Biomech Analysis of Movt
Biomech Analysis of Movt KINS 3134
Popular in Course
verified elite notetaker
Popular in Kinesiology
This 51 page Class Notes was uploaded by Lizeth Nicolas on Monday October 12, 2015. The Class Notes belongs to KINS 3134 at Georgia Southern University taught by Barry Munkasy in Fall. Since its upload, it has received 29 views. For similar materials see /class/222002/kins-3134-georgia-southern-university in Kinesiology at Georgia Southern University.
Reviews for Biomech Analysis of Movt
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/12/15
Projectile Motion Introduction In many sport activities the performer moves freely through the air Diving gymnastics high jumping long jumping and gure skating are a few examples In addition sport implements are projected in events like shotput discus throwing and baseball In both cases movements are classified under the heading of projectile motion and are controlled by physical laws Once the performer or projectile is in the air only two external forces act upon it The first is that due to gravity and the second is air resistance The latter force is very important in such sports as ski jumping and skydiving because the velocity is quite high and the ight time relatively long It is also of special significance in the javelin and discus events because of the aerodynamic characteristics of these implements However in many activities involving projectile motion air resistance plays an insignificant role Because of this fact and the desire to simplify the following laboratory experiment the force due to air resistance will be considered negligible that is equal to zero In this lab you will be calculating your vertical jump height and broad jump distance using various methods By what formulas is projectile motion represented W Horizontal Motion Yf Yi t ViAt lZaAt2 Xf Xi Vim VfViaAt VIC V02 Viz t 23yr Yr Vf2 Viz ag981ms2 a0 where Vf final velocity in msec vi initial velocity in msec a acceleration in msec2 t time in seconds Xf yf final position in meters xi y initial position in meters In a simple problem a ball is thrown through the air Given sufficient information concerning the conditions at the instant of release and making certain assumptions we can calculate variables describing the motion of the projectile while in ight at one second in time V 0 Vertical Vertical displacement Displacement velocity Velocity rbuEDdeSVdoc 1 071610 When the ball is in the air gravity and air are the forces acting on the ball We usually only consider gravity Vertical acceleration 981ms2 The horizontal acceleration is assumed to be zero because air 1s A J to be Example Given A ball is thrown from 25 m above ground with a resultant velocity of 65 ms at 6020 with respect to the right horizontal wrtrh vri 65 ms vv 65ms sin 602O 564 ms VVf 0 at peak a 981ms2 Find How long does it take to get the highest point on its path Picture Vv0 65 ms 6020 wrtrh 25 m Formulas VVf VVi at W VVi at VVf Vvia t Units appropriate Solution t VVf vVi a 0 564ms 981ms2 057s Find How high up from the ground does the ball get yi 25 VVi 564 va 0 t 057s a 981ms2 Units appropriate Formulas yf yi W At l2aAt2 Solution yf 25m 564ms 057s l2981ms2 057s 2 yf 732m Laboratory Emerience Procedure In this lab you will be analyzing data collected during vertical and horizontal jump trials rbuEDde5Vdoc 2 071610 Data Counter Movement Jump 1 Participant s height with arms overhead hips level and feet at 2 Participant s height with arms overhead hips level and feet plantar exed 3 Participant s height with arm overhead hip hiked and feet plantar exed 4 Recorded jump height 5 Net jump height using 1 41 6 Net jump height using 2 42 7 Net jump height using 3 43 8 Time in the air Standing Long Jump High 9 Time in the air 10 Recorded displacement of jump Standing Long Jump Low 1 l 1 Time in the air 12 Recorded displacement of jump Data Analysis and Questions For all solutions please use the problem solving method 1 Counter movement jump Using time in the air 8 calculate a Vertical velocity at takeoff b Height ofjump 2 Counter movement jump Using each of the measured vertical displacements 5 6 7 calculate a Vertical velocity at takeoff b Time from takeoff to peak c Time from peak to landing d Total time in the air 3 Standing long jump Using the time in the air 9 11 and displacement measurements 10 12 calculate a Vertical velocity at takeoff b Horizontal velocity at takeoff c Resultant velocity at takeoff d Angle of takeoff e Peak height What are the advantages and disadvantages of each method used to measure jump heights 5 6 7 8 The formula used in projectile motion calculations apply to the center of mass of the object In the vertical jump was the center of mass position at takeoff the same as the center of mass position at landing What is the signi cance of this to our measurements If you wanted to maximize your vertical displacement what is the optimum angle of takeoff rbuEDdeSVdoc 071610 chapter Neural Control of Exercising Muscle Learning Objectives Learn the basic structures of the nervous system Follow the pathways of nerve impulses from initiation to muscle action Discover how neurons communicate with one another and learn the role of neurotransmitters in this communication continued Learning Objectives continued Understand the functional organization of the central nervous system Become familiar with the roles of the sensory and motor divisions of the peripheral nervous system Learn how a sensory stimulus gives rise to a motor response Consider how individual motor units respond and how they are recruited in an orderly manner depending on the required force IIIIIIIIIIIIIIIIIIIIIIIIIIII ORGANIZATION OF THE NERVOUS SYSTEM Central nervous system Pemipheral newcqu system CIELJJHQJQ UWEI VETJM 56 Irtnl m Sympathe ic Parasympatheiic STRUCTURE OF A NEURON Dendrilas N UCISOIUS Nissl bodies Axon terminal or synaptic knob Node 0 Mygun Ranviar Amquot sheath End branches Node cl Flanvler Neurilemma Myelin shealh Impulse l Action potential reaches presynaptic terminal action 1 potential Nerve Impulse An electrical charge that passes from one neuron to the next and finally to an end organ such as a group of muscle fibers 2 Depolarization of presynaptic terminal opens ion channels allowing calcium Ca2 into cell 3 Ca2 triggers release of neurotransmitter from vesicles 39L 4 Neurotransmitter binds to receptor sites on postsynaptic membrane Ca2 T Neurotransmitter is inactivated or transported back into presynaptic terminal H Y vesicle fused with membrane 3quot g 439 neurotransmitter filled vesicle postsynaptic channel receptors 5 Opening and closing of ion channels cause change in postsynaptic membrane potential action 39 1 39 potential I gt 39synaptic 1 cleft 6 Action potential propagates through next cell E 2002 Encyclopaedia Britannica Inc postsynaptic membrane presynaptic terminal Resting Membrane Potential RMP Difference between the electrical charges inside and outside a cell caused by separation of charges across a membrane High concentration of K inside the neuron and Na outside the neuron K ions can move freely even outside the cell to help maintain imbalance Sodiumpotassium pump actively transports K and Na ions to maintain imbalance The constant imbalance keeps the RMP at 70mV Sodiumpotassium pump using energy from ATP produces a polarized membrane Electrogenic Na K Pump Outs IdG 39 1 mum lemming Ins de There are 3 sites for Na attachment on the inside surface of the carrier 2 sites for K on the outside surface of the carrier A39I Pase on the intracellular surface hydrolyzes ATP The energy released causes a conformational change in the carrier which pumps the 3 Naions out then K attaches and the 2 K ions are pumped in The fact that more positive ions are pumped out together with nonpermeable intracellular negative ions produces a polarized membrane Changes in Membrane Potential Depolarization occurs when inside of cell becomes less negative relative to outside gt 70 mV Hyperpolarization occurs when inside of cell becomes more negative relative to outside lt 70 mV Graded potentials are localized changes in membrane potential either depolarization or hyperpolarization Action potentials are rapid substantial depolarization of the membrane 70 mV to 30 mV to 70 mV all in 1 ms What Is an Action Potential o Starts as a graded A potential Requires dePOlarization greater than the threshold value of 15 mv to 20 mV Once threshold is met or exceeded Threshold R t39 tt the allornone es 111 S aquot principle applies 0 I Voltage 111V LII U1 Stimulus Failed eriod initiations Tune ms RESTING STATE ACTION POTENTIAL NT Na l K T v K 30mV Action of the NaK pump Increased Na permeability and depolarization K quotT W 70 VK 39 quot J l l Repolarization Propagation of an action potential Events During an Action Potential Resting state Depolarization Propagation of l a n n membrane Jotentlal potential ll Repolarization Return to the resting state f 4 KE with the help of m 39 51 threshold potential to action potential i 9 repolarization 0 7 thesodlum L t H g 39m 90090 a H0 o gyouv uoou po aSSIUm pump u n n m mu m m m l ul m n 39 39 U a 4 g o 0 a u g membrane permeability open channels per square millimetre N D membrane potential millivolts I p D K permeance 5 t u n D U Q Q are 4 H o o a quotL Davy u Q U L1 U U Q a u o a 0 u 0 e u o 2002 E n cycle paedia Britan nica Inc The Velocity of an Action Potential Myelinated fibers Saltatory conduction potential travels quickly from one break in myelin to the next Action potential is slower in unmyelinated fibers than in myelinated fibers Diameter of the neuron Largerdiameter neurons conduct nerve impulses faster Largerdiameter neurons present less resistance to current flow Key Points The Nerve Impulse A neuron s RMP of 70 mV is maintained by the sodiumpotassium pump Changes in membrane potential occur when ion gates in the membrane open permitting ions to move from one side to the other Ifthe membrane potential depolarizes by 15 mV to 20 mV the threshold is reached resulting in an action potential continued Key Points continued The Nerve Impulse lmpulses travel faster in myelinated axons and in neurons with larger diameters Saltatory conduction refers to an impulse traveling along a myelinated fiber by jumping from one node of Ranvier to the next The Synapse A synapse is the site of an impulse transmission between two neurons An impulse travels to a presynaptic axon terminal where it causes synaptic vesicles on the terminal to release chemicals into the synaptic cleft Chemicals are picked up by postsynaptic receptors on an adjacent neuron A Chemical Synapse Axon terminal x of presynaptic neuron Synaptic vesicle Synaptic cleft The Neuromuscular Junction The junction is a site where a motor neuron communicates with a muscle fiber Axon terminal releases neurotransmitters such as acetylcholine or epinephrine which travel across a synaptic cleft and bind to receptors on a muscle fiber This binding causes depolarization possibly causing an action potential The action potential spreads across the sarcolemma causing the muscle fiber to contract The Neuromuscular Junction Synaptic Vesicles mMotor neuron ber 8 t39 ft Nerve fiber ynap cce branches Motor end plate Myofibrll of muscle fiber Neurotransmitters 04quot Refractory Period Period of repolarization The muscle fiber is unable to respond to any further stimulation The refractory period limits a motor unit s firing frequency Key Points Synapses Neurons communicate with one another by releasing neurotransmitters across synapses Synapses involve a presynaptic axon terminal a postsynaptic receptor neurotransmitters and the space between them Neurotransmitters bind to the receptors and cause depolarization excitation or hyperpolarization inhibition depending on the specific neurotransmitter and the site to which it binds continued Key Points continued Neuromuscular Junctions Neurons communicate with muscle cells at neuromuscularjunctions which function much like a neural synapse The refractory period is the time it takes the muscle fiber to repolarize before the fiber can respond to another stimulus Acetylcholine and epinephrine are the neurotransmitters most important in regulating exercise continued Key Points continued The Postsynaptic Response Binding of a neurotransmitter causes a graded action potential in the postsynaptic membrane An excitatory impulse causes hyperpolarization or depolarization An inhibitory impulse causes hyperpolarization The axon hillock keeps a running total of the neuron s responses to incoming impulses A summation of impulses is necessary to generate an action potential Central Nervous System Brain Cerebrum is the site of the mind and intellect Diencephalon is the site of sensory integration and regulation of homeostasis Cerebellum plays a crucial role in coordinating movement Brain stem connects brain to spinal cord contains regulators of respiratory and cardiovascular systems Peripheral Nervous System Spinal Cord 12 cranial nerves connected with the brain 31 spinal nerves connected with the spinal cord Sensory division carries sensory info from body via afferent fibers to the CNS Motor division transmits information from CNS via afferent fibers to target organs Autonomic nervous system controls involuntary internal functions Four Major Regions of the Brain and Four Outer Lobes of the Cerebrum Frontal Parietal lobe lobe Cerebrum Occip ital Diencephalon Cerebellum Temporal Mldbraln l Brain stem ll l Pons Medulla oblongata Sensory and Motor Homunculus 3E 53 J H gr bl Motor Cortex vn right canme mn nspherr it Somamssmsory cwmx In rzghi EHrehral hemlsghena The Nervous Systems P 39r i phzeral mermus system Types of Sensory Receptors Mechanoreceptors respond to mechanical forces such as pressure touch vibrations and stretch Thermoreceptors respond to changes in temperature Nociceptors respond to painful stimuli Photoreceptors respond to light to allow vision Chemoreceptors respond to chemical stimuli from foods odors and changes in blood concentrations Muscle and Joint Nerve Endings Joint kinesthetic receptors in joint capsules sense the position and movement ofjoints Muscle spindles sense how much a muscle is stretched Golgi tendon organs detect the tension of a muscle on its tendon providing information about the strength of muscle contraction Sympathetic Nervous System Fightorflight prepares you for acute stress or physical activity It facilitates your motor response with increases in heart rate and strength of heart contraction blood supply to the heart and active muscles metabolic rate and release of glucose by the liver blood pressure rate of gas exchange between lungs and blood and mental activity and quickness of response Parasympathetic Nervous System Housekeeping digestion urination glandular secretion and energy conservation Actions oppose those of the sympathetic system Decreases heart rate Constricts coronary vessels Constricts tissues in the lungs Key Points Peripheral Nervous System The peripheral nervous system contains 43 pairs of nerves and is divided into sensory and motor divisions The sensory division carries information from the sensory receptors to the CNS The motor division includes the autonomic nervous system The motor division carries impulses from the CNS to the muscles or target organs continued Key Points continued Peripheral Nervous System The autonomic nervous system includes the sympathetic and parasympathetic nervous systems The sympathetic nervous system prepares the body for an acute response The parasympathetic nervous system carries out processes such as digestion and urination The sympathetic and parasympathetic systems are opposing systems that function together Integration Centers Spinal cord controls simple motor reflexes such as pulling your hand away after touching something hot Lower brain stem controls more complex subconscious motor reactions such as postural control Cerebellum governs subconscious control of movement such as that needed to coordinate multiple movements Thalamus governs conscious distinction among sensations such as feeling hot and cold Cerebral cortex maintains conscious awareness of a signal and the location of the signal within the body SENSORYMOTOR INTEGRATION a A stimulus to the skin is received I a sensory receptor I b The impulse travels through sensory neurons to the CNS Sensory receptor c The CNS interprets the information and determines the motor response Sensory neuron e The motor impulse reaches the muscle fibers and the response ODCLH S Motor neuron I dThe motor impulse lravels out from the CNS through motor neurons SENSORY RECEPTORS AND PATHWAYS Motor cortex Sensory CO rlex Thalamus Cerebellum Reticular iormation Kinesthetic receptor Skin Free nerve ending pain temperature Meissner s corpuscle touch Pacinian corpuscle pressure Golgi tendon orgain Muscle spindle MOTOR PATHWAYS M otor area Motor Control Sensory impulses evoke a response through a motor neuron The closer to the brain the impulse stops the more complex the motor reaction A motor reflex is a preprogrammed response that is integrated by the spinal cord without conscious thought Muscle Spindles Lie between and are connected to regular skeletal muscle fibers The middle of the spindle cannot contract but can stretch When muscles attached to the spindle are stretched neurons on the spindle transmit information to the CNS about the muscle s length Reflexive muscle contraction is triggered to resist further stretching Aliment Flower spray Ending Annulospiral endings Nuclear Chaim fiber NUC39BEF bag ber Capsule Mater and plate muscle spindle a mechanorece muscle the muscle spindles are arranged in parallel with muscle bers They respond to passive stretch of the muscle but cease to discharge if the muscle contracts isotonically thus signaling muscle length The muscle spindle is the rece tor res onsible for the stretch or m otatic re ex Golgi Tendon Organs GTOs Encapsulated sensory organs through which muscle tendon fibers pass Located close to the tendon s quot m es m39w39gamx attachment to the muscle 39 Sense small changes in tension Inhibit contracting agonist muscles and excite antagonist eolgitendonorgans K muscles to prevent injury MUSCLE BODY MUSCLE SPINDLE AND GTO l neurons from CNS Sensory neurons tl llli p quot9 Vl1i v r 1 Central region Gamma molor neurons from CNS lacks myofibrils Muscle spindle Extrafusal muscle fibers Extran sal muscle fibers Afferent neuron Capsule Collagen fiber Sensory neuron Golgi tendon organ Tendon Tendon Conscious Control of Movement Neurons in the primary motor cortex control voluntary muscle movement Clusters of nerve cells in the basal ganglia initiate sustained and repetitive movements walking running maintaining posture and muscle tone The cerebellum controls fast and complex muscular activity Key Points SensoryMotor Integration Sensorymotor integration is the process by which the PNS relays sensory input to the CNS which processes the input and response with the appropriate motor signal Sensory input may be integrated at the spinal cord in the brain stem or in the brain depending on its complexity Reflexes are automatic responses to a given stimulus continued Key Points continued SensoryMotor Integration Muscle spindles and Golgi tendon organs trigger reflexes to protect the muscles from being overstretched The primary motor cortex basal ganglia and cerebellum all integrate sensory input for voluntary muscle action Engrams are memorized motor patterns stored in the brain Did You Know Muscles controlling fine movements such as those controlling the eyes have a small number of muscle fibers per motor neuron about 1 neuron for every 15 muscle fibers Muscles with more general function such as those controlling the calf muscle in the leg have many fibers per motor neuron about 1 neuron for every 2000 muscle fibers