Changes That Take Place in the Human Locomotor System - Case Study Example

HUMAN LOCOMOTION SYSTEM One of the certainties in humans is that they grow older day by day. The people are getting aged and this affects the variousdimensions of the life. So in order to prevent aging soon, chronic and systematic exercise along with good habits should be practiced. The exercises increase the longevity of the life in humans. Of those exercises, walking occupies the first place. While walking, the lower body and also the backbone are given movements and this helps to improve their activity level. The skeletomuscular system is the foundation of the body. It provides strength and structure to the body. For locomotion or walking, the skeletal muscles and bones work as a functioning unit. Thus skeletomuscular system contributes to locomotion. Our ability to perform the regular activities is contingent on our ability to control the multiple dimensions such as posture, balance and locomotion. The balancing of the body refers to the control of the centre of mass (COM) with respect to the base of the support. (Spirduso et. al, 2005). According to the human postural control systems theory, the bodily orientation and locomotion are controlled by multiple systems in the body. The important systems include motor, sensory and cognitive systems. The sensory system involves in processing the information. The motor system is involved to movement of the body. The cognitive systems are the structures that determine the mental processing of the human. The systems will perform based on the goal and on the environment in which it is performed. As the human passes from one stage to other, a number of changes occur in the sensory, motor and cognitive systems. BIPEDALISM: The process of using two feet for locomotion is called bipedalism. It mainly occurs in terrestrial locomotion. The various types of bipedalism includes walking, running etc. The bipedal movement requires a number of adaptations in mechanics and neurology. The mechanical adaptation says that bipedalism is a type of walking and running. Another important requirement of bipedalism is the long, strong legs with high musculature. The muscles of the thigh are very much important for the good bipedalism. A biped must have a good breath whilst running. The most important requirement for bipedalism is the neural network. (Berg, 1999). The nerves must send the impulses so quickly that they must respond before they fall down by loosing the rigidity. Thus neurological system is very essential. The advantages of bipedalism are improved vision; the raised head helps the individuals to have a good detection of various aspects including the distinct dangers. To obtain the maximum benefit a limited and executive bipedalism is required. LOCOMOTION: The ability to move about successfully in a variety of environment using the muscular and skeletal system is termed locomotion. The associated organs are bones, muscles, tendons, ligaments, cartilage, joints and the connective tissue the successful locomotion is dependant on the ability of the body to control the upper and lower body limb movements. The locomotion requires energy to overcome the forces of gravity, inertia, drag and friction. The locomotion can be at three levels: terrestrial, water and air. The terrestrial locomotion includes walking, running, crawling, jumping and slithering. In walking, there are several step processes. The running is a continuous process. For these motions to be effective the support of skeletal and muscular framework is required. At infant stage, the motion of the human is by crawling. This locomotion does not play very important roles as they last only for a short time. The next stage is walking. Walking is characterized by the alternate steps of the right and left lower limbs. The lower limbs are the weight bearers of the whole body. The movement of the lower extremity includes the movement of the hip joint, knee joint, ankle joint and the foot. The rhythmic alternation of the two lower limbs constitutes the forward movement of the body. This pattern of movements of the limbs in the humans is called as gait. GAIT CYCLE: There are two phases in gait cycle - the stance and the swing phases. At the stance phase the foot is in the ground (the stance phase begins when the heel contacts the ground and ends when the toe leaves the ground) and at the swing phase the foot gets lifted and moves forward (the swing phase begins when no longer the foot is in the ground. The limb is free to move). (Patla, 1991). The total duration of the stance and swing phase constitutes one Gait cycle. The characteristics of the gait are influenced by the shape, position and function of neuromuscular and musculoskeletal structures. CHART - THE MAIN TASKS AND DIVISIONS OF THE GAIT CYCLE. (Huang, 1999) The walking is the most common form of gait. A complete gait cycle is viewed in terms of three functional tasks: weight acceptance, single-limb support and limb advancement. Analyzing the gait cycle helps us to understand the locomotion of the humans. The locomotion of human has idiosyncratic characteristics with unique features. The gait analysis helps the athletes to run fast and to identify the posture related problems in injured people. The gait helps us to identify our family and friends too. Every individual have their own gait characteristics. The locomotion of human varies as aging occurs. Though it is difficult to know whether the changes that occurs in the gait cycle contributes to the aging process or not, it is clear that the gait pattern varies between old people and younger ones and also when there is a change in the posture control system. The variation is mainly in the gait speed. Age related changes also affect the sensory, motor and skeletomuscular system. This in turn affects the gait cycle. (Patla, 1991) Summary of Age – Associated Changes in Gait Pattern Temporal and distant variables Kinematic variables Decreased velocity Decreased step length Decreased step frequency Decreased stride length Increased stride width Increased stance phase Increased time in double support Decreased time in swing phase Flatter foot floor pattern Reduced arm swing The altered gait patterns are due to muscle weakness, impaired motor control and pain. These altered patterns increase the energy expenditure of the individual and creates a pathological gait pattern. Deviation from the gait pattern is observed in both stance and swing patterns. If the case is so then the skeletomuscular factors must be evaluated systematically. (Delisa, 1998) METHODS OF ANALYSIS OF GAIT: Most probably the observational gait analysis is most probably enough to characterize the gait pathologies. 1) Instrumental motion analysis is a logical extension of the gait analysis. The markers that bind to the bones are used here. The markers are made to reach the bones and joints and then the motion of the limb segments are analyzed and recorded. (Delisa, 1998) 2) External forces – the calculation of the joint moments are done by using torque, kinematics and body segment parameters. 3) Dynamic Electromyography – it is a device that measures the movement of the muscles indirectly. 4) Mechanical and metabolic efficiency – the changes in the mechanical work and the energy expenditure and the rate of use of internal and external work are calculated. From the efficiency of the work the gait is analyzed in the individuals. EFFECT OF AGING ON LIGAMENTS: The ligaments are found n the lower extremities at the midtarsal, subtalar and knee joints. The ligaments are responsible for weight bearing and balance the body mass in motion. The Pathological gait patterns affect the arm levers. The stress that is caused by the pathological gaits alters the magnitude of the arm lever forces. Due to this stress, the ligament laxity occurs at the midtarsal and subtalar joints. As a result the ligaments are severely injured and this alters the normal daily activities of the individuals. Due to the fact that they can’t return back to the neutral joint with the previous alignment and the weight bearing effect of the lower extremities reduces and causes abnormal gait. The ligamentous laxities occurring at the knee joint usually do not progress because of the lost of ankle and foot rigidity at the midtarsal joint. The ligamentous laxities can even lead to malfunction of the skeleton. (Spirduso et. al, 2005). Hence the factors damaging the ligament should be identified and removed before it causes severe effects to the gait cycle of the human. EFFECT OF AGING ON SKINS: It is the most closely watched organ of the body. The general appearance of the skin is used to estimate the overall health and the age of the person. The aging causes the thinning of the epidermis and dermis layers, reduces the blood supply to the skins, the decreased activity of the sweat glands and oils out of the skin through pores. Due to the decrease in the activity of the sweat glands, the old people are not able to dissipate the heat from the body. Aging also causes the breakdown of the collagen and the Elastin fibers. As a result the normal gait is affected. EFFECT OF AGING ON MUSCULOSKELETAL SYSTEM: The musculoskeletal system must provide very strong bones and well functioning joints with adequate muscle strength for a normal gait. The muscle tone is controlled at the sub cortical level. Normal muscle tone is very important as it is required high to resist gravity and low for the movement (Keen, 1993). The normal gait requires proper functioning of the skeletomuscular and nervous system. If the abductor muscles are paralyzed the condition is termed as Trendelenburg gait. As aging occur, the muscle bulk, strength, rigidity and flexibility gets reduced. The loss of the strength on the muscles at the lower extremities in the elderly impairs the locomotion and increases the chance of falling. It is also found that the adults after the age of 70, they get trouble to walk with a very less amount of load with them. as aging proceeds the strength of the muscles, the joints rigidity, the bone strength , the vision , the reduction of dermal layer all together contribute to the abnormal gait in the humans. High velocity resistance training on maintaining and improving muscle power in the adults can bring the reduction of the muscle strength back. (Delisa, 1998). WALKING ABNORMALITIES: The different types of walking abnormalities are caused either wholly or partially by the physical conditions. 1) Propulsive gait- this is a stooped rigid posture observed as having head and neck bent forward. 2) Scissors gait – the occurrence of flexing of the legs and knees, giving the appearance of crossing in a scissors like manner. 3) Spastic Gait- a dragging walk of the person due to the one –sided, long term muscle contraction. 4) Steppage Gait – improper foot alignment while walking. 5) Waddling Gait – the duck-like walk (Kantor, 2007). EFFECT OF DISEASES ON GAIT: Gait abnormality occurs due to the dysfunction of the skeletal and muscular system. Even very small changes in the neurological control mechanisms, structural skeletal alignment and motor input will have a greater effect on the dynamic stability and functioning of the efficient gait. Gait abnormality is prevalent with the people who suffer from Parkinson’s disease, Alzheimer’s disease, Myasthenia gravis, Multiple sclerosis and peripheral neuropathy. (Bateni and Olney, 2004). The people with this abnormality gait have a chance to get recovered from it with in a year or so depending upon the onset condition of the disease and by the treatment methodologies. GAIT AND CNS FUNCTIONS: The motor system is also an important factor for normal locomotion and gait. The neural network is important to transmit the commands and to process it. The most common framework for identifying gait disorders is based on neurologic diagnosis. We can also classify the gait disorders based on CNS function as a hierarchy with low, middle and high level of sensimotor functioning. The low level sensimotor functioning causes gait disorders arising from the disturbances in the peripheral functions. (Bogey, 2001) Middle level sensimotor dysfunction causes stroke to Parkinson’s disease and creates faulty posture and locomotors patterns. The high level disorders are less understood. The middle level disorders are found to be high when compared to the other three. The development of physiological process affects the neuromotor control, rotation of the limbs and joints by an axis, maturing and growing of bodily segments and changes in posture. (Fish and Nielsen, 1993) PATHOMECHANICAL GAIT: The abnormal effect of the static and dynamic forces on a human body is affected by neurological, skeletal and muscular disorders. The failure to return to normal state of the neutral joint angulation’s alignment lower limbs at the perfect joint levels is called as pathomechanical gait. (Keen, 1993). CONCLUSION: Life is described in terms of quality and quantity. Quantity is described as the maximum lifespan potential. The crawling is the first form of locomotion. The next form of locomotion is walking. This form of locomotion is the major one in the life of humans. The walking is also called as gait. Each and every individual have their own pattern of gait. The gait will be normal until the physic of the individual is normal. When there occurs a change in the gait due to natural (i.e. aging) and forced actions the abnormality occurs. For many older adults, age and pathology associated changes occur frequently. As a result the multiple systems that control the balance and locomotion frequently fall. REFERENCES: Bateni, H and Olney, S J, 2004, Effect of the weight of prosthetic components on the gait of transtibial amputees, Journal of prosthetics and orthotics, 16, 4, 113- 120. Berg, B, 1999, The Gait Cycle, http://www.upstate.edu/cdb/grossanat/limbs6.shtml: Date accessed 27/4/2009 Bogey, R, 2001, Gait analysis, Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, Delisa, J A, 1998, Gait analysis in the science of rehabilitation, Baltimore: Department of Veterans Affairs. Fish, D and Nielsen, J P, 1993, Clinical Assessment of Human Gait, Journal of prosthetics and orthotics, 5,.2, 39- 48. Huang, A., 1999, Gait disorder project, http://sprojects.mmi.mcgill.ca/gait/normal/intro.asp: Date accessed 27/4/2009 Kantor, D, 2007, Walking Abnormalities , http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/003199.htm: Date accessed 27/4/2009 Keen, M, 1993, Early Development and Attainment of Normal Mature Gait, Journal of prosthetics and orthotics, 3, 2, 35- 38. Patla, A E, 1991, Adaptability of human gait, Elsevier Science publishers, North Holland. Spirduso, W W., Francis, K L and MacRae, P G, 2005, Physical Dimensions of Aging, Second Edition, Human Kinetics. Read More