of tennis elbow university of 网球肘的生物力学课件

BIOMECHANICS OF TENNIS ELBOW ERICA MICHELLE FERNANDES Friday, 26 March 2010 INTRODUCTION: Incidence: Constitutes a sizeable percentage of elbow injuries Elbow problems occur atleast once in 40% to 50% of tennis players (George, et al.,2006) INTRODUCTION TO THE ELBOW JOINT BASIC ANATOMY COMMON AREAS OF INFLAMMATION SUPRACONDYLAR SUPRACONDYLAR RIDGE & EPICONDYL RIDGE & EPICONDYL FACETSFACETS TENDON BODYTENDON BODY MUSCULOTENDINOUS MUSCULOTENDINOUS JUNCTIONJUNCTION MUSCLE BELLYMUSCLE BELLY Concept of sweet spot: FORCES ACTING on the hand: Forces: EQUATIONS OF MOTION IN TENNIS 1.F+Fr=MdV/dt 2.Fb-Frh= Icmdw/dt 3.FrLf= Ifdwf/dt 4.Vp= Lfwf=hw-V Contd. Factors responsible for tennis elbow:- Poor technique Forced eccentric muscle contraction Elbow Crunch Wrist Crunch Impulse reaction Shock Tip speed Elbow crunch Before impact, Centripetal force = centrifugal force After impact, Centripetal force centrifugal force Measured in Newton: 1N=0.225 lbs. Formula: Shock*2/R. Wrist crunch: Measured from centre of mass to the wrist. Formula: Shock*2/R” (R” = distance from wrist to axis of rotation+ distance from axis to balance point. Shock: Shock= difference between initial and final kinetic energies Measured in joules High shock is bad because it means high elbow and wrist crunch. Tip speed: Low tip speed is better than a high tip speed. better racquet control more accurate Impulse reaction: Positive impulse is better since it leads to less impact force at the elbow joint. Factors to be considered to treat Tennis elbow Early phase of rehabilitation R.I.C.E PHASE 1 Goals: decrease inflammation and pain, promote tissue healing, and retard muscle atrophy. During the acute stage of your injury, whether the medial or lateral elbow is affected, follow the RICE principle: Stretching: Strengthening exercises: Phase 2: Grip strengthening,Pronation supination: Phase 3: PHASE 3 Goals: Improve muscular strength and endurance, maintain and improve flexibility, and gradually return to prior level of sport or high level activity. 15 minutes forehand only 30 minutes forehand only 30 minutes forehand and two handed backhand 45 minutes forehand and backhand 45 minutes all strokes Serve Full play Competitive play Measures to avoid Tennis elbow: ERGONOMICS Equipment modification Head size Weight of the racquet Frame Stiffness String tension Racquet material Grip size Moveable mass racquet Correct playing strategies Grip size: A grip too large or too small lessens control and pro