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 maintenance
Chapter 13
Muscular Analysis of Trunk and
Lower Extremity Exercises
• Whether 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
Manual of Structural Kinesiology
R.T. Floyd, EdD, ATC, CSCS
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-1
Muscular Analysis of Trunk & Lower
Extremity Exercises
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-2
Muscular Analysis of Trunk & Lower
Extremity Exercises
• Quadriceps contracts eccentrically when
• Concentric contractions
the body slowly lowers in a weight-
– shortening contraction of muscles against
bearing movement through lower
gravity or resistance
extremity action
• Eccentric contraction
– functions as a decelerator to knee joint
– muscle lengthens under tension to control
flexion in weight-bearing movements by
the joints moving with gravity or resistance
contracting eccentrically to prevent too rapid
of a downward movement
• slow descent is eccentric & ascent from the
squatted position is concentric
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-3
Muscular Analysis of Trunk & Lower
Extremity Exercises
13-4
Free Weight-Training Exercises
• Exercise 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 underdeveloped
• Quadriceps 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
contraction
© 2007 McGraw-Hill Higher Education. All rights reserved.
© 2007 McGraw-Hill Higher Education. All rights reserved.
– Thorough knowledge of muscles being used is
essential
13-5
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-6
1
Sit-up, bent knee
Sit-up, bent knee
Curling phase to sitting-up position
• Participant 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 abdominals
• Participant curls up to a sitting position,
rotates trunk to right, touches left elbow to
right knee
• Returns to starting position
• Rotate to left on next repetition
Joint
13-7
Sit-up, bent knee
Joint
Action
Agonists
Hip
Left lumbar
rotation to
neutral
position
Extension
R) Rectus abdominis
L) External oblique
abdominal
R) Internal oblique
abdominal
R) Erector spinae
Maintenance Hip flexors
of hip flexion Iliopsoas
Rectus femoris
Pectineus
Agonists
Cervical spine flexors
(eccentric contraction)
Sternocleidomastoid
Trunk flexors (eccentric
contraction)
Rectus abdominis
External oblique
abdominal
Internal oblique
abdominal
Trunk
Flexion Trunk flexors
Rectus abdominis
External oblique
abdominal
Internal oblique
abdominal
Right lumbar Right lumbar rotators
rotation
R) Rectus abdominis
L) External oblique
abdominal
R) Internal oblique
abdominal
R) Erector spinae
Hip
Flexion Hip flexors
Iliopsoas
Rectus femoris
Pectineus
Maintenance Hip flexors (isometric
of hip flexion contraction)
Iliopsoas
Rectus femoris
13-8
Pectineus
© 2007 McGraw-Hill Higher Education. All rights reserved.
• Participant 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 floor
• Knees are kept in full
extension
Extension
Hip flexors (eccentric
contraction)
Iliopsoas
Rectus femoris
Pectineus
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-9
• Then return to starting position
Action
Shoulder Flexion
Agonists in Lifting
Shoulder joint flexors
Action
Extension
Pectoralis major
(clavicular head or upper
fibers)
Deltoid
Coracobrachialis
Biceps brachii
Shoulder Adduction
girdle
Shoulder girdle adductors
Trunk
Trunk extensors
Extension
Trapezius
Rhomboids
Erector spinae
Splenius
Quadratus lumborum
Hip
Extension
Hip extensors
Gluteus maximus
Semitendinosus
Semimembranosus
© 2007 McGraw-Hill Higher Education. All rights reserved.
Biceps femoris
Squat
Agonists in Lowering
Shoulder joint flexors (eccentric
contraction)
Pectoralis major (clavicular head
or upper fibers)
Deltoid
Coracobrachialis
Biceps brachii
Abduction
13-10
© 2007 McGraw-Hill Higher Education. All rights reserved.
Alternating Prone Extensions
Joint
Agonists
Maintenance Cervical spine flexors
(isometric contraction)
of cervical
Sternocleidomastoid
flexion
Alternating Prone Extensions
Action
Right lumbar rotators
(eccentric contraction)
Action
Return phase to starting position
Cervical Maintenance Cervical spine flexors
Extension
(isometric contraction)
spine
of cervical
Sternocleidomastoid
flexion
Trunk
Rotating to right phase
Agonists
Cervical Flexion Cervical spine flexors
spine
Sternocleidomastoid
© 2007 McGraw-Hill Higher Education. All rights reserved.
Return phase to sitting-up position
Action
Shoulder girdle adductors (eccentric
contraction)
Trapezius
Rhomboids
the shoulders behind the neck
and grasps it with palmsforward position of hands
• Participant squats down until
thighs are parallel to floor,
keeping back straight
Flexion
(return to
neutral
relaxed
position)
Trunk & cervical spine extensors
(eccentric contraction)
Flexion
(return to
neutral
relaxed
position)
Hip extensors (eccentric contraction)
• Return to starting position
Erector spinae
Splenius
Quadratus lumborum
Gluteus maximus
Semitendinosus
Semimembranosus
Biceps femoris
• Participant places a barbell on
• Ensure that the shins remain
13-11
as vertical
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-12
2
Squat
Joint
Hip
Action
Flexion
Knee Flexion
Dead Lift
Agonists in Lowering
Action
Agonists in Lifting
Hip extensors (eccentric Extension
contraction)
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Hip extensors
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Knee extensors
(eccentric contraction)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Knee extensors
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Ankle Dorsiflexion Plantar flexors
(eccentric contraction)
Gastrocnemius
© 2007 McGraw-Hill Higher Education. All rights
reserved.
Soleus
Extension
Plantar
flexion
• Participant 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 hips
• Lumbar extensors must be
utilized as isometric stabilizers
of the low back while the hip
extensors perform the majority
Plantar flexors
Gastrocnemius
Soleus
of the lift in this exercise
13-13
Dead Lift
Joint
Action
Dead Lift
Agonists in Lifting
Joint
Wrist & hand flexors (isometric contraction)
Wrist & hand Flexion
13-14
© 2007 McGraw-Hill Higher Education. All rights reserved.
Wrist & hand
Action
Flexion
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Flexor digitorum profundus
Flexor digitorum superficialis
Flexor pollicis longus
Trunk
Hip
Maintenance of
extension
Trunk extensors (isometric contraction)
Extension
Hip extensors
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Flexor digitorum profundus
Flexor digitorum superficialis
Flexor pollicis longus
Trunk
Erector spinae (sacrospinalis)
Quadratus lumborum
Hip
Maintenance of
extension
Trunk extensors (isometric contraction)
Flexion
Hip extensors (eccentric contraction)
Knee
Knee extensors (quadriceps)
Extension
© 2007 McGraw-Hill Higher Education. All rights reserved.
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
13-15
Isometric Exercises
Flexion
© 2007 McGraw-Hill Higher Education. All rights reserved.
Knee extensors (quadriceps) (eccentric contraction)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
13-16
Abdominal Contraction
• An exercise technique in which there is
• Participant contracts
contraction of muscle groups with no
anterior abdominal region
appreciable muscle shortening
muscles as strongly as
possible without moving
– not as productive in terms of overall
strength gains as isotonics
the trunk or hips
– an effective way to build & maintain
– Rectus abdominis
muscular strength in a limited range of
– External oblique abdominal
motion
– Internal oblique abdominal
• Contractions should be held approximately 7-
– Transversus abdominis
10 seconds for a training effect
© 2007 McGraw-Hill Higher Education. All rights reserved.
Erector spinae (sacrospinalis)
Quadratus lumborum
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Knee
Agonists in Lowering
Wrist & hand flexors (isometric contraction)
13-17
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-18
3
Leg Lifter
Leg Lifter
Joint
• Participant sits on a
bench or chair with
the knees slightly
bent & with left leg
Action
Plantar flexors
Gastrocenemius
Soleus
Knee Extension
Flexion
Knee flexors (hamstrings)
Biceps femoris
Semitendinosus
Semimbranosus
right leg while
Hip
13-19
© 2007 McGraw-Hill Higher Education. All rights reserved.
Knee extensors
(quadriceps)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Flexion
Hip flexors
Iliopsoas
Rectus femoris
Pectineus
Sartorius
© 2007 McGraw-Hill Higher Education. All rights reserved.
Tensor fasciae latae
Extension Hip extensors
Gluteus maximus
Biceps femoris
Semitendinosus
Semimbranosus
13-20
Hip Sled
Hip Sled
Joint
Action
Ankle Plantar
flexion
• Participant lies supine with the
knees & hips flexed in a
position close to chest
• Feet are placed on the
apparatus plate
• Knees & hips are extended
Agonists in Pushing
Action
upward
Knee Extension 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
Hip
Flexion
Hip extensors (eccentric
contraction)
Biceps femoris
Semimembranosus
Semitendinosus
13-22
Gluteus maximus
• Return to the starting position
13-21
Agonists in Lowering
Ankle plantar flexors Dorsiflexion Ankle plantar flexors
(eccentric contraction)
Gastrocnemius
Gastrocnemius
Soleus
Soleus
completely to move the plate
© 2007 McGraw-Hill Higher Education. All rights reserved.
Agonists in Left – Resisting
Upward
Plantar
Flexion
• Attempt to raise
leg
Action
Ankle Dorsiflexion Ankle dorsiflexors
Tibialis anterior
Extensor hallucis longus
Extensor digitorum
longus
Peroneus tertius
over right
resisting it with left
Agonists in Right –
Attempting Upward
Extension Hip extensors
Biceps femoris
Semimembranosus
Semitendinosus
Gluteus maximus
© 2007 McGraw-Hill Higher Education. All rights reserved.
Rowing Exercise
Rowing Exercise
Joint
Action
Foot Plantar
&
flexion
ankle
• Participant sits on a movable
Agonists in arm pull/leg push
Ankle plantarflexors
Gastrocnemius
Soleus
seat with knees & hips flexed
close to the chest
• Arms are reaching forward to
grasp a horizontal bar
• Legs are extended forcibly as
arms are pulled toward chest
• Return to starting position
13-23
Agonists in return to starting
Knee Extension Quadriceps (knee extensors) Flexion
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Knee flexors (hamstrings)
Biceps femoris
Semitendinosus
Semimembranosus
Hip
Flexion
Hip flexors
Iliopsoas
Rectus femoris
Pectineus
Flexion
Trunk flexors
Rectus abdominis
Internal oblique abdominal
13-24
External oblique abdominal
Extension Hip extensors
Gluteus maximus
Biceps femoris
Semimembranosus
Semitendinosus
Trunk Extension Trunk extensors
Erector spinae
© 2007 McGraw-Hill Higher Education. All rights reserved.
Action
Dorsiflexion Ankle dorsiflexors
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius
© 2007 McGraw-Hill Higher Education. All rights reserved.
4
Rowing Exercise
Joint
Action
Agonists in arm pull/leg push
Shoulder Adduction, Shoulder girdle adductors, downward
girdle
downward rotators, & depressors
rotation, & Trapezius (lower)
depression Rhomboid
Pectoralis minor
Shoulder Extension
joint
Elbow
joint
Flexion
Wrist &
hand
Flexion
Shoulder joint extensors
Action
Shoulder girdle adductors, downward
rotators, & depressors (eccentric
contraction)
Flexion
Shoulder joint extensors (eccentric
contraction)
Latissimus dorsi
Teres major
Posterior deltoid
Teres minor
Infraspinatus
Trapezius (lower)
Rhomboid
Pectoralis minor
Latissimus dorsi
Teres major
Posterior deltoid
Teres minor
Infraspinatus
Elbow joint flexors
Biceps brachii
Brachialis
Brachioradialis
Wrist & hand flexors (isometric
contraction)
Extension Elbow joint flexors (eccentric contraction)
Biceps brachii
Brachialis
Brachioradialis
Wrist & hand flexors (isometric
Flexion
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Flexor digitorum profundus
Flexor digitorum superficialis
© 2007 McGraw-Hill Higher Education. All rights reserved.
Flexor pollicis longus
Web Sites
Agonists in return to starting
Abduction,
upward
rotation, &
elevation
contraction)
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Flexor digitorum profundus
Flexor digitorum superficialis
Flexor pollicis longus
13-25
American College of Sports Medicine
www.acsm.org
– 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
http://www.concept2.com/05/training/training/gettingstarted.asp
– Information on the technique of rowing and the muscles used.
Fitness World
www.fitnessworld.com
– The information at this site is about fitness in general and
includes access to Fitness Management magazine.
Web Sites
Web Sites
National Council of Strength & Fitness
www.ncsf.org
– Personal Training Certification & Continuing Education for the
Fitness Professional
National Strength and Conditioning Association
www.nsca-lift.org
– Information on the profession of strength and conditioning
specialists and personal trainers
NSCA Certification Commission
www.nsca-cc.org
– The certifying body for the National Strength and Conditioning
Association
Presidents Council on Physical Fitness and Sports
www.fitness.gov
– Information and links from the U.S. government on fitness
ExRx.net
www.exrx.net/Lists/Directory.html
– 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
www.nasm.org
– Offers specific certifications for health and fitness exercise
specialists and a valuable resource for continuing education
on exercise techniques, etc.
Upper Extremity Conditioning Program
www.eatonhand.com/hw/nirschl.htm
– Shows strengthening exercises for the upper body
13-27
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-28
© 2007 McGraw-Hill Higher Education. All rights reserved.
Web Sites
Web Sites
Rehab Team Site: Passive Stretching
http://calder.med.miami.edu/pointis/upper.html
– Passive Range of Motion Exercises
Body Map
http://www.athleticadvisor.com/Injuries/general_injuries.htm
– Describes specific injuries and how to properly rehab with
weights
Physician and Sports Medicine: Weight Training Injuries
www.physsportsmed.com/issues/1998/03mar/laskow2.htm
– Article that is about upper body injuries and how to strengthen
the upper body
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-26
© 2007 McGraw-Hill Higher Education. All rights reserved.
NISMAT Exercise Programs
www.nismat.org/orthocor/programs/
– Step by step instructions of strengthening exercises along
with diagrams
Spine Health.com
www.spine-health.com/
– Information on the spine including core body strengthening
exercises
#1 Back Pain Site
www.1backpain.com/
– Information on back pain as well as strengthening and
stretching exercises for the back
13-29
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-30
5
Web Sites
Runner Girl.com
www.runnergirl.com
– Strengthening and stretching exercises as well as other health
and fitness information for women
© 2007 McGraw-Hill Higher Education. All rights reserved.
13-31
6
