© 2007 McGraw-Hill Higher Education. All rights reserved Chapter 13 Muscular Analysis of Trunk and Lower Extremity Exercises Manual of Structural Kinesiology R.T. Floyd, EdD, ATC, CSCS

© 2007 McGraw-Hill Higher Education. All rights reserved Muscular Analysis of Trunk & Lower Extremity Exercises Strength, endurance, & flexibility of the lower extremity, trunk, & abdominal muscles are very important in skillful physical performance & body maintenanceStrength, endurance, & flexibility of the lower extremity, trunk, & abdominal muscles are very important in skillful physical performance & body maintenance Whether the muscle is lengthening or shortening during movement determines contraction typeWhether the muscle is lengthening or shortening during movement determines contraction type –Muscles may shorten or lengthen in the absence of a contraction through passive movement caused by other contracting muscles, momentum, gravity, or external forces such as manual assistance machines

© 2007 McGraw-Hill Higher Education. All rights reserved Muscular Analysis of Trunk & Lower Extremity Exercises Concentric contractionsConcentric contractions –shortening contraction of muscles against gravity or resistance Eccentric contractionEccentric contraction –muscle lengthens under tension to control the joints moving with gravity or resistance

© 2007 McGraw-Hill Higher Education. All rights reserved Muscular Analysis of Trunk & Lower Extremity Exercises Quadriceps contracts eccentrically when the body slowly lowers in a weight- bearing movement through lower extremity actionQuadriceps contracts eccentrically when the body slowly lowers in a weight- bearing movement through lower extremity action –functions as a decelerator to knee joint flexion in weight-bearing movements by contracting eccentrically to prevent too rapid of a downward movement slow descent is eccentric & ascent from the squatted position is concentricslow descent is eccentric & ascent from the squatted position is concentric

© 2007 McGraw-Hill Higher Education. All rights reserved Muscular Analysis of Trunk & Lower Extremity Exercises Quadriceps function in squattingQuadriceps function in squatting –descent at the same speed as gravity, essentially under no muscular control, the muscle lengthening would be passive movement & change in muscle length would be caused by gravity, not by active muscular contractionmovement & change in muscle length would be caused by gravity, not by active muscular contraction

© 2007 McGraw-Hill Higher Education. All rights reserved Free Weight-Training Exercises Exercise with weights is a commonly used means of developing & maintaining muscular strength in young people & adultsExercise with weights is a commonly used means of developing & maintaining muscular strength in young people & adults When using free weights it is important to ensure that one group of muscles is not overdeveloped and another is underdevelopedWhen using free weights it is important to ensure that one group of muscles is not overdeveloped and another is underdeveloped –Thorough knowledge of muscles being used is essential

© 2007 McGraw-Hill Higher Education. All rights reserved Sit-up, bent knee Participant lies on back, forearms crossed and lying across chest, with knees flexed 90 degrees & feet about hip-width apartParticipant lies on back, forearms crossed and lying across chest, with knees flexed 90 degrees & feet about hip-width apart Hips & knees are flexed in this manner to reduce hip flexor length, thereby reducing their contribution to sit-up & allow more emphasis on abdominalsHips & knees are flexed in this manner to reduce hip flexor length, thereby reducing their contribution to sit-up & allow more emphasis on abdominals Participant curls up to a sitting position, rotates trunk to right, touches left elbow to right kneeParticipant curls up to a sitting position, rotates trunk to right, touches left elbow to right knee Returns to starting positionReturns to starting position Rotate to left on next repetitionRotate to left on next repetition

© 2007 McGraw-Hill Higher Education. All rights reserved Sit-up, bent knee Joint Curling phase to sitting-up position Rotating to right phase ActionAgonistsActionAgonists Cervical spine Flexion Cervical spine flexors Sternocleidomastoid Maintenance of cervical flexion Cervical spine flexors (isometric contraction) Sternocleidomastoid TrunkFlexion Trunk flexors Rectus abdominis External oblique abdominal Internal oblique abdominal Right lumbar rotation Right lumbar rotators R) Rectus abdominis L) External oblique abdominal R) Internal oblique abdominal R) Erector spinae HipFlexion Hip flexors Iliopsoas Rectus femoris Pectineus Maintenance of hip flexion Hip flexors (isometric contraction) Iliopsoas Rectus femoris Pectineus

© 2007 McGraw-Hill Higher Education. All rights reserved Sit-up, bent knee Joint Return phase to sitting-up position Return phase to starting position ActionAgonistsActionAgonists Cervical spine Maintenance of cervical flexion Cervical spine flexors (isometric contraction) SternocleidomastoidExtension Cervical spine flexors (eccentric contraction) Sternocleidomastoid Trunk Left lumbar rotation to neutral position Right lumbar rotators (eccentric contraction) R) Rectus abdominis L) External oblique abdominal R) Internal oblique abdominal R) Erector spinae Extension Trunk flexors (eccentric contraction) Rectus abdominis External oblique abdominal Internal oblique abdominal Hip Maintenance of hip flexion Hip flexors Iliopsoas Rectus femoris PectineusExtension Hip flexors (eccentric contraction) Iliopsoas Rectus femoris Pectineus

© 2007 McGraw-Hill Higher Education. All rights reserved Alternating Prone Extensions Participant lies prone position, with the shoulders fully flexed in a relaxed position lying in front of the bodyParticipant lies prone position, with the shoulders fully flexed in a relaxed position lying in front of the body Participant raises head, upper trunk, & thighs from the floorParticipant raises head, upper trunk, & thighs from the floor Knees are kept in full extensionKnees are kept in full extension Then return to starting positionThen return to starting position

© 2007 McGraw-Hill Higher Education. All rights reserved Alternating Prone Extensions JointAction Agonists in Lifting Action Agonists in Lowering ShoulderFlexion Shoulder joint flexors Pectoralis major (clavicular head or upper fibers) DeltoidCoracobrachialis Biceps brachii Extension Shoulder joint flexors (eccentric contraction) Pectoralis major (clavicular head or upper fibers) DeltoidCoracobrachialis Biceps brachii Shoulder girdle Adduction Shoulder girdle adductors TrapeziusRhomboidsAbduction Shoulder girdle adductors (eccentric contraction) TrapeziusRhomboids TrunkExtension Trunk extensors Erector spinae Splenius Quadratus lumborum Flexion (return to neutral relaxed position) Trunk & cervical spine extensors (eccentric contraction) Erector spinae Splenius Quadratus lumborum HipExtension Hip extensors Gluteus maximus SemitendinosusSemimembranosus Biceps femoris Flexion (return to neutral relaxed position) Hip extensors (eccentric contraction) Gluteus maximus SemitendinosusSemimembranosus Biceps femoris

© 2007 McGraw-Hill Higher Education. All rights reserved Squat Participant places a barbell on the shoulders behind the neck and grasps it with palms- forward position of handsParticipant places a barbell on the shoulders behind the neck and grasps it with palms- forward position of hands Participant squats down until thighs are parallel to floor, keeping back straightParticipant squats down until thighs are parallel to floor, keeping back straight Return to starting positionReturn to starting position Ensure that the shins remain as verticalEnsure that the shins remain as vertical

© 2007 McGraw-Hill Higher Education. All rights reserved Squat JointAction Agonists in Lowering Action Agonists in Lifting HipFlexion Hip extensors (eccentric contraction) Gluteus maximus SemimembranosusSemitendinosus Biceps femoris Extension Hip extensors Gluteus maximus SemimembranosusSemitendinosus Biceps femoris KneeFlexion Knee extensors (eccentric contraction) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis Extension Knee extensors Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis AnkleDorsiflexion Plantar flexors (eccentric contraction) GastrocnemiusSoleus Plantar flexion Plantar flexors GastrocnemiusSoleus

© 2007 McGraw-Hill Higher Education. All rights reserved Dead Lift Participant begins in hip flexed position, keeping arms, legs, & back straight, and grasps the barbell on the floorParticipant begins in hip flexed position, keeping arms, legs, & back straight, and grasps the barbell on the floor Move to standing position is made by extending the hipsMove to standing position is made by extending the hips Lumbar extensors must be utilized as isometric stabilizers of the low back while the hip extensors perform the majority of the lift in this exerciseLumbar extensors must be utilized as isometric stabilizers of the low back while the hip extensors perform the majority of the lift in this exercise

© 2007 McGraw-Hill Higher Education. All rights reserved Dead Lift JointAction Agonists in Lifting Wrist & hand Flexion Wrist & hand flexors (isometric contraction) Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus Trunk Maintenance of extension Trunk extensors (isometric contraction) Erector spinae (sacrospinalis) Quadratus lumborum HipExtension Hip extensors Gluteus maximus SemimembranosusSemitendinosus Biceps femoris KneeExtension Knee extensors (quadriceps) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis

© 2007 McGraw-Hill Higher Education. All rights reserved Dead Lift JointAction Agonists in Lowering Wrist & hand Flexion Wrist & hand flexors (isometric contraction) Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus Trunk Maintenance of extension Trunk extensors (isometric contraction) Erector spinae (sacrospinalis) Quadratus lumborum HipFlexion Hip extensors (eccentric contraction) Gluteus maximus SemimembranosusSemitendinosus Biceps femoris KneeFlexion Knee extensors (quadriceps) (eccentric contraction) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis

© 2007 McGraw-Hill Higher Education. All rights reserved Isometric Exercises An exercise technique in which there is contraction of muscle groups with no appreciable muscle shorteningAn exercise technique in which there is contraction of muscle groups with no appreciable muscle shortening –not as productive in terms of overall strength gains as isotonics –an effective way to build & maintain muscular strength in a limited range of motion Contractions should be held approximately seconds for a training effectContractions should be held approximately seconds for a training effect

© 2007 McGraw-Hill Higher Education. All rights reserved Abdominal Contraction Participant contracts anterior abdominal region muscles as strongly as possible without moving the trunk or hipsParticipant contracts anterior abdominal region muscles as strongly as possible without moving the trunk or hips –Rectus abdominis –External oblique abdominal –Internal oblique abdominal –Transversus abdominis

© 2007 McGraw-Hill Higher Education. All rights reserved Leg Lifter Participant sits on a bench or chair with the knees slightly bent & with left leg over rightParticipant sits on a bench or chair with the knees slightly bent & with left leg over right Attempt to raise right leg while resisting it with left legAttempt to raise right leg while resisting it with left leg

© 2007 McGraw-Hill Higher Education. All rights reserved Leg Lifter JointAction Agonists in Right – Attempting Upward Action Agonists in Left – Resisting Upward AnkleDorsiflexion Ankle dorsiflexors Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius Plantar Flexion Plantar flexors GastrocenemiusSoleus KneeExtension Knee extensors (quadriceps) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis Flexion Knee flexors (hamstrings) Biceps femoris SemitendinosusSemimbranosus HipFlexion Hip flexors Iliopsoas Rectus femoris PectineusSartorius Tensor fasciae latae Extension Hip extensors Gluteus maximus Biceps femoris SemitendinosusSemimbranosus

© 2007 McGraw-Hill Higher Education. All rights reserved Hip Sled Participant lies supine with the knees & hips flexed in a position close to chestParticipant lies supine with the knees & hips flexed in a position close to chest Feet are placed on the apparatus plateFeet are placed on the apparatus plate Knees & hips are extended completely to move the plate upwardKnees & hips are extended completely to move the plate upward Return to the starting positionReturn to the starting position

© 2007 McGraw-Hill Higher Education. All rights reserved Hip Sled JointAction Agonists in Pushing Action Agonists in Lowering Ankle Plantar flexion Ankle plantar flexors GastrocnemiusSoleusDorsiflexion Ankle plantar flexors (eccentric contraction) GastrocnemiusSoleus KneeExtension Knee extensors (quadriceps) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis Flexion Knee extensors (quadriceps) (eccentric contraction) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis HipExtension Hip extensors Biceps femoris SemimembranosusSemitendinosus Gluteus maximus Flexion Hip extensors (eccentric contraction) Biceps femoris SemimembranosusSemitendinosus Gluteus maximus

© 2007 McGraw-Hill Higher Education. All rights reserved Rowing Exercise Participant sits on a movable seat with knees & hips flexed close to the chestParticipant sits on a movable seat with knees & hips flexed close to the chest Arms are reaching forward to grasp a horizontal barArms are reaching forward to grasp a horizontal bar Legs are extended forcibly as arms are pulled toward chestLegs are extended forcibly as arms are pulled toward chest Return to starting positionReturn to starting position

© 2007 McGraw-Hill Higher Education. All rights reserved Rowing Exercise JointAction Agonists in arm pull/leg push Action Agonists in return to starting Foot & ankle Plantar flexion Ankle plantarflexors GastrocnemiusSoleusDorsiflexion Ankle dorsiflexors Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius KneeExtension Quadriceps (knee extensors) Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis Flexion Knee flexors (hamstrings) Biceps femoris SemitendinosusSemimembranosus HipExtension Hip extensors Gluteus maximus Biceps femoris SemimembranosusSemitendinosusFlexion Hip flexors Iliopsoas Rectus femoris Pectineus TrunkExtension Trunk extensors Erector spinae Flexion Trunk flexors Rectus abdominis Internal oblique abdominal External oblique abdominal

© 2007 McGraw-Hill Higher Education. All rights reserved Rowing Exercise JointAction Agonists in arm pull/leg push Action Agonists in return to starting Shoulder girdle Adduction, downward rotation, & depression Shoulder girdle adductors, downward rotators, & depressors Trapezius (lower) Rhomboid Pectoralis minor Abduction, upward rotation, & elevation Shoulder girdle adductors, downward rotators, & depressors (eccentric contraction) Trapezius (lower) Rhomboid Pectoralis minor Shoulder joint Extension Shoulder joint extensors Latissimus dorsi Teres major Posterior deltoid Teres minor InfraspinatusFlexion Shoulder joint extensors (eccentric contraction) Latissimus dorsi Teres major Posterior deltoid Teres minor Infraspinatus Elbow joint Flexion Elbow joint flexors Biceps brachii BrachialisBrachioradialisExtension Elbow joint flexors (eccentric contraction) Biceps brachii BrachialisBrachioradialis Wrist & hand Flexion Wrist & hand flexors (isometric contraction) Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus Flexion Wrist & hand flexors (isometric contraction) Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites American College of Sports Medicine –Scientific research, education, and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health, and quality of life Concept II –Information on the technique of rowing and the muscles used. Fitness World –The information at this site is about fitness in general and includes access to Fitness Management magazine.

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites National Council of Strength & Fitness –Personal Training Certification & Continuing Education for the Fitness Professional National Strength and Conditioning Association –Information on the profession of strength and conditioning specialists and personal trainers NSCA Certification Commission –The certifying body for the National Strength and Conditioning Association Presidents Council on Physical Fitness and Sports –Information and links from the U.S. government on fitness

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites ExRx.net –A resource for the exercise professional, coach, or fitness enthusiast consisting of over 1500 pages of exercises and anatomy illustrations National Academy of Sports Medicine –Offers specific certifications for health and fitness exercise specialists and a valuable resource for continuing education on exercise techniques, etc. Upper Extremity Conditioning Program –Shows strengthening exercises for the upper body

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites Rehab Team Site: Passive Stretching –Passive Range of Motion Exercises Body Map –Describes specific injuries and how to properly rehab with weights Physician and Sports Medicine: Weight Training Injuries –Article that is about upper body injuries and how to strengthen the upper body

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites NISMAT Exercise Programs –Step by step instructions of strengthening exercises along with diagrams Spine Health.com –Information on the spine including core body strengthening exercises #1 Back Pain Site –Information on back pain as well as strengthening and stretching exercises for the back

© 2007 McGraw-Hill Higher Education. All rights reserved Web Sites Runner Girl.com –Strengthening and stretching exercises as well as other health and fitness information for women