Biomechanics Exam 3

Flexibility Training

*goal is to increase joint ROM* -static: stretch to uncomfy length and held for about 30 to 60 seconds -ballistic: involves a bounce or swing; dangerous - PNF (proprioceptive neuromuscular facilitation): static for 30 seconds followed by isometric contraction for 5-10 seconds, then further lengthening -dynamic: take joints through ROM; continuous movements and stretch isnt held

Observation Phase: What Conditions? *Advantages and disadvantages?

- Environment: practice or competition *Practice: control the # of reps; less pressure *Competition: less reps; better performance

Anatomical Analysis: Joint Motion

- consider each phase - look at entire body - notice directions joints are moving - gravity or muscle contraction - speeding up or slowing down

What is physical training?

- directed at altering performance limitations due to physical condition of performer -Improves the components of physical fitness: strength, power, endurance, cardio fitness, flexibility, body comp

Describe the Description phase of qualitative analysis

- first step in the process -occurs in advance (before you watch movement) -Knowledge of the skill: rules and constraints, purpose or goal of skill, mechanical parameters -Characteristics or critical features: assessment of traditional technique (observe elite performers, coaching journals and workshops, personal experience)

Principle of training: Overload

- gradually increasing the exercise load an athlete undertakes to see continuous improvement -to see different and better results, athletes must alter workload EX) aerobic- inc duration or distance EX) resistance- inc reps or weight

What is the PURPOSE of the principles of training?

- programs need to be tailored to meet specific demands of athletes - training at right workload -rest periods timed correctly having all of the above= bigger improvements at faster rates

Anatomical Analysis: Rapid Acceleration and/or Impact

- to determine time(s) when large forces are most needed - to determine joint position - these are the muscles that will need to be trained -most important during fast actions

Anatomical Analysis: Extreme Joint ROM

- to determine time(s)when muscles are stretched - training to include flexibility -could indicate higher risk of injury - most important during fast actions

Instruction Phase: Communication

- verbal: what he did? what he should do? - demonstration: teacher or performer; expert vs novice -KISS principle: Keep it simple stupid -correct one error at a time -teaching cues -stay positive -remind performer about possible skill decline before they see improvement

Phase Two: Observation

- watch the actual performance

Principle of training: Training Threshold

- zones at which the athlete needs to train if they wanna see improvement and adaptation in necessary energy system -aerobic and anaerobic athletes have to train at a different percent of their max heart rate to see improvements

Describe the Instruction phase of a qualitative analysis

-4th step -aka teaching or coaching or therapy -motor learning and sport psych are involved 3 steps - communicate errors - communicate desired changes - devise means for performer to correct errors

Evaluation Phase: What to correct and in what order

-Address danger 1st -Then rank 3 categories 1) from major to minor 2) from early to late (chronological) 3) from easy to difficult in terms of time and effort to correct

Second Phase: What to Look For?

-Focus your observation on general to specific -Observe the phases of movement: preparation, force, and follow through (position of body or segments at specific times) (duration and ROM of body or segments) (velocity and acceleration) (coordination timing) -Balance issues -Use other senses: hearing a rhythm, touch or spotting, kinesthesia of athlete (ask how the performance "felt")

Second Phase: Where to Observe?

-Vantage point: primary plane of motion (perpendicular stance); how far away; multiple views -Number of observations -Value of video (extended observation)

Describe the relationship among stress magnitude, frequency, and injury

-as you increase stress you increase rate of injury -as you increase frequency, you increase rate of injury -if you increase one and not the other, the injury rate is lower

What are the aerobic methods of Training?

-continuous: same activity at same intensity for a specific time -fartlek: single activity with random varying intensities - long interval: single activity with specified changes in intensity at specific times or lengths within session; longer duration at higher intensity -circuit training: various activities done for set time

Discuss qualitative analysis to Improve Training

-deficiencies in training can limit performance - analysis to identify muscles active in performance -principle of specificity: specifically training muscles involved in activity or system -technical training -physical training: strength, power, flexibility, cardio, muscular endurance, body composition

What is technical training?

-directed at correcting or improving aspects of technique

Describe the steps of a proper anatomical analysis

-divide the skill into temporal phases - identify joints and their movements - identify muscle roles and contractions - identify rapid accelerations and impact - identify extreme joint ROM

Phase Three: Evaluation

-evaluate the novice's performance - identify errors

Discuss the stress continuum

-extremely low or extremely high stress= increase risk of injury -Eustress = Good!

Tools for measuring Kinetics

-isokinetic dynamometers -Force platforms: GRF in gait analysis, landing mechanics -Force transducers: strain gauge -Pressure sensors: in shoe, pressure mat - EMG: surface, needle, relationship between force and signal but not linear (can not quantify)

Phase One: Preparation

-know all the background knowledge - what's the purpose or goal?

Observation Phase: Who?

-knowledge of the performer: experience (novice or expert), training state, maturation (child development)

Principle of training: Reversibility

-loss of adaptations gained during training because of a prolonger break period Occurs when: -athlete is injured and has to take time off - at the end of season during recovery period -adaptations usually last at same rate they were gained *Aerobic: lost within 4-6 week; prevented with 2 minimal intensity training sessions a week *Anaerobic: lost within 1-2 weeks; slowed down by training once per week

Injury Risk

-occurs due to interaction between intrinsic and extrinsic variables -if you inc only one = safe zone -many of both= greater injury risk

Describe the negative options for an Anatomical Analysis

-palpation: touch and see it its contracting/firm - soreness -EMG (electromyography) - inverse dynamics: computer method of determining active muscles

Principle of Training: Variety

-prevents boredom and keeps athlete engaged and motivated -ensures athletes are training holistically (every muscle group or fitness component is covered and given a break)

Describe the observation phase of qualitative analysis

-second phase -includes: Who, What conditions, Where to observe, What to look for

Computer simulation and modeling

-sport: used to predict outcome based on inputs - clinical: evaluation of prosthetics - based on math - great for "what if" questions

Principle of training: Specificity

-train specifically to the energy system and skill requirements needed for sport Ex) Long distance cycler: train for longer periods with no breaks; muscular endurance in legs Ex) 100m Sprinter: train for short time with great intensity; focus on specific muscle groups

What are the 4 steps for qualitative analysis to improve technique?

1. Description (preparation) 2. Observation 3. Evaluation 4. Instruction or Intervention

Phase Four: Instruction/ Intervention

3 Basic Steps 1. Communicate with the performer 2. correct the error 3. repeat analysis

What are the 4 types of training?

Aerobic Anaerobic Flexibility Strength

What are the two types of quantitative analysis?

Basic Analysis: stop watch, counting steps, tape measure, 2D video tape Comprehensive Analysis: typically for elite athletes, research, expensive equipment

Anatomical Analysis: Temporal Phases

Continuous activities (repeat same action over and over) - running, cycling, swimming - up/down phases - heel strike/ toe off/ flight (left and right) Fast, Ballistic Activities - prep phase or wind up (go in opposite direction of movement to stretch muscles) -force production phase (moving in direction you wanna go) - follow through (slowing joint down)

How do you calculate max heart rate? Compare aerobic and anaerobic max HR

Max HR= 220-age *Aerobic= 60-80% of max HR -above= anaerobic zone -below= no improvement *Anaerobic= 80-90% max HR -below= no improvement -above= blood lactate accumulation *higher end of each zone is where most adaptation occurs*

Give examples of modifiable and nonmodifiable constraints

Modifiable: strength and flexibility Nonmodifiable: height

Instruction Phase: Correcting Error

Teaching Progression - practice discrete parts of skill - transition to next part Drills -mimic skill - slow to fast

Overuse Injuries: What determines whether or not tissue will experience a training effect (as a result of repeated loading) or result in injury?

The key appear to be adequate REST -time for remodeling to occur - without adequate recovery time, damaged tissue gets worse

True or False: Do you repeat the qualitative analysis

True

Anatomical Analysis: Active Muscles

Up= Concentric Contraction - positive work - movement and torque in the same direction - working against gravity DOWN= eccentric contraction -negative work - movement and torque in the opposite direction (movement down, torque is up) -same direction as gravity, but under control

Principle of Training: Warm Up and Cool Down

Warm Up -20 minutes - 2 phases: general (inc HR, inc Respiration, prepare muscles) specific (preform movements similar to those used in session) Cool Down -lowers areas of the body raised in the warmup -dec HR, dec respiration rate, lowers injury risk -prevents DOMS by removing built up lactic acid that is accumulated

Strength Training

Weights: dominant form; lifting weight against gravity - free weights: develops stabilizing muscles - fixed weights: uses machines and pulley system; helps learn technique - used for sports involving strength and power Elastic: elastic provides resistance to develop strength -highly portable but dont provide consistent resistance -used in rehab -used for sports that use smaller muscles Hydraulic: use of water or air compression to provide resistance -increase in resistance the faster the movement -good for sports requiring fast movements

What is qualitative analysis of human movement?

a systematic observation and introspective judgement of the quality of human movement for the purpose of providing the most appropriate intervention to improve performance -is multidisciplinary

Acute Loading

application of a single force of sufficient magnitude to cause injury to a biological tissue Ex) acl tear

Compare the different tissue thresholds

bone > tendon > ligament > cartilage

How is tissue threshold dependent on direction of load?

bone has greater resistance in compression and least in shear level *there are also individual differences

Define Injury

damage to tissue that inhibits performance

What is the purpose of a qualitative anatomical analysis method to improve training?

determine predominant muscle activity during specific phases of performance and identify where large stresses may occur

Extrinsic factors affecting injury

extrinsic= task and environment - nature of task: speed, pattern - environment: surface, equipment, weather, rules *these factors primarily affect the magnitude and frequency of applied stress

Describe the Evaluation phase of the qualitative analysis

identify errors -how does it differ from effective technique? -adverse effect or simply style difference? -due to constraints? (modifiable and nonmodifiable) danger of injury -correct these errors first!! -spotters, harnesses, crash pads, helmets prevent Who are the performers -if young or novice, focus on KEY features How easy is the correction? - how long does it take to correct? -how much time do you have to correct it? Result of another error - correct the cause first How much does error effect the performance? -can correction cause DRAMATIC improvement -is improvement negligible Due to Equipment -can different equipment correct error What to correct and in what order - address danger first

Intrinsic Factors Affecting Injury

intrinsic= body -bone density - anthropometrics (body dimensions) - fitness -injury history *these factors are related to individual ability to cope with imposed stress

Bone is anisotropic. This means...

it has different strength and stiffness depending on direction of load

Measuring Data options

lab data collection - benefit= control environment -drawback= not real life environment In field data collection -benefit= normal environment -drawback= lack of environment control sampling rate

Discuss the zones of the stress continuum

pathologic underload zone: so little stress that you are in distress and greater injury risk -Ex) bed ridden, in a cast *atrophy physiologic loading zone: amount of stress that is necessary so you are not losing mass or tissue -maintenance phase physiologic training zone: where you want to be to build tissue pathologic overload zone: too much stress; greater injury risk

What is the primary and secondary goal of biomehcanics?

primary- performance improvement secondary- injury prevention and rehab

What are the two types of biomechanical analysis?

quantitative (numbers) qualitative (quality)

Repetitive Loading:

repeated application of a subacute load that is usually of relatively low magnitude (can lead to overuse injury) Ex) stress fracture

Anaerobic Training Method

short interval method - 1:2 ration of short intense period, longer rest

Define stress 3 types?

the distribution of force (F/A) -compressive: land from a jump -tensile: ligament damage, avulsion fractures -shear

Tools of measuring KINEMATICS

timing devices -stop watch, electronic clocks and switches velocity measuring systems -radar gun, laser optical imaging systems -video and motion picture cameras (2D is one camera, 3D is two+ cameras; digitizing: to extract coordinate data) -LED cameras -Electromagnetic systems: overcome the line of sight issue accelerometers -small device that measures indirectly -uniaxial measures 1 direction -triaxial measures 3D -used in cards for airbag deployment -impact tests on helmets

What is Wolff's Law?

tissue adapts according to the stress imposed -hypertrophy= stress required -atrophy= lack of stress true for a variety of tissues (muscles and tendons, bones, ligaments)

traumatic injury

when a single application of a relatively high stress level is the injury causing factor