IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) Effect of Six Weeks Step Aerobic Training on selected Kinetic (Ground Reaction Force) and Kinematic (Temporal) Variables of Female with a Step Height of 6 inches and Intensity of 126 beats per minute Dr. Sonia Shalini*, Raghvendra Shukla**, Dr. Dhananjoy Shaw*** * Assistant Professor, I.G.I.P.E.S.S, University of Delhi, New Delhi, India ** Research Scholar, D.P.E.S.S, University of Delhi, New Delhi, India *** Officiating Principal, I.G.I.P.E.S.S, University of Delhi, New Delhi, India( Corresponding Author) A study conducted with the objective to test the effect of six weeks step aerobic training on selected kinetic (Ground Reaction Force) and Kinematic (Temporal) variables of female. The study was delimited to female subjects only (N=16), age ranging from 18 to 22 years, height of step platform set to 6 inches and intensity of training set to 126 beats per minute. The study delimited to selected kinetic (ground reaction force) variables namely as Peak Force in X-axis on Force Plate 2(PF2X), Peak Force in y-axis on Force Plate 2 (PF2Y), Peak Force in z-axis on Force Plate 2 (PF2Z), Peak Force in X-axis on Force plate 1(PF1X), Peak Force in Y-axis on Force Plate 1(PF1Y), Peak Force in Z-axis on Force Plate 1(PF1Z), Kinematic (Temporal Variables) namely as Time taken to achieve Peak Force in X-axis on Force Plate 2(TPF2X), Time taken to achieve Peak Force in Y-axis on Force Plate 2(TPF2Y), Time taken to achieve Peak Force in Z-axis on Force Plate 2(TPF2Z), Time taken to achieve Peak Force in X-axis on Force plate 1(TPF1X), Time taken to achieve Peak Force i in Y-axis on force plate 1(TPF1Y), Time taken to achieve peak force in Z- axis on force plate 1(TPF1Z). The Data Recording and quantification for pre test and post test were administered by Dynamometric Analysis (force plate recordings) was performed. Collected data were computed with mean, standard deviation and t-test. The variables namely as PF1Y, TPF1X, TPF2X, TPF2Y, TPF2Z and PF1X has significantly increased and variables PF2Y, PF2Z,, PF1Z, PF2X, TPF1Y, TPF1Z decreased significantly. Six weeks of step aerobic training were found to be sufficient length of training (training cycle) for biomechanical adaptation. All the selected kinetic (ground reaction force) and kinematic(Temporal) variables supported each other as per the existing literature or research and were found suitable for step aerobic training evaluation. Keywords: Step Aerobic Training, Ground Reaction Force Introduction Step aerobic training has gone up and down the popularity ladder over the past years. According to the latest IDEA Fitness Programs and Equipment Survey, from a peak of 86 percent of clubs offering step classes in 1997 to a low of 66 percent in 2001, the number rebounded to 82 percent in 2002—a whopping 16 percent increase in one year and more in the recent years. 1 There are various reasons for step aerobic training‟s new popularity. One of them could be that today‟s formats are a far cry from the 1995 step aerobic training classes in terms of choreography, class 1 Diane Lofshult. “Keeping Pace with Today's Step Classes.” IDEA Health Fitness Source, 6 (2003). International Research Journal of Management Science & Technology http://www.irjmst.com Page 224 IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) elements, music speed and equipment choices. Step aerobic training has emerged as a popular form of exercise in India too, being offered in a number of health and fitness centers here in our country. It has replaced or been combined with traditional aerobics in many fitness programmes. The advantage of step aerobic training is that the participants of varying aerobic fitness levels can be accommodated in the same class. Factors that can affect the aerobic requirement of step aerobic training include body weight, step platform height, stepping rate (music tempo), stepping pattern (choreography), and use of hand-held weights. By varying these factors individuals can adjust their workouts to their personal aerobic fitness levels.(Lofshult, 2003) There are different forms and variations of step aerobic training and testing but none of them are biomechanically evaluated, some of them are physiologically evaluated.The question to be answered that whether a minimum height of step with minimum possible intensity (i.e. 126 beats per minute) for six weeks, 5 days per week with a duration of 30 minutes can lead to biomechanical adaptation i.e Ground Reaction Force (GRF) parameters.(Sonia, 2010). Methodology 16 female subjects were selected for the purpose of the study. The age of the subjects ranged from 18 years to 22 years. Training for 30 min. (which included 5 min. for warm up and cool down), 5 times a week for 6 weeks. , height of step platform set to 6 inches and intensity of training set to 126 beats per minute. The nature of the study and the procedure of the testing was explained to all the volunteers in advance before the experimentation was conducted. The following Kinetic (Ground Reaction Force) Variables were selected for the study:- PF2X = Peak Force in X-axis on Force Plate 2 mounted on logs of wood PF2Y = Peak Force in y-axis on Force Plate 2 mounted on logs of wood. PF2Z = Peak Force in z-axis on Force Plate 2 mounted on logs of wood. PF1X = Peak Force in Xaxis on Force plate 1 mounted on the floor adjacent to the step platform. PF1Y = Peak Force in Yaxis on Force Plate 1 mounted on the floor adjacent to the step platform. PF1Z = Peak Force in Zaxis on Force Plate 1 mounted on the floor adjacent to the step platform. TPF2X = Time taken to achieve Peak Force in X-axis on Force Plate 2 mounted on logs of wood. TPF2Y = Time taken to achieve Peak Force in Y-axis on Force Plate 2 mounted on logs of wood. TPF2Z = Time taken to achieve Peak Force in Z-axis on Force Plate 2 mounted on logs of wood. TPF1X= Time taken to achieve Peak Force in X-axis on Force plate 1 mounted on the floor adjacent to the step platform. TPF1Y = Time taken to achieve Peak Force i in Y-axis on Force Plate 1 mounted on the floor adjacent to the step platform. TPF1Z = Time taken to achieve Peak Force in Z-axis on Force Plate 1 mounted on the floor adjacent to the step platform. The study was conducted by adopting test-retest design. According to the design of the study, all the subjects were tested (pre test) before step aerobic training. Thereafter, step aerobic training was given for a period of six weeks to the selected subjects as per the protocol. After six weeks of training the subjects were retested (post test). The recording was taken at Human Ergonomics Laboratory, DIPAS, Delhi. Each recording duration was 10 seconds for each subject. Note: The post test was conducted for subjects who had completed their respective training protocols for a minimum of five days a week for a period of six weeks. International Research Journal of Management Science & Technology http://www.irjmst.com Page 225 IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) Force Plate 1 on the floor Force Plate 2 mounted on logs of wood Wooden Plank Step Platform Figure 1: Aerobic Training Set Up Table 1 List of Abbrevations Abbrevations Name of Variables PF2X Peak Force in X-axis on Force Plate 2 mounted on logs of wood at 6” height PF2Y Peak Force in y-axis on Force Plate 2 mounted on logs of wood at 6” height PF2Z Peak Force in z-axis on Force Plate 2 mounted on logs of wood at 6” height PF1X Peak Force in X-axis on Force plate 1 mounted on the floor adjacent to the step platform PF1Y Peak Force in Y-axis on Force Plate 1 mounted on the floor adjacent to the step platform PF1Z Peak Force in Z-axis on Force Plate 1 mounted on the floor adjacent to the step platform TPF2X TPF2Y Time taken to achieve Peak Force in X-axis on Force Plate 2 mounted on logs of wood Time taken to achieve Peak Force in Y-axis on Force Plate 2 mounted on logs of wood TPF2Z Time taken to achieve Peak Force in Z-axis on Force Plate 2 mounted on logs of wood TPF1X Time taken to achieve Peak Force in X-axis on Force plate 1 mounted on the floor adjacent to the step platform. Time taken to achieve Peak Force i in Y-axis on Force Plate 1 mounted on the floor adjacent to the step platform. Time taken to achieve Peak Force in Z-axis on Force Plate 1 mounted on the floor adjacent to the step platform TPF1Y TPF1Z Pre Test Test conducted before starting the experimental treatment Post Test Test conducted after six weeks of step aerobic training. International Research Journal of Management Science & Technology http://www.irjmst.com Page 226 IRJMST ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) Vol 8 Issue 11 [Year 2017] Statistical Analysis The data obtained was analyzed by computing the mean, standard deviation and two tail „t‟ test by difference method was computed to these paired observations of protocol experiment for the selected kinetic (ground reaction force) variables. The research hypothesis was tested using the following formula: t d N d 2  (d) 2 N where, N = Sample Size Σd = Su Total of Differe e etwee Pre Test a d Post Test Σd2 = Sum Total of Square of Difference between Pre Test and Post Test Σd 2 = Whole Square of Sum of Difference between Pre Test and Post Test The level of significance chosen was 0.05 for testing the hypothesis. Table :-2 Effect of Step Aerobic Training for Six Weeks with 6 inch Step Platform at 126 Beats Per Minute (BPM) on Kinetic (Ground Reaction Force) and Kinematic (Temporal) Variables S. No. VARIABLE TEST MEAN SD ΣD ΣD2 (ΣD)2 t 1. PF2X 952615.52 7.50* 575.00 19049.02 330622.99 6.16* 3. PF2Z 801.90 29390.06 643041.64 8.32* 4. PF1X 895.79 48868.87 802439.45 5.81* 5. PF1Y 786.81 27883.23 619068.84 8.52* 6. PF1Z 2369.15 279421.59 4620.49 4.48* 7. TPF2X 34.62 68.41 1198.54 6.22* 8. TPF2Y 80.76 476.76 6522.18 4.89* 9. TPF2Z 30.74 45.27 944.95 7.75* 10. TPF1X 67.88 176.91 4607.69 11.83* 11. TPF1Y 118.69 4327.43 14086.15 1.90(NS) 12. TPF1Z 12.44 18.65 18.13 13.47 64.99 75.36 15.69 21.15 16.40 31.08 149.44 139.07 0.51 0.35 1.05 2.87 0.91 0.90 0.78 1.91 1.57 1.39 1.55 2.00 46691.42 PF2Y 48.43 34.36 50.29 49.04 543.75 541.39 43.71 44.98 51.50 60.97 803.97 801.74 2.11 2.55 1.55 3.63 1.89 2.55 5.53 6.27 8.07 5.93 7.02 5.42 976.02 2. Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test Pre Test Post Test 51.24 113.20 2625.54 9.18* International Research Journal of Management Science & Technology http://www.irjmst.com Page 227 IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) Note:*Significant at 0.05 level, N = 32 , Time = ms, Force= N The analysis of data in Table 2 documents the mean, standard deviation and „t‟ ratio of kinetic (ground reaction force) variables PF2X, PF2Y, PF2Z, PF1X, PF1Y, PF1Z TPF2X,TPF2Y, TPF2Z, TPF1X, TPF1Y and TPF1Z recorded at pre test and post test. According to the table the mean and standard deviation of PF2X pre test was 48.43± 12.44 and post test was 34.36± 18.65, with significant „t‟ ratio (t= 7.50) at.05 level. Mean and standard deviation of PF2Y pre test was 50.29 ± 18.13 and post test was 49.04 ± 13.47 with significant „t‟ ratio (t= 6.16 ) at.05 level. Mean and standard deviation of PF2Z pre test was 543.75 ± 75.36 and post test was 541.39 ± 63.39 with significant „t‟ ratio (t= 8.32) at.05 level. Mean and standard deviation of PF1X pre test was 43.71 ± 15.69 and post test was 44.98 ± 21.15 with significant „t‟ ratio (t= 5.81) at.05 level. Mean and standard deviation of PF1Y pre test was 51.50 ± 16.40 and post test was 60.97 ± 21.08 with significant „t‟ ratio (t= 8.52 ) at.05 level. Mean and standard deviation of PF1Z pre test was 803.97± 149.44 and post test was 801.74 ± 139.07 with significant „t‟ ratio (t= 4.48) at.05 level. Mean and standard deviation of TPF2X pre test was 2.11 ± 0.51 and Post Test was 2.55 ± 0.35 with significant „t‟ ratio (t= 6.22 ) at.05 level. Mean and standard deviation of TPF2Y pre test was 1.55± 0.05 and post test was 3.63 ± 2.87 with significant „t‟ ratio (t= 4.89 ) at.05 level. Mean and standard deviation of TPF2Z pre test was 1.89± 0.91and post test was 2.55± 0.90 with significant „t‟ ratio (t= 7.75 ) at.05 level. Mean and standard deviation of TPF1X pre test was 5.53± 0.78 post test was 6.27± 1.91 with significant „t‟ ratio (t= 11.83) at.05 level. Mean and standard deviation of TPF1Y pre test was 8.07± 1.57 post test was 5.93±1.39 with insignificant „t‟ ratio (t= 1.90) at.05 level. Mean and standard deviation of TPF1Z pre test was 7.02 ± 1.55 post test was 5.42 ± 2.00 with significant „t‟ ratio (t= 9.18 ) at.05 level. Discussion of Findings 900 800 700 600 500 400 300 200 100 0 MEAN SD Pre Post Pre Post Pre Post Pre Post Pre Post Pre Post Test Test Test Test Test Test Test Test Test Test Test Test PF2X PF2Y PF2Z PF1X PF1Y PF1Z 1 2 3 4 5 6 Figure No-2:- Training Effects on GRF (Ground Reaction Force) Variables International Research Journal of Management Science & Technology http://www.irjmst.com Page 228 IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) 9 8 7 6 5 4 3 2 1 0 MEAN SD Pre Post Pre Post Pre Post Pre Post Pre Post Pre Post Test Test Test Test Test Test Test Test Test Test Test Test TPF2X TPF2Y TPF2Z TPF1X TPF1Y TPF1Z 7 8 9 10 11 12 Figure No-3:- Training Effects on Temporal Characteristics on Ground Reaction Force (GRF) Conclusions It was concluded that there was significant effect of step aerobic training on the selected kinetic and kinematic variables which are given below:1. Peak Force in X-axis on Force plate 1 mounted on the floor adjacent to the step platform (PF1X) was significantly increased. 2. Peak Force in Y-axis on Force Plate 1 mounted on the floor adjacent to the step platform (PF1Y) was significantly increased. 3. Peak Force in Z-axis on Force Plate 1 mounted on the floor adjacent to the step platform (PF1Z) was significantly decreased. 4. Peak Force in X-axis on Force Plate 2 mounted on logs of wood at 6” height (PF2X) was significantly decreased. 5. Peak Force in y-axis on Force Plate 2 mounted on logs of wood at 6” height (PF2Y) was significantly decreased. 6. Peak Force in z-axis on Force Plate 2 mounted on logs of wood at 6” height (PF2Z) was significantly decreased. 7. Time taken to achieve Peak Force in X-axis on Force plate 1 mounted on the floor adjacent to the step platform (TPF1X) was significantly increased. 8. Time taken to achieve Peak Force i in Y-axis on Force Plate 1 mounted on the floor adjacent to the step platform (TPF1Y) was significantly decreased. 9. Time taken to achieve Peak Force in Z-axis on Force Plate 1 mounted on the floor adjacent to the step platform (TPF1Z) was significantly decreased. 10. Time taken to achieve Peak Force in X-axis on Force Plate 2 mounted on logs of wood (TPF2X) was significantly increased. 11. Time taken to achieve Peak Force in Y-axis on Force Plate 2 mounted on logs of wood (TPF2Y) was significantly increased. 12. Time taken to achieve Peak Force in Z-axis on Force Plate 2 mounted on logs of wood (TPF2Z) was significantly increased. International Research Journal of Management Science & Technology http://www.irjmst.com Page 229 IRJMST Vol 8 Issue 11 [Year 2017] ISSN 2250 – 1959 (0nline) 2348 – 9367 (Print) Acknowledgement A special thanks to Dr. D. 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