Repetitive arm use can cause fatigue of shoulder muscles and this has been a potential link to the development of shoulder pain. A reduction in force generation of shoulder muscles might lead to a reduction in control or stabilization for joint motions, such as the GH joint. The infraspinatus has been seen to play a significant role in the alteration of GH kinematics when fatigued while other shoulder musculature, such as the anterior/posterior deltoid and serratus anterior, did not alter GH kinematics while fatigued. Altered scapular kinematics have been found after fatiguing external rotators such as the infraspinatus. decreased scapular posterior tilt, upward rotation, and external rotation during arm elevation after the external rotators were fatigued. confirmed a decrease in scapular posterior tilt from external rotator fatigue, but also noted an increase in scapular upward rotation at 60° of arm elevation. also stated an increase in scapular upward rotation with arm elevation following fatigue. …show more content…
Subjects were asked to alternate between holding external rotation of 0° while blindly identifying objects by hand using touch followed by 20 repetitions of shoulder external rotation against resistance, and then raising their hand until their forearm was parallel to the floor and lowering the arm while holding a weight that was 20% of the force produced in the MVC (for example, if they produced ten pounds of pressure the weight would be two pounds). Fatigue was determined when subjects were unable to continue the required activities and force was decreased by at least
Many factors like patients age, symptoms, size of the tear, and nature of onset (traumatic or degenerative) are responsible for determining the prognosis of the physical therapy treatment 9. Since it’s a partial thickness tear of the rotator cuff, the non-operative treatment is reasonable unlike, a full thickness tear where surgery will be required to treat the patient 9. The patient shows symptoms of moderate irritability without significant functional deficit which makes him a good candidate for conservative treatment 10. The pain reported by the patient is 6/10 so the patient participates well in physical therapy exercise to increase shoulder strength, and flexibility. There was a study done from Finland which asserted that physical therapy alone can produce results which are equal to those produced by arthroscopic surgery and open surgical repair in cases of rotator cuff tears 11. In this case, with three weeks of physical therapy the patient has showed a decrease in pain and reported it as 4/10 on pain rating scale and showed improvements in abduction (140̊) and external rotation (65̊). The MMT for shoulder abduction was 4-/5 and external rotation is still same as
The subject’s forearm was prepared by cleaning the surface of their skin (the flexor digitorum superficialis muscle) and the bony prominence of their wrist with an alcohol swab, and the EMG adhesive electrodes where placed on the belly of the flexor digitorum superficialis muscle. The positive electrode was placed more proximal to the elbow, while the negative electrode was placed more mid-distally. The grounding (noise reducing) electrode was places on the bony prominence of the wrist, and the force transducer was setup to achieve a stable baseline. The subject was then instructed to the support their forearm over the edge of the table or on their leg with the wrist in a semi-flexed position, and when ready squeeze the force grip transducer as hard as possible. For the first/”fast” time interval of the experiment, the subject made ten squeezes as fast as possible with one second per squeeze intervals, and the force onset, EMG onset, difference between force onset and EMG onset, peak EMG amplitude, and peak force amplitude were observed and recorded. The experiment was then repeated for a medium, three seconds per squeeze, and slow, five seconds per squeeze time intervals with the same variables observed and
A rotator cuff is simply a group of four tendons and muscles that are located right on the shoulder and on top of the humerus bone. (Source 1) The rotator cuff is what controls the shoulder and allows it to move and be mobile. The four main muscles that consist of the tendons are the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. (Source 2). Too much wear and tear on these muscles (such as too many thrown fastballs) is precisely what causes the rotator cuff to begin to tear, as well as swelling in the tendons.
Kinesiology can be defined as the study of mechanics of body movements, so I think that is very important to know the meaning of movement when studying kinesiology. Everything in kinesiology has to do with the movement. Every action the body takes is a movement which is what kinesiology is. You cannot be successful in the field of kinesiology no matter what you are doing if you do not understand what movement is. It is the study of human movement, performance, and function by applying the sciences of biomechanics, anatomy, physiology, and neuroscience. It looks at movement and which muscles are involved to create movement relating to strength exercising and sports technique. Movement is an act of changing physical location or position or of
“The doctor of the future will give no medication, but will interest his patients in the care of the human frame, diet and in the cause and prevention of disease” by Thomas A. Edison. Chiropractors use hands-on spinal manipulation and other alternative treatments on the spine which will enable the body to heal itself without surgery or medication. Chiropractic care began in 1895 when its founder, Daniel David Palmer, claimed any and all diseases could be healed by nothing more than just his hands. Dr. Palmer examined a janitor who was deaf for 17 years after the janitor felt his back was out of place, so Dr. Palmer gave an adjustment to what was felt to be a misplaced vertebra in the upper back. The janitor then observed that his hearing improved thanks to Dr. Palmer. Chiropractors use manipulation to restore mobility to joints restricted by tissue injury caused by sitting without proper back support. Chiropractic is primarily used as a pain relief alternative for muscles, joints, bones, and connective tissue, such as cartilage, ligaments, and tendons. About 22 million Americans visit chiropractors annually
The effects of perceptual load on the occurrence of inattentional blindness were demonstrated clearly by experiment. In an experiment conducted by Finch and Lavie in 2007, participants were given identical series of central cross-targets with two arms of clearly different color (blue and green) and slightly different length. Participants were split in two groups, one performing an easy task (low load condition) and the other a harder task (high load condition). The group performing the easiest task only had to make color discrimination between the tw...
Proprioception provides an awareness of the body and body positioning without 'continuous reference to consciousness' (Lephart et.al, 1997, p. 131). There are two types of proprioception, being conscious and unconscious. Conscious proprioception concerns joint position sense and kinetic sense (Khasnis & Gokula, 2003). Joint position sense processes joint movement and joint position sensations (Sharp et.al, 1994). These joint sensations provide the awareness of the position of the body and body parts in space (Khasnis & Gokula, 2003). Kinetic sense is the awareness of the motion of various body parts (Khasnis & Gokula, 2003). Joint position sense and kinetic sense are essential for proper joint function in daily activities. Mechanoreceptors are peripheral afferents and transmit signals that the joint position and kinetic senses identify (Lephart & Fu, 1995). Mechanoreceptors are located in spindle endings and tendonn organs in muscles, or Ruffini spray endings in deeper tissue (Stillman, 2002). Mechanoreceptors can act at different speeds, and conscious proprioception can pl...
Controlled increases in physical stress through progressive resistive exercise cause muscle fibers to hypertrophy and become capable of generating greater force.3 Early emphasis is on restoring joint range of motion and muscle flexibility, however, resistive exercises are not delayed. The initial emphasis of muscle loading should be on endurance, accomplished with lower loads and higher repetitions. Progressive resistive exercises are initiated at the available range and progressed to new positions as wrist range of motion returns in all planes. Both the overload principle and the SAID Principle (Specific Adaptation to Imposed Demands) are important considerations in therapeutic exercise dosing.1,3,11 Within pain tolerance, dosing progressive resistive exercises that maintain a therapeutic stress level will encourage muscle tissue hypertrophy. Finding activities that produce the correct force and repetition, without injury, is the goal of the remobilization period. Starting with low force, moderate to high repetitions, and encouraging therapeutic rest following induced stress is important to both the overload principle and the SAID Principle. Additionally, it is important to prevent dosing resistive exercises that exceed optimal stress, which may result in injury. The patient’s response to therapeutic exercise should be assessed during, immediately following,
This lab explored the relationship between EMG and force and EMG and fatigue. It has been shown that EMG, fatigue and force levels are dependent upon type of contraction and whether or not the contraction is maximal or sub maximal. Seliger et al. (1980) gained insight into the differing force and EMG profiles of isometric, eccentric and concentric contractions. Fourteen subjects underwent a maximum voluntary contraction in the squat of the concentric, isometric and eccentric variations. He showed that the EMG activity in the rectus femoris showed little statistical difference. However the force reading showed its highest values during an eccentric contraction, it's lowest values during concentric contractions and its second highest values during isometric contractions (Seliger, 1980).
This case involved a 53 year old man who sustained a significant tear of his rotator cuff while playing baseball. He underwent surgical repair and was given a referral for physical therapy. The referral was to begin passive ROM 3 times per week for 2 weeks then initiate a supervised home program of active exercise for 2 weeks, and elastic resistance exercises for internal and external rotation every other day for a month. 2 weeks after surgery, he had his first PT visit in a sports medicine clinic that was managed by an athletic trainer (ATC).”
In the mental rotation task, subjects are pre- sented with pairs of 2-D or 3-D shapes, and asked whether they are mirrored or non- mirrored.
Athletes must accomplish amazing feats of balance and coordination of the body. As scientist, Mikhail Tsaytin discovered in the 1970s, acrobats can successfully make a two person human tower in the dark, but after adding a third acrobat, not even the most talented can maintain the balance required to keep the tower intact while in the dark (1). What does darkness have to do with it? The point is that balance relies on at least three signals coming from the body, and one of those is sight. Once you eliminate one of these signals, the body cannot accomplish the required task. In addition to sight, signals coming from muscles and joints, called proprioceptors are sensitive to changes in position. The third contributor to the human tower and the topic of discussion of this paper is the vestibular system. A three-person human tower in the dark must not have enough information coming from the vestibular and proprioceptive systems to function without vision, whereas the two-person tower did have enough information.
When performing manual muscle testing for shoulder flexion and abduction, PTA’s typically place their hand at the wrist verses the mid-extremity because placing their hands at the wrist increases the length of the lever thus testing the muscles ability to resist externally applied force overtime and across the bone-joint lever arm system. Shorter lever arms will provide higher testing scores when compared to using longer lever arms, thus changing the point of force application affects the length of the lever arm and therefore the muscle torque.
The shoulder is one of the most complicated groupings of joints, tendons and muscles in the body. No one knows that better than shoulder doctor McLaughlin, who has operated on both shoulders on more than 200 patients. Using cutting-edge
[3] H. S. Milner-Brown, R. B. Stein, and R. Yemm. "The Orderly Recruitment of Human Motor Units during Voluntary Isometric Contractions." The Physiological Society 230th ser. (1973): 359-70. Web. 22 May 2014.