OVERUSE INJURIES IN RUNNING CONTENTS Overview; Basic biomechanics of running; Epidemiology of...
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Transcript of OVERUSE INJURIES IN RUNNING CONTENTS Overview; Basic biomechanics of running; Epidemiology of...
OVERUSE INJURIES IN RUNNING
CONTENTS Overview; Basic biomechanics of running; Epidemiology of running injuries; Causative factors; Dose-response relationship; and Prevention strategies Evaluation strategies
OVERVIEW Commonest type of sports in Hong Kong Mass entrants in the Tsing Ma Bridge
Marathon and ‘98 New Airport International Marathon and 10 km. run
BENEFITS OF RUNNING
Improve physical fitness level;
Positive feeling of good health;
Friendship and socialisation;
Enjoyment; and Rewards
1. Establishing the extent of the sports injury problem• Incidence• Severity
Sequence of PreventionSequence of Prevention
2. Establishing 2. Establishing aetiology & aetiology & mechanism of mechanism of injuriesinjuries
4. Assessing their 4. Assessing their effectiveness by effectiveness by repeating step 1repeating step 1
3. Introducing 3. Introducing preventive preventive measuresmeasures
EPIDEMIOLOGY OF RUNNING INJURIES Knutzen and Hart (1996) A comprehensive review on running
injuries Retrospective studies (16) Prospective studies (5) Annual incidence 48-65% (P); 24-60% (R)
EPIDEMIOLOGY OF RUNNING INJURIES
Retrospective studies Marti et al. (1980) Surveillance study of 4,358 runners in
a road race 1,994 injured (46%)
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Knee Leg and ankle Foot
Marti
PROSPECTIVE STUDY Walter et al. (1989) Ontario Cohort study enrolled 1,680 runners at two races prospective survey for 12 months. 1,288 completed the follow-up data 48% were injury.
SITE OF INJURIES
Case series studies
Clement et al. (1981) Review 1,650 patients between 78-80.
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5
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Knee Leg and ankle Foot
ClementMarti
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Knee Leg &ankle
Foot Hip Back Thigh
Walter et al.
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Knee Leg &ankle
Foot Hip Back Thigh
Walter et al.Clement et al.
EPIDEMIOLOGY OF INJURIES Data collection far from comprehensive Subjects selection bias Injuries ill-defined True incidence of injuries yet to be determined
(for details, refer to Caine et al., (1996) epidemiology of sports injuries. Human Kinetics. Chapter 22)
ESTABLISHING AETIOLOGY & ESTABLISHING AETIOLOGY & MECHANISM OF INJURIESMECHANISM OF INJURIES
RUNNING EVENTSRUNNING EVENTSRUNNING EVENTSRUNNING EVENTS CHARACTERISTICS NEURO-MUSCULAR PREDOMINANCE
(SPRINT & HURDLES) CARDIO-RESPIRATORY PREDOMINANCE
(MIDDLE & LONG DISTANCE) CAPACITY BASED ON STRENGTH &
ENDURANCE (AEROBIC & ANAEROBIC) PHYSIOLOGICAL ADAPTATION TAKING
PRECEDENCE OVER TECHNIQUE
RUNNING CYCLE
No double support phase
Stance (40%) Float (30%) Swing (30%) Contact,
midstance,propulsion forward swing & foot
descent
Jogging: Stance > Swing
Distance: Stance = Swing
Sprinting: Stance < Swing
RUNNING BIOMECHANICSRUNNING BIOMECHANICSINITIAL GROUND REACTION FORCESINITIAL GROUND REACTION FORCES
VERTICAL GROUND REACTION FORCES VERTICAL GROUND REACTION FORCES
2-3 TIMES BODY WEIGHT2-3 TIMES BODY WEIGHT ANTERIOR /POSTERIOR FORCES - 50% B.W.ANTERIOR /POSTERIOR FORCES - 50% B.W. MEDIAL /LATERAL SHEAR - 10% B.W.MEDIAL /LATERAL SHEAR - 10% B.W. DURATION - 200 - 600 ms.DURATION - 200 - 600 ms. PEAK IMPACT FORCES AT 20-30 ms.PEAK IMPACT FORCES AT 20-30 ms.
CAUSATIVE FACTORS IN RUNNING INJURIESEXTRINSIC Training error Running Terrain and Surfaces Running shoes
TRAINING ERROR Clement et al. (1981) Sudden increases in mileage or intensity High intensity without rest High level of competition
Marti et al. (1980) Increased association of injuries when
mileage (>50 km./week) Ontario Cohort study > 40 km/week.
RUNNING TERRAIN AND SURFACES
Clement et al. 1981 Uneven, hardness, road camber Uphill and downhill
RUNNING SHOES
FOOT MUST BE STABLE
SHOCK ABSORBPTION – REDUCE THE INITIAL HEEL SPIKE
RIGID LEVER FOR THE THRUST OF FORWARD MOTION
RUNNING SHOES SHOCK ABSORPTION EFFECTRUNNING SHOES SHOCK ABSORPTION EFFECT
FACTS:
The Shock absorption effect will easily lost 40% after 400-800 Km. of running
(After Cook et al 1985)
FACTS:
The Shock absorption effect will easily lost 40% after 400-800 Km. of running
(After Cook et al 1985)
CAUSATIVE FACTORS IN RUNNING INJURIESCAUSATIVE FACTORS IN RUNNING INJURIES
INTRINSIC
IMPERFECT MUSCULOSKELTAL ALIGNMENT
FLEXIBILITY
INTRINSIC FACTORS Cowan et al., 1996 Investigate effects of anatomic variation on
risk of overuse injuries Prospective study Subjects: 294 army infantry for 12/52
training Risk of injury increase with Valgus knee
(RR=1.9) and Q angle >15 degree (RR=5.4)
INTRODUCING PREVENTIVE MEASURE
PRINCIPLES OF TRAINING
BIOLOGIC ADAPTATIONS TO IMPROVE PERFORMANCE IN SPECIFIC TASKS
TRAINING PROGRAM
Yeung and Yeung 2001 Investigate the characteristics and training
profile of marathon finishers and non-finishers
Subjects: 113 runners from Standard Chartered Hong Kong Marathon 1998
Personal and training profileProfiles Finishers
(55)Non-finishers (58)
P-value
Marathon finished
4.13 0.42 0.01
Weekly training 51.94 8.57 0.00
Longest distance 27.51 5.44 0.00
Warm-up 11.02 7.65 0.06
Cool down 6.42 4.78 0.27
Optimal mileage 71.58 28.80 0.00
TRAINING AND RECOVERY
Warm (Cool) down Whirpools and Spas Massage Rest and Sleep Psychological Nutritional
COOL DOWN
Lactate can be removed from blood and muscle more rapidly by light continuous aerobic exercise
Optimal rate of removal 30 - 45% VO2 max
50-65%
OVER TRAINING Sign of over training Fatigue and poor performance Increase resting heart rate Weight loss Irritability and sleep disturbance Elevated Serum Creatine Phosphokinase
(CPK)
TRAINING TERRAIN
TRACK vs ROAD CROSS TRAINING – UPHILL vs
DOWNHILL TREADMILL
FUNCTIONAL ANATOMY OF FOOT
Normal Foot arch, flat foot and Pes Cavas
Effects of foot arch or weight bearing
SELECTION OF RUNNING SHOE
RUNNING SHOES
Be ComfortableProtect the wearer from injury Not be a source in injuryFacilitate athletic performanceBe durable and economical
SHOE COMPONENTSSHOE COMPONENTS
Last Straight / Curve Last Slip Last Board Last Shoe Upper Toe-box Heel Counter Achilles Tendon Pad Sole Outsole Midsole Insole
PRONATORPRONATOR
Needs stability and arch support Features: Straight last; Supportive heel counter; Extra support on medial side Increased medial wedging on insole Semirigid orthotic
NEUTRALNEUTRAL
Need good fit, adequate arch and shock absorbing
Features:Semicurved last;Extra cushioning & Medium heel counter
SUPINATORSUPINATOR
Needs flexibility, maximum shock absorbing
Features:Semicurved or curved last;Slip lastMaximum cushioning
ASSESSING THE EFFECTIVENESS ASSESSING THE EFFECTIVENESS OF INTERVENTIONOF INTERVENTION
A systematic review of interventions to prevent lower-limb soft-tissue running injuries
Yeung and Yeung, 2001a and 2001b
Randomised Controlled Trials
Twelve studies, with a total of 8,806 subjects met the criteria for inclusion.
three main preventive strategies for running injuries:
modification of training schedule stretching exercises use of orthotics/support or footwear
modification.
Modification of training schedule
Intervention Relative risk
Reduction of frequency of training
3/7 vs 5/7
0.19 (0.06-0.66)*
Reduction in duration of training
15-30’ vs 45’per session
0.41 (0.21-0.79)*
Reduction in running distance
280 km vs 82 km in 12 weeks
0.70 (0.54-0.91)*
STRETCHING
Stretching outside training session
Andrish et al., 1.27 (0.66-2.43)
Hartig and Henderson 0.57 (0.37-0.89)*
Stretching immediately before training session
Pope et al., 0.85 (0.43-1.67)
Pope et al., 0.83 (0.63-1.09)
Van Mechelen et al., 1.19 (0.71-1.99)
EXTERNAL SUPPORT OR FOOTWEAR MODIFICATION
Use of shocking absorbing insoles
0.87 (0.69-1.11)
Footwear modification 0.83 (0.71-0.98)*
Use of Knee brace 0.35 (0.13-0.91)*
Injuries from running can be reduced by modifying training schedules, but now guidelines are available from trials on training load. Wearing a knee brace with a patellar support ring may be effective in preventing anterior knee pain provoked by running