The aim of this study was to analyze the relationships between “Sailor’s jigs” kinematic and increasing music cadence. Six young women with at least one year of experience conducting this type of head-out aquatic programs, with no kind of skeletal muscle injury reported on the last six months and non-pregnant were evaluated. The exercise was recorded on video, in the frontal plane, using a pair of cameras, enabling a double projection, from above and underwater body motions, at five increasing cadences (120 b.min-1, 135 b.min-1, 150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter digitized in specific software (Ariel Performance Analysis Systems). The cycle period decreased through the incremental protocol. Cycle period decrease is done decreasing joints range of motion and increasing the limbs segmental velocity as well. Although these combined kinematical strategy, a deeper analysis reveals that subjects decrease the cycle period mainly decreasing the range of motions

Barbosa, Tiago M.

Costa, M.J.

Marinho, D.A.

Oliveira, C.

Silva, A.J.

Teixeira, Genoveva

The aim of this study was to analyze the relationships between
“Sailor’s jigs” kinematics and increasing music cadence. Six young
women, non-pregnant, with at least one year of experience conducting
this type of head-out aquatic program, with no kind of skeletal
muscle injury reported in the last six months were evaluated. The
exercise was recorded on video, in the frontal plane, using a pair of
cameras, enabling a double projection, from above and underwater
body motions, at five increasing cadences (120 b.min-1, 135 b.min-1,
150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter
digitized in specific software (Ariel Performance Analysis Systems).
The cycle period decreased through the incremental protocol. Cycle
period decrease is done decreasing joint range of motion and increasing
the limbs segmental velocity as well. Although these combined
kinematical strategy, a deeper analysis reveals that subjects decrease
the cycle period mainly decreasing the range of motion

Biblioteca Digital do IPB

12Head-out aquatic exercise “sailer’s jigs” kinematics at increasingmusical cadence.Genoveva Teixeira1, Cristiana Oliveira1, Mário J Costa2, Daniel A Marinho3, António J Silva1,Tiago M Barbosa21University of Trás-os-Montes and Alto Douro/CIDESD, Vila Real, Portugal2Polytechnic Institute of Bragança/CIDESD, Bragança, Portugal3University of Beira Interior/CIDESD, Covilhã, PortugalThe aim of this study was to analyze the relationships between“Sailor’s jigs” kinematics and increasing music cadence. Six youngwomen, non-pregnant, with at least one year of experience conduct-ing this type of head-out aquatic program, with no kind of skeletalmuscle injury reported in the last six months were evaluated. Theexercise was recorded on video, in the frontal plane, using a pair ofcameras, enabling a double projection, from above and underwaterbody motions, at five increasing cadences (120 b.min-1, 135 b.min-1,150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafterdigitized in specific software (Ariel Performance Analysis Systems).The cycle period decreased through the incremental protocol. Cycleperiod decrease is done decreasing joint range of motion and increas-ing the limbs segmental velocity as well. Although these combinedkinematical strategy, a deeper analysis reveals that subjects decreasethe cycle period mainly decreasing the range of motion.IntroductionHead-out aquatic classes are often full with dozens of subjects, givinginstructors a greater challenge to maintain synchronization. Instruc-tors use music cadence on a regular basis for such purpose. Added tothat, music’s melody and cadence are a way to motivate subjects,achieving a given intensity of exertion (Kinder and See, 1992).Basic head-out aquatic exercises are categorized in six main groups(Sanders, 2000): (i) walking; (ii) running; (iii) rocking; (iv) kicking;(v) jumping and; (vi) scissors. Some researchers analyzed the rela-tionships between musical cadence and some of those basic head-outaquatic exercises (e.g., Oliveira et al., 2010; in press). However, itseems none of them focused on the “sailor’s jigs” exercise.The aim of this study was to analyze the relationships between “sailor’sjigs” kinematics and increasing music cadence. It was hypothesizedthat increasing musical cadence will decrease the cycle period and,therefore, the segmental range of motion.MethodsSubjects: Six young women, non-pregnant, clinically healthy andphysically active, holding a graduate degree in Sports Sciences andwith at least one year of experience conducting head-out aquaticclasses, volunteered to participate in this study (23.50 ± 3.51 years-old; 57.17 ± 4.07 kg of body mass; 1.66 ± 0.06 m of height; 20.60 ±0.55 kg/m2 of body mass index; 270.00 ± 80.50 minutes of aquaticfitness classes per week). Subjects reported no previous history oforthopedic or muscle-skeletal injuries in the previous six months. Allprocedures were in accordance with the Declaration of Helsinki withrespect to human research. The Institutional Review Board of thePolytechnic Institute of Bragança approved the study design.Womenwere informed of the experimental risks and signed an informed con-sent document before the investigation.ProceduresEach subject performed a basic head-out aquatic exercise named“sailor’s jigs”. The exercise was performed using ‘‘water tempo’’according to the standard recommendations from the technical liter-ature (Kinder and See, 1992) that was already reported in some sci-entific papers as well (e.g., Barbosa et al., 2010a).The protocol consisted of five sets of 16 full repetitions of the “Sailor’sjigs” exercise, at “water tempo”, immersed to the xiphoid process (i.e.,breast). The intensities of the bouts were 80 [%], 90 [%], 100 [%],110 [%] and 120 [%] of the cadence reported by Barbosa et al.(2010a) to achieve a 4 [mmol.l-1] of blood lactate, representing 120[b.min-1], 135 [b.min-1], 150 [b.min-1], 165 [b.min-1] and 180 [b.min-1],respectively. The musical cadence was electronically controlled by ametronome (Korg, MA-30, Tokyo, Japan) connected to a sound sys-tem. Whenever necessary, the evaluators gave verbal and/or visualcues for subjects to follow the appropriate exercise cadence andaccomplish the number of repetitions asked. All subjects completedthe protocol’s five bouts. The water temperature was 30ºC and therelative humidity was 75 [%].Data CollectionThe protocol was videotaped independently in the frontal plane witha pair of cameras providing a dual projection from both underwater(GR-SXM25 SVHS, JVC, Yokoama, Japan) and above (GR-SX1SVHS, JVC, Yokoama, Japan) the water surface as reported elsewhere(Oliveira et al., 2010; in press). The study included kinematical analy-sis of the full exercise cycle (Ariel Performance Analysis System, ArielDynamics Inc., USA) through a VCR (Panasonic, AG 7355, Japan)with a sampling rate of 50 [Hz]. Zatsiorsky’s model adapted by deLeva (1996) was used, dividing the trunk in two articulated segmentsand including an overall number of nineteen body landmarks to bedigitized in each frame. To create a single image of dual projection,as described previously (Barbosa et al., 2010b) the independent dig-italization from both cameras was reconstructed with the help of acalibration object (1.50 x 0.85 m; 6 control points) and a 2D-DLTalgorithm (Abdel-Aziz and Karara, 1971). For the analysis of thecurve of the center of mass kinematics, a filter with a 5 [Hz] cut-offfrequency was used and for the segmental kinematics 9 [Hz] was used.A double-passage filtering for the signal processing was performed.Assessed were the: (i) cycle period (P, s); (ii) range of motion (∆φ, º)of the thigh-trunk, lower leg-thigh, upper arm-arm from left and(Continued to page 13)13right sides and; angular velocity (ω, º/s) thigh-trunk, lower leg-thigh,upper arm-arm from both sides.Statistical ProceduresThe normality of the distribution was assessed with the Shapiro-Wilktest. For descriptive analysis, mean plus one standard deviation werecomputed as central tendency and dispersion measures, respectively.For each relationship, the mathematical model with the best good-of-fit adjustment and the lowest standard error of estimation wasadopted. All relationships presented a better adjustment when linearregressions were computed. So, linear regression models were used todescribe the relationships between musical cadence and selected kine-matical variables, as well as, its coefficients of determination. As ruleof thumb, for qualitative and effect size assessments, it was definedthat the relationship was: (i) very weak if R2 < 0.04; weak if 0.04 ≤R2 < 0.16; moderate if 0.16 ≤ R2 < 0.49; high if 0.49 ≤ R2 < 0.81 and;very high of 0.81 ≤ R2 < 1.0. The level of statistical significance wasset at P ≤ 0.05.Results and DisscussionThere was a significant, negative and very high relationship betweenP and musical cadence (R2 = 0.77; P < 0.01). This means that increas-ing cadences imposed a decrease in the absolute duration of a fullexercise. Decreasing time to perform a full exercise can be obtained:(i) decreasing the joint’s ∆φ and maintaining the ω or; (ii) maintain-ing the joint’s ∆φ and increasing the ω or; (iii) combining both. So,it is useful to assess both angular displacements and velocities forupper and lower limbs, in order to make it clear.There was a decrease in the ∆φ (e.g., right side thigh-leg: R2 = 0.286;P = 0.002; left side thigh-leg: R2 = 0.141; P = 0.041; left side upperarm-arm: R2 = 0.135; P = 0.046) with increasing musical cadences.In the same way there was a trend for the increase of the ω withincreasing musical cadence but with no statistical meaning for mostselected variables, except for the right side thigh-trunk (R2 = 0.133;P = 0.047). So, decreasing the cycle period is achieved through a com-bination of decreasing the ∆φ and increasing the ω. Although thecombined kinematical strategy, a partial comparison to analyze themost determinant behavior (i.e., if the decrease of ∆φ or the increasein the ω) reveals that subjects decrease the cycle period mainlydecreasing joint range of motion.ConclusionThe increase of musical cadence imposed a decrease of the cycleperiod and; the cycle period changed the limb’s kinematics, mainlyimposing a ∆φ decrease. As practical implication, instructors shouldchoose musical cadences according to subject’s fitness level, avoidingcadences that impose a significant decrease of the full ∆φ. Plus, theyshould always give verbal and/or visual cues for subjects to performthe exercises through full range of motion, following the selected exer-cise cadence.References6. Abdel-Aziz, Y. & Karara, H. Direct linear transformation from com-parator coordinates into object space coordinates in close-rangephotogametry. Proceedings of the Symposium on Close-Range Pho-togametry. Falls Church, VA: American Society of Photogametry, 1971.7. Barbosa, T.M., Sousa, V., Silva, A.J., Reis, V.M., Marinho, D.A. &Bragada, J.A. Effects of music cadence in the acute physiological adap-tations to head-out aquatic exercises. Journal of Strength and Condi-tioning Research 2010a; 24: 244-250.8. Barbosa, T.M., Silva, A.J., Reis, A., Costa, M.J., Garrido, N., Policarpo,F. & Reis, V.M . Kinematical changes in swimming front Crawl andBreaststroke with the AquaTrainer® snorkel. European Journal ofApplied Physiology 2010b; 109: 1155-629. De Leva, P. Adjustments to Zatsiorsky-Seluyanov’s segment inertiaparameters. Journal of Biomechanics 1996; 29(9): 1223-1230.10. Kinder, T., & See, J. Aqua Aerobics – A Scientific Approach. Dubuque,IA: Eddie Bowers Publishing, 1992.11. Oliveira C, Teixeira G, Costa MJ, Marinho, D.A., Silva, A.J. & Barbosa,T.M. Kinematical characterization of a basic head-out aquatic exerciseduring an incremental protocol. In Kjendlie PL, Stallman RK, Cabri J,eds. Biomechanics and Medicine in Swimming XI. Oslo: NorwegianSchool of Sport Sciences, 2010: 137-3912. Oliveira, C., Teixeira, G., Costa, M.J., Marinho, D.A., Silva, A.J. &Barbosa, T.M. Relationship between head-out aquatic exercise kinemat-ics and musical cadence: analysis of the side kick. InternationalSportMed Journal (in press).13. Sanders, M. YMCAWater Fitness for Health. Human Kinetics, Cham-paign, IL, 2000.(Continued from page 12)

Head-out aquatic exercise “sailer’s jigs” kinematics at increasing musical cadence

1 2 HEAD-OUT AQUATIC EXERCISE “SAILOR’S JIGS” KINEMATICS  AT INCREASING  MUSICAL CADENCE Genoveva Teixeira, Cristiana Oliveira, Mário J Costa, Daniel A Marinho, António J Silva, Tiago M Barbosa  Polytechnic Institute of Bragança, Bragança, Portugal Research Centre in Sports, Health and Human Development, Vila Real, Bragança 1 2 1. Introduction Head-out aquatic classes are most of the time full with dozens of subjects, having instructors a greater challenge to maintain all of them synchronized. Instructors use on regular basis the music cadence for such purpose. Added to that, music’s melody and cadence are a way to motivate subjects, achieving a given intensity of exertion (Kinder and See, 1992).  The aim of this study was to analyze the relationships between “Sailor’s jigs” kinematic and increasing music cadence. It was hypothesized that increasing musical cadence will decrease the cycle period and, therefore, the segmental range of motion.  2. Methods Subjects. Six young women, non-pregnant, clinically healthy and physically active, holding a graduation degree in Sports Sciences and with at least one year of experience conducting head-out aquatic classes, volunteered to participate in this study (23.50   3.51 years-old; 57.17  4.07 kg of body mass; 1.66   0.06 m of height; 20.60  0.55 kg/m2 of body mass index; 270.00   80.50 minutes of aquatic fitness classes per week). Subjects reported no previous history of orthopedic or muscle-skeletal injuries in the previous six months.  1 2 Procedures. Each subject performed a basic head-out aquatic exercise entitled “Sailor’s jigs”. The exercise was performed using the ‘‘water tempo’’ according to the standard recommendations from the technical literature (Kinder and See, 1992) that was already reported in some scientific papers as well (e.g., Barbosa et al., 2010a).  The protocol consisted of five sets of 16 full repetitions of the “Sailor’s jigs” exercise, at the “water tempo”, immersed to the xiphoid process (i.e., breast). The bouts intensities were 80 [%], 90 [%], 100 [%], 110 [%] and 120 [%] of the cadence reported by Barbosa et al. (2010a) to achieve a 4 [mmol.l-1] of blood lactate, representing 120 [b.min-1], 135 [b.min-1], 150 [b.min-1], 165 [b.min-1] and 180 [b.min-1], respectively. The musical cadence was electronically controlled by a metronome (Korg, MA-30, Tokyo, Japan) connected to a sound system.  Whenever necessary, the evaluators gave verbal and/or visual cues for subjects to follow the appropriate exercise cadence and accomplish the number of repetitions asked. All subjects completed the protocol’s five bouts. The water temperature was 30ºC and the relative humidity was 75 [%]. 1 2 Data Collection. The protocol was videotaped independently in frontal plane with a pair of cameras providing a dual projection from both underwater (GR-SXM25 SVHS, JVC, Yokoama, Japan) and above (GR-SX1 SVHS, JVC, Yokoama, Japan) the water surface as reported elsewhere (Oliveira et al., 2010; in press). The study included kinematical analysis of the full exercise cycle (Ariel Performance Analysis System, Ariel Dynamics Inc., USA) through a VCR (Panasonic, AG 7355, Japan) with a sampling rate of 50 [Hz]. Zatsiorsky’s model adapted by de Leva (1996) was used, dividing the trunk in two articulated segments and including an overall number of nineteen body landmarks to be digitized in each frame.  1 2 Data Collection (cont). To create a single image of dual projection, as described previously (Barbosa et al., 2010b) the independent digitalization from both cameras was reconstructed with the help of a calibration object (1.50 x 0.85 m; 6 control points) and a 2D-DLT algorithm (Abdel-Aziz and Karara, 1971). For the analysis of the curve of the center of mass kinematics, a filter with a 5 [Hz] cut-off frequency was used and for the segmental kinematics 9 [Hz] was used. A double-passage filtering for the signal processing was performed. It was assessed the: (i) cycle period (P, s); (ii) range of motion (∆ , º) of the thigh-trunk, lower leg-thigh, upper arm-arm from left and right sides and; angular velocity ( , º/s) thigh-trunk, lower leg-thigh, upper arm-arm from both sides 1 2 Statistical Procedures. The normality of the distributions was assessed with the Shapiro-Wilk test. For descriptive analysis, mean plus one standard deviation were computed as central tendency and dispersion measures, respectively. For each relationship, the mathematical model with the best good-of-fit adjustment and the lowest standard error of the estimation was adopted. All relationships presented a better adjustment when linear regressions were computed. So, linear regression models were used to describe the relationships between musical cadence and selected kinematical variables, as well as, its coefficients of determination. As rule of thumb, for qualitative and effect size assessments, it was defined that the relationship was: (i) very weak if R2 < 0.04; weak if 0.04 ≤ R2 < 0.16; moderate if 0.16 ≤ R2 < 0.49; high if 0.49 ≤ R2 < 0.81 and; very high of 0.81 ≤ R2 < 1.0. The level of statistical significance was set at P  0.05.  1 2 3. Results There was a significant, negative and very high relationship between P and musical cadence (R2 = 0.77; P < 0.01). This means that increasing cadences imposed a decrease in the absolute duration of a full exercise.   Decreasing time to perform a full exercise can be obtained: (i) decreasing the joint’s ∆  and maintaining the  or; (ii) maintaining the joint’s ∆  and increasing the  or; (iii) combining both. So, it is useful to assess both angular displacements and velocities for upper and lower limbs, in order to clear it out. 1 2 4. Discussion There was a decrease in the ∆  (e.g., right side thigh-leg: R2 = 0.286; P = 0.002; left side thigh-leg: R2 = 0.141; P = 0.041; left side upper arm-arm: R2 = 0.135; P = 0.046) with increasing musical cadences.   In the same way there was a trend for the increase of the  with increasing musical cadence but with no statistical meaning for most selected variables, except for the right side thigh-trunk (R2 = 0.133; P = 0.047).  The decrease of the cycle period is achieved through a combined way, decreasing the ∆  and increasing the .   Although the combined kinematical strategy, a partial comparison to analyze the most determinant behavior (i.e., if the decrease of ∆  or the increase in the ) reveals that subjects decrease the cycle period mainly decreasing the joints range of motions. 1 2 5. Conclusions The increase of musical cadence imposed a decrease of the cycle period and; the cycle period changed the limb’s kinematics, mainly imposing a ∆  decrease.   As practical implication, instructors should choose musical cadences according to subject’s fitness level, avoiding cadences that impose a significant decrease of the full ∆ . Plus, they should always give verbal and/or visual cues for subjects perform the exercises in the full range of motions, following the selected exercise cadence. 6. References Abdel-Aziz, Y. & Karara, H. Direct linear transformation from comparator coordinates into object space coordinates in close-range photogametry. Proceedings of the Symposium on Close-Range Photogametry. Falls Church, VA: American Society of Photogametry, 1971.  Barbosa, T.M., Sousa, V., Silva, A.J., Reis, V.M., Marinho, D.A. & Bragada, J.A. Effects of music cadence in the acute physiological adaptations to head-out aquatic exercises. Journal of Strength and Conditioning Research 2010a; 24: 244-250.   Barbosa, T.M., Silva, A.J., Reis, A., Costa, M.J., Garrido, N., Policarpo, F. & Reis, V.M . Kinematical changes in swimming front Crawl and Breaststroke with the AquaTrainer® snorkel. European Journal of Applied Physiology 2010b; 109: 1155-62  De Leva, P. Adjustments to Zatsiorsky-Seluyanov’s segment inertia parameters. Journal of Biomechanics 1996; 29(9): 1223-1230. Kinder, T., & See, J. Aqua Aerobics – A Scientific Approach. Dubuque, IA: Eddie Bowers Publishing, 1992.  Oliveira C, Teixeira G, Costa MJ, Marinho, D.A., Silva, A.J. & Barbosa, T.M. Kinematical characterization of a basic head-out aquatic exercise during an incremental protocol. In Kjendlie PL, Stallman RK, Cabri J, eds. Biomechanics and Medicine in Swimming XI. Oslo: Norwegian School of Sport Sciences, 2010: 137-39    Oliveira, C., Teixeira, G., Costa, M.J., Marinho, D.A., Silva, A.J. & Barbosa, T.M. Relationship between head-out aquatic exercise kinematics and musical cadence: analysis of the side kick. International SportMed Journal (in press).  Sanders, M. YMCA Water Fitness for Health. Human Kinetics, Champaign, IL, 2000. 

Head-out aquatic exercise “sailor’s jigs” kinematics at increasing musical cadence

Oliveira, Cristiana

Costa, Mário

Marinho, Daniel

Silva, António

Repositório Institucional do Instituto Politécnico da Guarda

English

Head-out aquatic exercise “sailor’s jigs” kinematics at increasing musical cadence.

http://bibliotecadigital.ipb.pt/bitstream/10198/6988/3/poster%20IAFC%20AEA%202011%20-%20sailor%27s%20jigs%20kinematics.pdf

Head-out aquatic exercise “sailor’s jigs” kinematics at increasing musical cadence

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Biblioteca Digital do IPB

Repositório Institucional do Instituto Politécnico da Guarda