Normal spine has 3 curves in the sagittal plane: cervical lordosis, thoracic kyphosis, and lumbar lordosis. Biomechanically, the cervical, thoracic and lumbar spine are interrelated. Any postural changes in one segment influences the other two segments. In the human body, flexible segments cause the largest angle of movement. The thoracic kyphotic angle increases with age and the increase is greater in females than males. Normal kyphotic angles range between 20° and 40° and kyphotic angle more than 40° is called as hyper kyphosis. Posture is essential component of any body’s maximum effort to achieve with less efforts. It is said that “proper posture is believed to be the state of musculoskeletal balance that involves a minimal amount of stress and strain on bodyâ€. Although correct posture is desired, many people do not exhibit good posture. Postural changes, along with the associated local and global musculoskeletal problems that have been reported in the literature. It is also revealed that people sit more than 8 hours in a day. Sitting for extended periods maintaining awkward postures increases the risk to develop musculoskeletal and spinal problems. As a result of the increase in the use of the smartphones, students commonly report pain in the neck, shoulders and at the base of the thumb. Smart phone is correlated with increased flexion of the spine. The use of computers has been linked with musculoskeletal problems. Maintaining an unideal posture may result in the development of postural problems such as excessive thoracic kyphosis and a poking chin, which in turn will result in inadequate muscle contractions, weakening of postural muscles and fatigue. The most common postural abnormalities that occur in most sports are scoliosis and kyphosis. Researches have shown that professional cyclists have higher degrees of kyphosis compared to amateur cyclists. Increase in kyphosis may be attributed to an alteration in the intervertebral disc and endplate height, a loss in the anterior vertebral height and an imbalance in the supporting anterior and posterior soft tissues and musculature. Biomechanical data suggest that an increase in the thoracic kyphosis may be associated with significantly higher spinal loads and trunk muscles force in an upright stance and this might accelerate the degenerative process and constitute to dysfunction and pain. Kyphosis is the primary thoracic curve of the vertebral column and is composed of 12 vertebrae. Increased kyphosis can cause severe postural deformity, which results in both shorter stature and a downward gaze. These changes can affect activities that benefit from upright posture or exercise tolerance, such as walking, stair climbing, household works, or overhead reaching activities. An increased thoracic kyphosis is associated with diminished physical function, impairment in respiratory function, increase in cervical pain, headache and discomforts in shoulder such as sub acromial pain. The gold standard method for measuring the thoracic kyphosis is the cobbs angle method which can be calculated from X-ray images. Cobbs angle is defined as the greatest angle at a particular region of the vertebral column when measured from the superior endplate of the superior vertebrae to the inferior endplate of an inferior vertebrae. However, this method is found to be expensive for the patients as well as this method involves radiation exposure, it is rarely clinically indicated. A flexi curve ruler is a tool that can be used to assess the curvature of the spine. It is a strip of flexible metal covered in plastic which can be placed at the top of the back and gently bent so that it reflects the shape of the backbone and then the particular curve can be traced onto the plain sheet of paper. Flexi curve is easier to use, convenient, lightweight, less expensive and provided more accurate and reproducible results than inclinometer. Grip strength is the strength of the fingers while holding something, it is useful and an important index in the evaluation of motor function of the hand. The grip strength is strongly related to muscular strength, so it is used to evaluate changes in muscular strength. Grip strength is not only force generated by the fingers and wrist joint, it is also connected to muscular strength of forearm, brachial and shoulder joints. According to recent studies, Jamar hand dynamometer is the most reliable and accurate device for measuring the handgrip strength. Increase in kyphosis affects the shoulder muscles where there is increased tension in pectoralis major, pectoralis minor and subclavius muscles. When there is alteration in scapular stability the hand function will be affected. Scapular protraction is seen in increased kyphotic posture as a result of pectoralis minor tightness which can lead to altered scapulohumeral rhythm dissociation and in turn compromises the rotator cuff stability. When scapula fails to stabilize, the shoulder complex function will be inefficient leading to impairment in upper extremity chain. For the upper extremity tasks to be effective, the links of the kinetic chains must be having optimum strength, flexibility, proprioception and endurance. So, if any impairments are there in the kinetic chain it can lead to altered biomechanical output. Increased kyphosis leads so muscular imbalances of kinetic chains in the upper extremity. Thus, any changes and disequilibrium in these kinetic chains may account for upper extremity strength. Hence, the aim of the study is to find out the correlation of thoracic kyphotic angle with hand grip strength in healthy adult population. OPERATIONAL DEFINITION: Kyphosis - Kyphosis is a normal curvature of the thoracic spine, marked by a small anterior concavity resulting from the shape of vertebral bodies and intervertebral discs.
RESEARCH QUESTIONS ØIs there a difference in handgrip strength measurements in subjects with varying kyphotic angle? ALTERNATIVE HYPOTHESIS (H1): There will be a significant difference in handgrip strength measurements in subjects with varying kyphotic angle. NULL HYPOTHESIS (H0): There will be no significant difference in handgrip strength measurements in subjects with varying kyphotic angle. |