1. health and fitness
2. exercise

Chapter 13
Muscular Analysis of Trunk and
Lower Extremity Exercises
Manual of Structural Kinesiology
R.T. Floyd, EdD, ATC, CSCS
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-1
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
• 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
Muscular Analysis of Trunk & Lower Extremity Exercises
13-2
Muscular Analysis of Trunk & Lower
Extremity Exercises
• Concentric contractions
– shortening contraction of muscles against
gravity or resistance
• Eccentric contraction
– muscle lengthens under tension to control
the joints moving with gravity or resistance
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-3
Muscular Analysis of Trunk & Lower
Extremity Exercises
• Quadriceps contracts eccentrically when
the body slowly lowers in a weightbearing 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 concentric
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-4
Muscular Analysis of Trunk & Lower
Extremity Exercises
• 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
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-5
Conditioning Considerations
• Overload principle
– Within appropriate parameters, a muscle or muscle
group increases in strength in direct proportion to
the overload placed on it
– The amount of overload applied varies significantly
based on several factors
• An untrained person beginning a strength
training program will make significant gains in
the amount of weight he/she is able to lift in the
first few weeks
• Mostly due to a refinement of neuromuscular
function, rather than an actual increase in
muscle tissue strength
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-6
Conditioning Considerations
• Overload principle
• A well trained person will see relatively minor
improvements in the amount of weight that can
be lifted over a much longer period of time
– Amount & rate of progressive overload is extremely
variable and must be adjusted to match the specific
needs of the individual’s exercise objectives
– Overload is not always progressively increased
– In certain periods of conditioning, the overload
should actually be prescriptively reduced or
increased to improve the total results of the entire
program
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-7
Conditioning Considerations
• Overload principle
– Overload may be modified by changing any
one or a combination of 3 different exercise
variables - frequency, intensity, or duration
– Increasing the speed of doing the exercise,
the number of repetitions, the weight, &
more bouts of exercise are all ways to
modify these variables in applying this
principle
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-8
Conditioning Considerations
SAID Principle
• Specific Adaptations to Imposed
Demands
– the body will gradually, over time, adapt
very specifically to the various stresses &
overloads to which it is subjected
• applicable in every form of muscle training, as
well as to the other systems of body
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-9
Conditioning Considerations
SAID Principle
– Example: if an individual were to undergo several
weeks of strength training exercises for a particular
joint through a limited range of motion, the specific
muscles involved in performing the strengthening
exercises would improve primarily in the ability to
move against increased resistance through the
specific range of motion utilized
– Minimal strength gains beyond the range of motion
utilized in the training would occur usually
– Other physical fitness components such as
flexibility, cardiorespiratory endurance or muscular
endurance would be enhanced minimally, if any
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-10
Conditioning Considerations
SAID Principle
– To achieve specific benefits, exercise programs
must be specifically designed for the desired
adaption
• Adaptation may be positive or negative,
depending on whether or not correct
techniques are used and stressed in
conditioning program design & administration
– Inappropriate or excessive demands placed on the
body in too short of a time span can result in injury
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-11
Conditioning Considerations
SAID Principle
• Adaptation may be positive or negative
– If demands are too minimal or administered too
infrequently over too long a time period, less than
desired improvement will occur
• Conditioning programs & the exercises
included should be analyzed to determine if
they are using the specific muscles for which
they were intended in the correct manner
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-12
Conditioning Considerations
Specificity
• Muscular strength, muscular endurance, &
flexibility are not general body characteristics
– They are specific to each body area & muscle group
• Specific needs of the individual must be
specifically addressed when designing an
exercise program
– Often it is necessary to analyze an individual's
exercise & skill technique to specifically design an
exercise program to meet his/her needs
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-13
Conditioning Considerations
Specificity
• Addressing specific needs in designing an
exercise program
– Exercises for use in conditioning programs must be
analyzed to determine their appropriateness for the
individual's specific needs
– Exercise program goals should be determined
regarding specific areas of the body, preferred time
to physically peak, & physical fitness needs such as
strength, muscular endurance, flexibility,
cardiorespiratory endurance, body composition, etc.
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-14
Conditioning Considerations
Specificity
• Addressing specific needs in designing an
exercise program
– After establishing goals a regimen incorporating the
overload variables of frequency, intensity, & duration
may be prescribed to include the entire body or
specific areas in a manner to address the
improvement of the preferred physical fitness
components
– Regular observation & follow-up exercise analysis is
necessary to ensure proper adherence to correct
technique
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-15
Muscular Development
• One does not necessarily develop adequate
muscular strength, endurance, & flexibility
through participation in sport activities
• One needs to develop muscular strength,
endurance, & flexibility in order to be able to
participate safely & effectively in sport activities
• Adequate muscular strength, endurance, &
flexibility of the entire body from head to toe
should be developed through correctly
employing the appropriate exercise principles
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-16
Muscular Development
• Development should start at an early age &
continue throughout the school years
• Fitness tests results indicate there is need for
considerable improvement in this area
• Adequate muscular strength & endurance are
important in the adult years for the activities of
daily living, as well as job-related requirements
and recreational needs
• Many back pains and other physical ailments
could be avoided through proper maintenance
of the musculoskeletal system
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-17
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
– Thorough knowledge of muscles being used is
essential
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-18
Sit-up, bent knee
• 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
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-19
Sit-up, bent knee
Curling phase to sitting-up position
Joint
Action
Agonists
Cervical Flexion Cervical spine flexors
spine
Sternocleidomastoid
Trunk
Flexion Trunk flexors
Rectus abdominis
External oblique
abdominal
Internal oblique
abdominal
Hip
Flexion Hip flexors
Iliopsoas
Rectus femoris
Pectineus
Manual of
Structural Kinesiology
Rotating to left phase
Action
Agonists
Maintenance Cervical spine flexors
(isometric contraction)
of cervical
Sternocleidomastoid
flexion
Right lumbar Right lumbar rotators
rotation
R) Rectus abdominis
L) External oblique
abdominal
R) Internal oblique
abdominal
R) Erector spinae
Maintenance Hip flexors (isometric
of hip flexion contraction)
Iliopsoas
Rectus femoris
13-20
Pectineus
Muscular Analysis of Trunk & Lower Extremity Exercises
Sit-up, bent knee
Return phase to sitting-up position
Joint
Action
Agonists
Return phase to starting position
Action
Cervical Maintenance Cervical spine flexors Extension
(isometric contraction)
spine
of cervical
Sternocleidomastoid
flexion
Trunk
Hip
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
Maintenance Hip flexors
of hip flexion Iliopsoas
Rectus femoris
Pectineus
Manual of
Structural Kinesiology
Extension
Agonists
Cervical spine flexors
(eccentric contraction)
Sternocleidomastoid
Trunk flexors (eccentric
contraction)
Rectus abdominis
External oblique
abdominal
Internal oblique
abdominal
Extension
Hip flexors (eccentric
contraction)
Iliopsoas
Rectus femoris
Muscular Analysis of Trunk & Lower Extremity Exercises
Pectineus
13-21
Alternating Prone Extensions
• 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
• Then return to starting position
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-22
Alternating Prone Extensions
Joint
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
Trunk
Extension
Shoulder girdle adductors
Erector spinae
Splenius
Quadratus lumborum
Hip
Extension
Manual of
Structural Kinesiology
Hip extensors
Shoulder joint flexors (eccentric
contraction)
Pectoralis major (clavicular head
or upper fibers)
Deltoid
Coracobrachialis
Biceps brachii
Abduction
Trapezius
Rhomboids
Trunk extensors
Agonists in Lowering
Shoulder girdle adductors (eccentric
contraction)
Trapezius
Rhomboids
Flexion
(return to
neutral
relaxed
position)
Trunk & cervical spine extensors
(eccentric contraction)
Erector spinae
Splenius
Quadratus lumborum
Hip extensors (eccentric contraction)
Flexion
(return to
Gluteus maximus
Gluteus maximus
neutral
Semitendinosus
Semitendinosus
relaxed
Semimembranosus
Semimembranosus
position)
13-23
Muscular
Analysis of Trunk & Lower Extremity
Exercises
Biceps
femoris
Biceps
femoris
Squat
• Participant places a barbell on
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
• Return to starting position
• Ensure that the shins remain
as vertical
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-24
Squat
Joint
Hip
Action
Flexion
Knee Flexion
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
Extension
Ankle Dorsiflexion Plantar flexors
Plantar
Plantar flexors
(eccentric contraction)
flexion
Gastrocnemius
Gastrocnemius
Soleus
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
Soleus
13-25
Dead Lift
• 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
of the lift in this exercise
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-26
Dead Lift
Joint
Action
Agonists in Lifting
Wrist & hand flexors (isometric contraction)
Wrist & hand 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
Erector spinae (sacrospinalis)
Quadratus lumborum
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Knee
Extension
Manual of
Structural Kinesiology
Knee extensors (quadriceps)
Rectus femoris
Vastus medialis
Vastus intermedius
Muscular Analysis of Trunk & Lower Extremity Exercises
Vastus lateralis
13-27
Dead Lift
Joint
Wrist & hand
Action
Agonists in Lowering
Wrist & hand flexors (isometric contraction)
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)
Flexion
Hip extensors (eccentric contraction)
Erector spinae (sacrospinalis)
Quadratus lumborum
Gluteus maximus
Semimembranosus
Semitendinosus
Biceps femoris
Knee
Flexion
Manual of
Structural Kinesiology
Knee extensors (quadriceps) (eccentric contraction)
Rectus femoris
Vastus medialis
Vastus intermedius
Muscular Analysis of Trunk & Lower Extremity Exercises
Vastus lateralis
13-28
Isometric Exercises
• An 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 710 seconds for a training effect
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-29
Abdominal Contraction
• Participant 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
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-30
Leg Lifter
• Participant 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
leg
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-31
Leg Lifter
Joint
Action
Agonists in Right –
Attempting Upward
Action
Agonists in Left – Resisting
Upward
Ankle Dorsiflexion Ankle dorsiflexors
Tibialis anterior
Extensor hallucis longus
Extensor digitorum
longus
Peroneus tertius
Plantar
Flexion
Plantar flexors
Gastrocenemius
Soleus
Knee Extension
Knee extensors
(quadriceps)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Flexion
Knee flexors (hamstrings)
Biceps femoris
Semitendinosus
Semimbranosus
Hip
Hip flexors
Extension Hip extensors
Iliopsoas
Gluteus maximus
Rectus femoris
Biceps femoris
Pectineus
Semitendinosus
Sartorius
Semimbranosus
Muscular Analysis of Trunk & Lower Extremity Exercises
Tensor fasciae latae
Flexion
Manual of
Structural Kinesiology
13-32
Hip Sled
• 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
completely to move the plate
upward
• Return to the starting position
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-33
Hip Sled
Joint
Action
Ankle Plantar
flexion
Agonists in Pushing
Action
Ankle plantar flexors Dorsiflexion Ankle plantar flexors
(eccentric contraction)
Gastrocnemius
Gastrocnemius
Soleus
Soleus
Knee Extension Knee extensors
(quadriceps)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Flexion
Hip
Flexion
Extension Hip extensors
Biceps femoris
Semimembranosus
Semitendinosus
Gluteus maximus
Manual of
Structural Kinesiology
Agonists in Lowering
Knee extensors
(quadriceps) (eccentric
contraction)
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Hip extensors (eccentric
contraction)
Biceps femoris
Semimembranosus
Semitendinosus
13-34
Muscular Analysis of Trunk & Lower Extremity Gluteus
Exercises maximus
Rowing Exercise
• Participant sits on a movable
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
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-35
Rowing Exercise
Joint
Action
Foot Plantar
&
flexion
ankle
Agonists in arm pull/leg push
Ankle plantarflexors
Gastrocnemius
Soleus
Action
Agonists in return to starting
Dorsiflexion Ankle dorsiflexors
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius
Knee Extension Quadriceps (knee extensors) Flexion
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis
Knee flexors (hamstrings)
Biceps femoris
Semitendinosus
Semimembranosus
Hip
Hip flexors
Iliopsoas
Rectus femoris
Pectineus
Extension Hip extensors
Gluteus maximus
Biceps femoris
Semimembranosus
Semitendinosus
Trunk Extension Trunk extensors
Erector spinae
Manual of
Structural Kinesiology
Flexion
Flexion
Trunk flexors
Rectus abdominis
Internal oblique abdominal
13-36
Muscular Analysis of Trunk & Lower Extremity Exercises
External oblique abdominal
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
Elbow joint flexors
Wrist & hand flexors (isometric
contraction)
Agonists in return to starting
Abduction,
upward
rotation, &
elevation
Shoulder girdle adductors, downward
rotators, & depressors (eccentric
contraction)
Flexion
Shoulder joint extensors (eccentric
contraction)
Latissimus dorsi
Teres major
Posterior deltoid
Teres minor
Infraspinatus
Biceps brachii
Brachialis
Brachioradialis
Manual of
Structural Kinesiology
Action
Trapezius (lower)
Rhomboid
Pectoralis minor
Latissimus dorsi
Teres major
Posterior deltoid
Teres minor
Infraspinatus
Extension Elbow joint flexors (eccentric contraction)
Biceps brachii
Brachialis
Brachioradialis
Flexion
Wrist & hand flexors (isometric
contraction)
Flexor carpi radialis
Flexor carpi radialis
Flexor carpi ulnaris
Flexor carpi ulnaris
Palmaris longus
Palmaris longus
Flexor digitorum profundus
Flexor digitorum profundus
Flexor
digitorum
superficialis
Flexor
digitorum superficialis
Muscular
Analysis
of Trunk & Lower Extremity
Exercises
Flexor pollicis longus
Flexor pollicis longus
13-37
Web Sites
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
www.concept2.com/index.html
– 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.
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-38
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
Manual of
Structural Kinesiology
Muscular Analysis of Trunk & Lower Extremity Exercises
13-39