the forearm to extend. The points of attachment to bone are the critical part of which muscle controls the movement of which bone. In this way muscles contract and relax which causes the other muscles to move in a certain direction, pulling the bone around with them. There are three types of Muscles contractions. These

Skeletal muscles rarely work by themselves to achieve movements in the body. More often they work in groups to produce precise movements. The muscle that produces any particular movement of the body is known as an agonist or prime mover. The agonist always pairs with an antagonist muscle that produces the opposite effect on the same bones. For example, the biceps brachii muscle flexes the arm at the elbow. As the antagonist for this motion, the triceps brachii muscle extends the arm at the elbow. When the triceps is extending the arm, the biceps would be considered the antagonist.

1. Why does the force begin to decrease with time? Note that a decrease in force indicates muscle fatigue.

According to the data of measuring EMG activity from antagonistic muscle, anterior muscles were more active during flexion than posterior muscles. Also, muscles were more activated when the hand is closed as opposed to open. Muscle flexion without a weight requires more force; however, muscle extension with a weight requires more force. Moreover, the muscle active increase in the heteronymous muscle during relaxation, which add stabilization and control to the movement. Doing the same experiment while a subject is running will increase the muscles force.

Humans have the ability for both gross and fine muscle movement that allows for powerful and exacting motions. Muscles are controlled by motor units. There are two sizes of these motor units, large and small. The larger units have larger motor neurons that innervate larger muscle fibers, while the smaller motor units have smaller motor neurons that innervate smaller muscle fibers. In addition, the larger units control perhaps, up to 1,000 muscle fibers, as in the thigh, while the small units might control 3-6 muscle fibers, as in the eye. In other cases, the number of motor units engage will vary; when less force is need while a little finesse is desired, for example. In the case of a large muscle such as a bicep, some fine movements

The first class lever is where the force and resistance is located between the fulcrum. An example of a first class lever is a seesaw. An example of a first class lever in the human body is the joint found between the skull and the atlas vertebrae of the spine. The second class lever has resistance force distributed between the axis and fulcrum. A wheel barrow or luggage with wheels on the bottom are examples of a second class lever. An example of a second class lever in the human body is located in the lower leg when someone stands on the tiptoes. The third class lever has the effort force in between the resistance force and the fulcrum. An example of a third class lever is an arm lifting a weight or a baseball bat as it swings to hit a ball.

In figure one it shows how a recruitment of a motor unit tends to work. The human body is required to have the recruitment of motor units in order for a muscle to contract because without it we wouldn’t be able to produce certain functions within the body. So when the recruitment is boosted then the contraction of a muscle will produce higher. Which is also vice versa if the recruitment was lower, then the contraction of the muscle will be produce less.

In a number of sports, the ability to produce a high muscular power output is required. Power is critical for the performance of sports that require quick changes in directions, jumping, and sprinting.1 To increase power production a number of plyometric exercises and programs can be performed. The theory of specificity plays a large role in deciding what plyometric exercises should be performed to improve power output.2 The theory states that the exercises should replicate the movement as closely as possible for the best results.1,3 Plyometrics are used to increase muscular power output and is accomplished by training the muscles to do more work in a shorter amount of time.1,4 The purpose of this report is to review the literature on the effects of plyometric exercises on power production.

In order for us to move, our bodies utilize its muscles to create movement. Muscles help with maintaining body temperature, supporting of soft tissue and skeletal movement. To do this, muscles must be able to contract during each movement. This lab session was completed in order for us to have a greater understanding of how muscles function and to find the relationship between muscle length and force. To better understand what events occur during muscle contraction, an electromyogram (EMG) was used to record the electrical activity of contracted forearm flexors at different angles of the wrist.