1. Proprioceptors and the Kinesthetic Sense

2. If you are going to be successful in any performance context, you must be able to coordinate your motor performance.If you are going to be successful in any performance context, you must be able to coordinate your motor performance. In order to do this, you have to be aware of the position of the different parts of your body as well as be able to keep your balance.In order to do this, you have to be aware of the position of the different parts of your body as well as be able to keep your balance. You must have a sense of where your body is in relation to the environment and where all your various body parts are in relation to each other.You must have a sense of where your body is in relation to the environment and where all your various body parts are in relation to each other. This sense of your body is called your kinesthetic sense (a sense of yourself in motion) and it is critical for the learning and performance of perceptual-motor skills.This sense of your body is called your kinesthetic sense (a sense of yourself in motion) and it is critical for the learning and performance of perceptual-motor skills. Your kinesthetic sense relies on a system of sensory receptors called “proprioceptors.”Your kinesthetic sense relies on a system of sensory receptors called “proprioceptors.” 2

3. Structure and Function of the Proprioceptors A system of specialized receptors called proprioceptors provide your central nervous system with critical information for balance and body awareness.A system of specialized receptors called proprioceptors provide your central nervous system with critical information for balance and body awareness. These receptors are located in the muscles, tendons and joints.These receptors are located in the muscles, tendons and joints. These proprioceptors keep your brain informed about what is happening to your body.These proprioceptors keep your brain informed about what is happening to your body. Proprioceptors are mechanoreceptors because they require mechanical stimuli for activation.Proprioceptors are mechanoreceptors because they require mechanical stimuli for activation. 3

4. Muscle Spindles 4

5. The Muscle Spindles Scattered throughout all of your skeletal muscles are tiny stretch receptors, the muscle spindles.Scattered throughout all of your skeletal muscles are tiny stretch receptors, the muscle spindles. Muscle spindles provide information about muscle length.Muscle spindles provide information about muscle length. Muscle spindles lay parallel to the muscle fibers.Muscle spindles lay parallel to the muscle fibers. When a muscle is stretched, its length changes.When a muscle is stretched, its length changes. Muscle spindles activates when muscle lengthens (due to potential danger).Muscle spindles activates when muscle lengthens (due to potential danger). When muscle reaches a certain length, muscle spindles tell the nervous system to contract muscle to prevent further stretching – prevents against muscle damage.When muscle reaches a certain length, muscle spindles tell the nervous system to contract muscle to prevent further stretching – prevents against muscle damage. The more quickly the stretch/length change, the more rapid the firing of impulses.The more quickly the stretch/length change, the more rapid the firing of impulses. In this way, the muscle spindles can report on the velocity (speed) of muscle activity as well as the extent of the stretch achieved during muscle activityIn this way, the muscle spindles can report on the velocity (speed) of muscle activity as well as the extent of the stretch achieved during muscle activity When the muscle contracts, it is called the point of bind (POB).When the muscle contracts, it is called the point of bind (POB). 5

6. The Golgi Tendon Organ 6

7. The Golgi Tendon Organs Changes in tendon length and tension are detected by Golgi tendon organs.Changes in tendon length and tension are detected by Golgi tendon organs. The tension increases within a tendon as a result of muscle contraction.The tension increases within a tendon as a result of muscle contraction. The tension stimulates a Golgi tendon organ that then sends signals to the spinal cord and cerebellum to inform them about the contraction state of the muscles.The tension stimulates a Golgi tendon organ that then sends signals to the spinal cord and cerebellum to inform them about the contraction state of the muscles. As the contraction of a muscle becomes stronger, the tension becomes greater and the rate of stimulation of the tendon organ increases.As the contraction of a muscle becomes stronger, the tension becomes greater and the rate of stimulation of the tendon organ increases. In this way, the tendon organ can inform the central nervous system of the strength of muscle contraction.In this way, the tendon organ can inform the central nervous system of the strength of muscle contraction. When POB is reached, stretch is held for 10 seconds, after which the muscles relaxes and pain disappears.When POB is reached, stretch is held for 10 seconds, after which the muscles relaxes and pain disappears. Golgi Tendon Organs brings about relaxation.Golgi Tendon Organs brings about relaxation. Golgi Tendon Organs sense muscle tension, and sense when there is no danger of damage and override muscle spindles – cause muscle to relax.Golgi Tendon Organs sense muscle tension, and sense when there is no danger of damage and override muscle spindles – cause muscle to relax. 7

8. Specialized Joint Receptors Special receptors in the joints signal changes in joint position.Special receptors in the joints signal changes in joint position. This information allows you to be aware of positions of all of your various body parts.This information allows you to be aware of positions of all of your various body parts. It also informs you when there are changes in any positions.It also informs you when there are changes in any positions. These receptors are stimulated when there is movement in a joint.These receptors are stimulated when there is movement in a joint. There are three different types of joint receptors.There are three different types of joint receptors. The most common are the spray-type of Ruffini endings, similar to those found in the skin.The most common are the spray-type of Ruffini endings, similar to those found in the skin. 8

9. Specialized Joint Receptors As the joint capsule is distorted with movement, these receptors can report the rate, direction and extent of movement in a joint.As the joint capsule is distorted with movement, these receptors can report the rate, direction and extent of movement in a joint. A second type of joint receptor is similar to the Golgi tendon organ.A second type of joint receptor is similar to the Golgi tendon organ. It is located in the ligaments surrounding the joint and is stimulated by ligament stretch and tension.It is located in the ligaments surrounding the joint and is stimulated by ligament stretch and tension. A modified kind of Pacinian corpuscle is the third type of joint receptor.A modified kind of Pacinian corpuscle is the third type of joint receptor. These receptors are stimulated by pressure in connective tissue arising from the movement of the joint.These receptors are stimulated by pressure in connective tissue arising from the movement of the joint. 9

10. How Proprioceptors Work Muscle spindles are primarily involved with providing information for reflex movements,Muscle spindles are primarily involved with providing information for reflex movements, Their sensory pathway is to the spinal cord, where they can be directly associated with the command for an adjustment in movement patterns.Their sensory pathway is to the spinal cord, where they can be directly associated with the command for an adjustment in movement patterns. Because the sensory fibers from Golgi tendon organs that go to the spinal cord synapse (I ) with interneurons, communication with the thalamus and sensory cortex becomes possible.Because the sensory fibers from Golgi tendon organs that go to the spinal cord synapse (In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell) with interneurons, communication with the thalamus and sensory cortex becomes possible. 10

11. How Proprioceptors Work Joint receptors operate in teams, with one team monitoring joint movement through a 10-15 degree range, another team will take over for the next 10-15 degrees.Joint receptors operate in teams, with one team monitoring joint movement through a 10-15 degree range, another team will take over for the next 10-15 degrees. Since receptor teams are sensitive to different angles, the entire movement of that joint is covered because each team fires during their own part of the range of movement.Since receptor teams are sensitive to different angles, the entire movement of that joint is covered because each team fires during their own part of the range of movement. If movement is stopped at a certain joint angle, the receptors team responsible in that range will continue sending impulses to the central nervous system indefinitely.If movement is stopped at a certain joint angle, the receptors team responsible in that range will continue sending impulses to the central nervous system indefinitely. In addition to being able to report the angle of the joint position, receptors also are able to report the speed (velocity) of joint movement.In addition to being able to report the angle of the joint position, receptors also are able to report the speed (velocity) of joint movement. The rate at which they send impulses increases as the speed of joint movement increases.The rate at which they send impulses increases as the speed of joint movement increases. Information about joint position is sent to the cerebellum, as well as to the thalamus and on to the sensory cortex.Information about joint position is sent to the cerebellum, as well as to the thalamus and on to the sensory cortex. 11

12. PRACTICALS Practical ExamPractical Exam Four in a group.Four in a group. Each member needs to know how to catch a ball, how to bad and ball and how to field.Each member needs to know how to catch a ball, how to bad and ball and how to field. Members of the group will be rotated after 2 rounds.Members of the group will be rotated after 2 rounds. Will be held on the Veld-en-Vlei Sport Complex.Will be held on the Veld-en-Vlei Sport Complex. Date: 08/10/12 and 15/10/12Date: 08/10/12 and 15/10/12 12

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14. Proprioceptive Skills and the Kinesthetic Sense Information gathered from the proprioceptors is sent to the spinal cord, all parts of the brainstem, the cerebellum as well as the sensory cortex where it is put together to form perceptions about your body that we generally refer to as your kinesthetic sense.Information gathered from the proprioceptors is sent to the spinal cord, all parts of the brainstem, the cerebellum as well as the sensory cortex where it is put together to form perceptions about your body that we generally refer to as your kinesthetic sense. Your kinesthetic sense or your "sense of your body in motion" is a result of the information you derive from your proprioceptors.Your kinesthetic sense or your "sense of your body in motion" is a result of the information you derive from your proprioceptors. This "sense of your body as you move needs to be integrated with visual and auditory information to form a complete and accurate perception of movement situation.This "sense of your body as you move needs to be integrated with visual and auditory information to form a complete and accurate perception of movement situation. The following proprioceptive skills (kinesthetic abilities) are important for motor skill performance.The following proprioceptive skills (kinesthetic abilities) are important for motor skill performance. 14

15. 1. Body Awareness Body awareness involves your sense of the relation of your body parts to one another, and the rate at which they are moving (if they are moving).Body awareness involves your sense of the relation of your body parts to one another, and the rate at which they are moving (if they are moving). Body awareness includes your understanding of the extent of a movement pattern as you perform it.Body awareness includes your understanding of the extent of a movement pattern as you perform it. 15

16. 2. Spatial Awareness Spatial awareness is your awareness of how quickly and in what direction you are moving.Spatial awareness is your awareness of how quickly and in what direction you are moving. You could be moving forward, backward, left, right, up, down, on a rotational path, etc.You could be moving forward, backward, left, right, up, down, on a rotational path, etc. Different body parts also move in different directions and at different speed during motor skill performance.Different body parts also move in different directions and at different speed during motor skill performance. Your sense of where all the different parts of your body are in space is your spatial awareness.Your sense of where all the different parts of your body are in space is your spatial awareness. 16

17. Body Awareness Throwing the javelin Throwing the javelin provides a challenge to your body awareness, since it requires you to do a variety of different movements with your arms and legs, including a twisting of your trunk and a cross-over step. 17

18. Spatial Awareness Blocking at the net Blocking at the net in volleyball provides a challenge to your spatial awareness. You must know where you are jumping in relation to the net, get your arms fully extended, and land on your own side of the court. 18

19. Body Awareness and Spatial Awareness combine to give you a sense of where all your body parts are and how you are using the space around you In the high jump, you must have a body awareness of the relationship among your arms, legs, head and trunk, as well as a spatial awareness of moving upward and backward. 19

20. Body Awareness and Spatial Awareness combine to give you a sense of where all your body parts are and how you are using the space around you When volleying a soccer ball, you must have sufficient body awareness to create a balanced body shape in the air, and a spatial awareness of the horizontal flight of your body toward the ball 20