Force generated by a muscle Essays

Power produced by a muscle Essays Power produced by a muscle Essay Power produced by a muscle Essay Assess Force-Angle Relationships using EMG and Force Measurements Q1. From the single normal informations [ table 1 ] we got by normalization ( As % of Maximum using as cleanser esteems: FORCEmax=117.2 N, EMGmax=306.8 millivolt ) the balanced single informations [ table 2 ] . Q2. Electromyography is the procedure for entering changes in the electrical intensity of a musculus when it is caused to shrink by an engine nervus ask ( Barlett, R.1997 ; 228 ) The EMG signal profile and in actuality the EMG is the electrical sign profile distinguished by a cathode on a musculus. At the end of the day is the progression of the activity power of the external muscle-fiber film ( the sarcolemma ) . [ 3 ] : Power produced by a musculus is dictated by two boss factors: the figure of engine units ( MUs ) effectively invigorated at a similar clasp and the frequence ( terminating rate ) at which the MUs are terminating. Other than the abundancy of the EMG signal relies upon both the figure of dynamic MUs and their fire rates. Since both EMG plentifulness and power expansion as an impact of similar instruments, it is normal that musculus power can be evaluated from surface EMG examination. This is non rather obvious yet only in isometric withdrawals, where musculus electrical action and musculus power have a similarly added substance relationship. [ 3 ] This is the main ground why EMG is the strategy for pick for power examination. Q3. Utilizing Normalized EMG and Joint Angle data from [ table 2 ] , the mentioned chart is appeared underneath [ diagram 2 ] Assess Force-Angle Relationships using EMG and Force Measurements Q4. From the line informations for the entire gathering we ascertain the normal standardized qualities as in [ table 3 ] . Utilizing informations for Max isometric power and EMG from [ table 3 ] , the mentioned diagram is chart 3 underneath. Q5. Assess Force-Angle Relationships using EMG and Force Measurements Assess Force-Angle Relationships using EMG and Force Measurements Q6. Utilizing the free-body graph ( fig. 1 ) at a conventional edge? we sketch the powers proceeding onward the lower arm during flexure against a known resistance. These powers are the resistance R, the mass of the lower arm G, the endeavor E of the musculus and the joint response power Fj. The joint response compel as go throughing from the focal point of rotating movement has no part to the moment at the joint and thusly is disregarded. Accepting latent harmony at each point, the measure of minutes proceeding onward the lower arm at the cubitus peers zero: SMj = 0 Mj = ME MR MG [ 1 ] MR = R Lf mischievousness? [ 2 ] , where Lf is the length of the lower arm. MG = medium recurrence g LCM mischievousness? [ 3 ] , where LCM is the separation of the lower arm s focus of mass from the joint and medium recurrence is the mass of the lower arm and manus. ME = E? LE where E? is the rotational constituent of the endeavor E. ME = E LE sinf [ 4 ] , where degree Fahrenheit is the edge between the long pivot of the lower arm and the line of utilization of the endeavor power and LE is the endeavor arm ( typical separation between the purpose of introduction of the musculus on lower arm and the joint ) . Subbing the different minutes [ 2 ] , [ 3 ] , [ 4 ] in condition [ 1 ] we acquire, using the shows of the imprints: Mj = E LE sinf Roentgen Lf devilishness? medium recurrence g LCM fiendishness? [ 5 ] To figure the Torque using condition [ 5 ] we should cognize Lf, LE, LCM, degree Fahrenheit, medium recurrence ( R, E and? known, g = 9.81 ms-2 ) . Condition [ 5 ] figures the torsion using latent balance at each edge and assuming that the length of the musculus stay unchanging as joint point changes, which is non valid. For an increasingly precise calculation we other than need to cognize the connection between constriction power and obliged musculus length. Assess Force-Angle Relationships using EMG and Force Measurements Q7. Normalization is the numerical look of the sufficiency of the EMG signal as a proportion to the plentifulness of a constriction esteemed to be maximal ( top EMG from an isometric maximal deliberate compression ( MVC ) of a similar musculus ) . EMG signal has an unpredictable nature and the record that just the figure of dynamic engine units and their fire rates can affect it is semplicistic. In world anatomical, physiological and capable components have impact on the electromyographical signal. In a reappraisal of such factors ( De Luca, 1997 ) assembled them as causative, moderate and deterministic. A portion of these variables are: musculus fiber width, figure of musculus filaments, terminal skin interface, signal molding, figure of dynamic engine units, tissue entirety, good ways from skin surface to muscle fiber, musculus fiber conductivity speed, musculus blood stream, basic cathode separating, fiber type and area, engine unit terminating rate. [ 2 ] As a result of the above variables furthermore for grounds of direct contrasting of EMG signals recorded and flags from a similar musculus on various events or from various musculuss and various people we use standardized EMG flags rather than total qualities. Notices Barlett, R. ( 1997 ) Introduction to Sports Biomechanics, Taylor A ; Francis e-Library, 2002. Carl J. Payton, Biomechanical Evaluation of Movement in Sport and Exercise, Taylor A ; Francis e-Library, 2007. Hamill, Joseph ; Knutzen, Kathleen M. , Biomechanical Basis of Human Movement, third Ed, Lippincot A ; Wilkins, 2009.