Teri McCambridge, MD, FAAP Assistant Professor of Pediatrics Johns Hopkins School of Medicine.
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Transcript Teri McCambridge, MD, FAAP Assistant Professor of Pediatrics Johns Hopkins School of Medicine.
Teri McCambridge, MD, FAAP
Assistant Professor of Pediatrics
Johns Hopkins School of Medicine
Teri Metcalf McCambridge
A. I have no relevant financial relationships
with the manufacturer's) of any commercial
product(s) and/or provider of commercial
services discussed in this CME activity.
B. I do not intend to discuss an
unapproved/investigative use of a commercial
product/device in my presentation.
Case I:
9 year old male football player wants to begin a
strength training program, but his mom has heard he
will not demonstrate increases in strength until
puberty and that it is dangerous.
What do you advise?
Appropriate age to begin
strength training?
Attained the ability to follow rules
Achieve balance and
postural control (age 7-8)
Proficiency in their sport
Common sense
Lack of androgenic hormones?
Whose idea?
What’s the motive?
Richard Santrak
Is it efficacious?
Why the controversy?
Initial Studies
revealed:
No increase in
muscle strength
No increase in
muscle crosssectional area
Vrijens J Med Sport 1978;
11:152-158
1983 AAP Statement
Committee on Sports
Medicine
“Pre-pubescent boys
(tanner stage 1-2)
demonstrate no
significant increase in
strength or muscle mass
because of lack of
androgens”
Deficiencies of early research
Children naturally increase strength as they grow and
mature, must have adequate controls
Studies were short duration
Studies evaluated low intensity training volumes
(Sets x repetitions x load)
Overall inadequate studies
Recent Research Demonstrates Significant
Gains:
Sewall, L, Micheli LJ: J Pediatric
Orthop 1986;6:143-146
Weltman A, et al. Med Sci Sports
Exerc 1986; 18:629-638
Faigenbaum, AD, et al. Pediatr
Exerc Sci. 1993; 5:339-46.
Faigenbaum, AD,. et al. J
Strength and Cond Res 1996;
10(2):109-114
Falk B, et al. Sports
Med.1996;22(3):176-186
Faigenbaum AD J Strength Cond
Res 2001;15:459-465.
Strength gains between
36%-74.3%
No effect on flexibility
No effect on vertical
jump
Mechanism of Strength Gains?
Not Muscle Hypertrophy
As measured by CT scanning
Occurs in boys and girls equally
Strength gains dependent
on increased motor unit:
Activation/recruitment
Coordination
Firing
8 weeks required
Ozmun, J Mikesky A. Med Sci Sports
Exerc 1994;26:510-514
Current AAP Policy Statement:
2001-”Studies have shown that strength training,
when properly structured with regard to freq,
mode, intensity, and duration increases in strength
in pre-adolescents without muscle hypertrophy”
2008-”Agree with above and Olympic weight
lifting may be safe in closely supervised settings
but more research is needed to recommend.”
Is it Safe?
Why the concern?
Initial NEISS reports
1979 half of 35, 512 weight lifting injuries involved 10-19
year olds
1987 report revealed 8590 children 14 and under were
treated in emergency department with weight lifting
injuries
1991-1996 20k-26k equipment associated injuries
occurring annually
Problems with using this data to
determine safety:
Does not distinguish between resistance training and
competitive weight lifting
Information is based on patient report of injury
Does not distinguish between supervised and
unsupervised injuries
Does not report if weights were utilized properly
Is it Safer than some Sports?
Study by Hamill
suggests strength
training is safer than
participation in:
Soccer
Basketball
Football
General play
Hamill B. J Strength Cond Res 1994;8:53-57
Recent literature: CPSC NEISS
Accidental weight training Injuries
Myer GD. J Strength Cond Res 2009; 23(7) 2054:2060
Considered Safe:
Proper Equipment
Proper Form
Proper Supervision
Certified or Trained
individual
Ratio of Adult to
Student (1:10)
Health Risks--Stunted Growth?
Concerns
Arouse out of studies in
Japan
Children performing heavy
labor
Resulted in “stunted growth”
Nutritional deficiencies or
labor?
Data of well
controlled/designed
studies no effect on growth
or epiphyseal plates
CASE 1
Can the 9 year old begin a strength training program?
What’s the reason?
Is there supervision?
Is it necessary?
Is it appropriate?
Case 2:
14 year old tanner Stage 3 male basketball player wants
to begin the “clean and jerk” and “snatch”
What is your opinion of these lifts?
Should this be a bigger concern?
Strength Training/
Resistance training
“Specialized method
of physical
conditioning that is
used to increase one’s
ability to exert or
resist force”
Methods?
Free weights
Weight Machines
Weight plates
Hydraulics
Bands/Balls
Body weight
Kettle balls
Other Forms:
Brief Discussion:
Competitive Weightlifting
(Olympic)
Minimal Discussion
Power Lifting
Competitive sport that
involves maximum lifting
ability
Lifts: Snatch and Clean and
Jerk
Competitive sport
involving maximum lifts
Dead lift, squats, and
bench press
Body Building
Competition that judges
muscle size definition,
and symmetry
Plyometrics
(Stretch-Shortening Cycle)
Safe and worthwhile
method of conditioning
Typically includes hops
or jumps
Cautious of too many
repetitions
The “Power Clean”
“Clean and Jerk”
The “Snatch”
“Dead Lift”
Is Olympic Weightlifting Safe?
Data suggests safety in
well supervised
settings
Study at the USA
Weightlifting
Development Center
Byrd R, Pierce K, et al.
Sports Biomech
2003;Jan 2(1): 133-40
The AAP’S Policy (2008)
Safe in Well controlled studies, emphasizing proper
technique
Do not yet recommend for general population
Concerns regarding improper technique and injury
risk
Impetus for childhood involvement?
What’s Really Happening
Survey of HS S&C
coaches
38 of 128 Responded
37 of 38 use Olympic –
Style lifting
Duehring MD, J Strength Cond Res 2009; 23(8)2188-2203
Severe Injuries associated with improper
Olympic lifting
Bilateral Distal Radial
and Ulnar Fractures
Disc Herniation
Spondylolysis and
Spondylolisthesis
ASIS pelvic avulsion
fracture
Scaphoid fracture
Death
CASE 2
What’s the difference between strength training and
competitive weightlifting?
Why the distinction when recommending children’s
participation?
Case 3:
A 12 year old female soccer players’ parents wants to
know if strength training can:
Prevent an ACL tear?
Improve sports performance in the pre-adolescent?
Provide permanent strength gains once a program is
completed?
Injury Prevention with Strength Training?
Less Shoulder pain in Adolescent Swimmers
Dominquez, Swimming Medicine IV 1978: 105-109
Decreased incidence and severity of knee injury with
preseason training
Cahill B, Griffith E. Am J Sport Med 1978; 6:180-184
ACL prevention with Plyometric jump training
program
Hewett, TE, et al. Am J Sport Med 1999; 27:699
More Evidence to follow?
Benefits? Anaerobic Power?
30 Prepubescent male athletes
12 week strength training with free weights and
machines. 3x/week
Outcome variables: vertical jump, 40 yd dash, and
Wingate test
Results: Vertical jump improved, but no other
measures of anaerobic power
Hetzler, RK, Coop D, et al. J Strength Cond. Res.
1997; 11(3):174-181
Sports Performance?
Inconclusive evidence
Evidence for improved
vertical jump
long jump
sprint speed
Medicine ball toss
Translation into improved
performance is inconclusive
Limited evidence
improvement
Hoffman JR (football) J strength Cond Res 2005; 19(4):810-815
Faigenbaum A. Phys Edu 2006; 63: 160-67.
Christou M. (soccer) J Strength Cond Res 2006 20(4), 783-791
Strength Training and Detraining
Recommend
Frequency in children
2x/week training
Detraining
Loss of strength about
3% week
Faigenbaum AD, et al.
Res Quarterly Exercise
Sport, 2002; 73(4):
416-424.
Despite athletic
participation
Faigenbaum, AD, et al.
J Strength and Cond Res
1996; 10(2):109-114
CASE 3
Strength training is not the “end-all-be-all” for sports
Just one component of various training methods
“Prehabilitation” strengthening may have some
promise
Performance benefit lacking at this time
Case 4
A 15 year old, with a past medical history of Childhood
leukemia, wants to begin a strength training
program—Is there any evaluation required prior to
participation?
Athletes requiring clearance prior to
participation
Uncontrolled severe hypertension
Previous treatment with anthracycline
chemotherapeutic agents
Uncontrolled seizure disorder
Underlying neuromuscular disorder (Cerebral Palsy,
etc.)
Cardiology consultation recommended if history
of:
Hypertrophic
Cardiomyopathy
Moderate-Severe
pulmonary
hypertension
Uncontrolled
Hypertension
Marfan’s Syndrome
with a dilated aorta
Aortic Root dilatation in Elite
Strength Trained athletes
100 Elite Strength trained athletes
Age mean 22.1 + 3.6 years
128 healthy age and height matched control
Results Aortic root diameters were significantly greater
in all 4 locations of measurement, with progressive
enlargement noted based on duration of high intensity
lifting.
Am J Cardiology 2007: 100:528-530
Past Medical History:
Childhood Leukemia/Oncology
Patient’s treated with high dose (500
mg/M2)anthracycline therapy are at risk for acute
cardiac decompensation with initiation of weight
training
Cardiology/Oncology input required prior to program
initiation
Steinherz, Laurel, et al. Cardiac Toxicity 4 to 20
years after completing anthracycline therapy
Jama 1991; 266 (12): 1672-1677.
CASE 4
Usual preparticipation guidelines exist
Be aware of new recommendations, such as for young
cancer survivors
Case 5.
The parents of a 14 year old want to enroll their child
in a strength training program. They bring in a list of
questions including:
Guidance on a proper strength training program
How to evaluate a personal trainer’s credentials
List of respected sports training facility in your area
Initiating a Weight Training
Program
What
you
need
to
know!
Guidelines have been established by
The AAP, AOSSM, and NSCA
General Recommendations
(program)
10 minutes dynamic warm-up and cool down
Program should include 1-3 sets of 6-15 reps of 6-8
exercises
Include all muscle groups and a full ROM at each
joint
Focus on technique and proper form
Recommend 2-3 non-consecutive training
sessions/wk for 20-30 min
Increase resistance gradually
.
Program
varied over time
Faigenbaum AD. Clinics in Sport Med; 19 (4): 2000
Examples of exercises to incorporate into a
beginning program
Single joint
Leg extension
Multi-joint
Squats
Plyometrics
Squat jumps, medicine
ball chest passes
Core strengthening
Sit-ups, back extensions
Means of progressing a program
Increase the resistance
Generally 5-10% increase in training load
Increase repetitions
Increase number of sets
Recommendations for Parents evaluating a
program
Qualifications of Instructor
Student : Teacher ratio
Modes of strength training that will be utilized
Evaluate weight stack increments (1-5 pounds in
children)
Weight machine sizes
Will 1 weight rep max be used
Performance of Olympic or power lifts
Special Recommendations for
Youth Strength training
Consider decreasing training volume and intensity
during rapid growth
Emphasize flexibility
Stress importance of proper lifting techniques not
amount of weight lifted
Controlled movements
Proper breathing
Recommend against competitive weight lifting,
power lifting, and body building until skeletally
mature
Evaluating Strength Training Credentials
Is the program NCCA certified?
Do they require re-certification and CEU’S?
Are there minimum requirements?
Is the exam proctored and does it have a practicum?
How long have they been certified?
What Credentials are recommended for Strength
and Conditioning Specialists?
National Strength and
Conditioning
Association
American College of
Sports Medicine (ACSM)
CSCS
ACSM Health Fitness
NSCA-CPT
Instructor
ACSM Exercise
Specialist
American Council on
Exercise
National programs for youth strength
training?
Velocity sports performance
http://www.velocitysp.com/
Competitive Athletic Training Zone (CATZ)
http://www.catzsports.com/
Case 6:
Are there special patient populations in your practice
that could benefit from a strength training exercise
prescription?
Overweight or “At Risk” for overweight patients
Cerebral Palsy
Osteoporosis or Osteopenia
Benefits: Particular benefit for the
overweight child?
Cardiovascular fitness
Body composition
Bone mineral density
Blood lipid profile
Mental Health
Anxiety
Self-concept
Benefits: Cerebral Palsy
Increased strength
Improved overall function
Improved Mental Well-being
Blundell S. Clin Rehab 2003;17: 48-57
McBurney H. Dev Med Child Neuro 2003; 45:658-663
Benefits: Bone mineral density
Prevention of Osteoporosis
Adolescent bone is responsive to the osteogenic
stimulus of heavy resistance training
Bone density of junior Olympic weight lifters was
greater than age matched controls and normal adult
bone density
Conroy BP. Med Sci Sport
Exerc. 1993;25:1103-9
Why Are Kids Strength Training?
Fun?
Improve Performance?
Parental Pressures?
Will they burn out?
Should they be
spending more time
“playing” sports?
AAP Recommendations:
Prevention Overuse and Burnout
Limit activity to 1
sporting activity a
maximum of 5 days a
week.
One day off from any
organized physical
activity per week
2 to 3 months off per
year from their sport
Food for Thought!
0.2-0.5 % of high school
athletes ever make it to
the professionals.
Variety is the spice of life
References:
AAP COSMF Policy Statement. Strength training by
Children and Adolescents Pediatrics 2008 121(4):83540.
AAP Overuse Injuries, Overtraining, and burnout in
Child and Adolescent Athletes. Pediatrics 2007;
119(6):1242-1245.
Youth Resistance Training: Position Statement Paper
and Literature Review. J Strength Cond Res 2009
23(4):1-20.
Thank you!