Strength rations and strength in German Elite-Para-Badminton-players (Standing Classes and Wheelchair Classes)
Felder, H 1, Fröhlich, M.2 & Geise, F.1 – Olympic Training Center, Saarbruecken-Germany1 | University Kaiserslautern - Institute for Sport Science , Kaiserslautern-Germany2
Introduction Since in Badminton / Para-Badminton the entire body (bilaterally and unilaterally) is integrated in the movement pattern, it is of major interest to examine how strength values and ratios are represented in competitive athletes in terms of sports-specific balances or imbalances. Upper and lower body strength and endurance, speed, anaerobic power and trunk muscle function have been pointed out as important factors to be successful in Badminton - and in Para-Badminton as well - competition.
Knee flexion D in N Knee flexion ND in N Knee extension D in N Knee extension ND in N Hip abduction D in N Hip abduction ND in N Hip adduction D in N Hip adduction ND in N Arm flexion D in N Arm flexion ND in N
Regarding trunk muscle function, improving trunk strength and endurance would allow Badminton practitioners to increase their ability to generate and maintain force throughout a match. With the announcement that ParaBadminton will be one of the 22 sports held during the Paralympic Figure 2: Trunk extension / flexion, Trunk lateral flexion, Trunk rotation Games in Tokyo 2020 there is a Following questions should be answered in this study major interest to evaluate some biomechanics for - What are the maximum isometric strength values performance enhancement as well as for injury of the German Para-Badminton national team? prevention in Para-Badminton. - Is there a correlation between strength values/ Strength and trunk instability due to impairments, ratios and classification classes? disabilities and handicaps can have adverse effects on posture, function and movement. An extreme - What are the strength ratios between the dominant strength difference between agonist and antagonist, and non-dominant body side as well as between particularly in the shoulder muscle group, goes along the agonists and antagonists? with an increased injury rate (Ellenbecker, 1991). Methods Data aquisitation took place in the Laboratory of Biomechanics at the Olympic Training Centre RhinelandPalatinate/Saarland, Germany. 22 Athletes (male and female) of the national Para-Badminton Team participated in this study.
Total sample n = 22 221.9 ±72.6 216.2 ±71.5 525.1 ±190.6 457.4 ±184.2 1086.4 ±323.7 953 ±342.7 1345.1 ±395.3 1241.8 ±334.1 336.4 ±116.5 256.2 ±98.2
WH 1 n=3
WH 2 n=3
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-
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SL 3 n=2
SL 4 n = 11
SU 5 n=3
198.2 ±45.7 172.2 ±21.7 566.2 ±38.8 309.9 ±2.2 1002.4 ±37.3 882.6 ±55.2 1617.6 ±114.8 1421 ±101.5 381.5 ±5.4 -
243.9 ±65.6 235.7 ±77.7 484.7 ±186.4 451.6 ±165.1 1009.7 ±233.8 868.9 ±226.3 1291.6 ±411.1 1170.9 ±367.8 358.9 ±117.8 274.4 ±85.6
164.6 ±92.9 174 ±35.2 649.5 ±254 577.3 ±273.1 1423.6 ±549.2 1308.5 ±624.4 1359.4 ±162.6 1382.4 ±257.1 382.8 ±82.5 131.7
WH2 and SU5 class were stronger in the flexion movement to the racquet side. Conclusion
Regarding the results of the present study it was shown that para-badminton player of each class do have muscle imbalances between the dominant and non-dominant side as well as between the agonist and antagonist musculature. Especially the trunk has a great influence on 159.3 354.2 performance of the upper and lower ±75.6 ±71.6 156.5 330.9 limbs and as well the injury preven±44.8 ±102.4 tion (Kibler et al., 2006). There has Arm extension 298.2 254.5 331.1 303.8 287.2 354.9 to be a good foundation of trunk D in N ±72.1 ±71.2 ±65 ±19.5 ±70 ±109.6 muscle strength to build strength Arm extension 247.1 303.9 325.1 136.7 243 109.7 ND in N ±94 ±104.7 ±93.4 ±0.9 ±75.7 in the other body segments. Internal 641.7 598.4 697.4 618.1 670.2 550.1 • Because of the present study, shoulder ±191.3 ±158.8 ±445.3 ±29.5 ±121.7 ±350.9 rotation D in N general strength values are now Internal 578.2 642.5 678.2 573.5 540 557.4 available for all para-badminton shoulder ±191.3 ±152.1 ±413.4 ±199.6 ±164.6 ±69.6 rotation ND in N relevant muscles/muscle groups External 633.3 552.3 783.4 609.4 600.3 674.6 shoulder ±183 ±121.4 ±35.7 ±42 ±207.8 ±244.5 and serve as strength training rotation D in N orientation values and to preExternal 572.3 536.5 792.9 420.4 581.1 444.6 shoulder ±179.9 ±81.2 ±62.7 ±46.9 ±190 ±112.6 vent injuries following muscle rotation ND in N imbalances. Trunk flexion 372.2 217.2 484.8 507.6 333.4 466.2 in N ±145.7 ±132.8 ±188.8 ±65.5 ±99 ±153.1 • It has been shown that the trunk Trunk 875.6 382.1 866.8 1035.1 961.8 955.9 extension in N ±412 ±282.8 ±357 ±183.4 ±459 ±251.2 musculature plays a key role. Trunk lateral 564.1 401 537.4 659.3 579.9 632.4 This applies not only to prevenflexion D in N ±234.6 ±126.9 ±231.9 ±25.6 ±281.1 ±232.3 Trunk lateral 516.1 361.3 455.8 603.9 557.9 519.3 tive considerations, but also badflexion ND in N ±201.2 ±111.3 ±238.4 ±138.9 ±189.7 ±327.6 minton-specific movements. Trunk rotation 443.2 255.1 391.9 432 493.4 506.4 D in N ±152.6 ±31.4 ±17.5 ±100.4 ±166.2 ±151.8 • Agonist-antagonist comparison Trunk rotation 444.4 306.4 364.7 399.7 498 495.5 showed high significant diffeND in N ±169.7 ±175.3 ±21.3 ±192.6 ±192.4 ±87.9 Cervical spine 194 156 170.4 158.6 216.4 196.2 rences between the216.4 trunk flexiCervical spine 194 170.4 158.6 196.2 flexion in N ±50.3 ±30.7 ±21.1 ±41.2 ±58.9 ±22.7 156 in N 263.6 ±50.3 332.8 ±30.7 ±21.1 ±41.2extension ±58.9 muscles ±22.7 on and trunk Cervical spine 276.9 188.1 356.8 flexion 279.2 276.9 ±34.6 188.1 356.8 279.2 263.6 332.8 extension in N ±78.8 ±109.5 ±61.2 Cervical ±35.5 spine±64.3 (p = 0.000, 0.51:1) ±78.8 236.9 ±109.5 ±61.2 ±35.5 ±64.3 ±34.6 Cervical spine 205 144.5 212.4 extension 223.3 in N207.4 lateral flexion ±46.5 ±49.7 ±34 ±24.1 spine±45.2 ±53.7 144.5 Cervical 205 207.4 236.9 • 212.4 Dominant223.3 to non-dominant comD in N lateral flexion ±46.5 ±49.7 ±34 ±24.1 ±45.2 ±53.7 parison showed no signifi cant Cervical spine 203.4 119 177.8 D in 237.3 219.5 232 N lateral flexion ±57.1 ±13.7 ±78 ±25.7 ±45.2 ±44.2 differences between219.5 trunk lateral Cervical spine 203.4 119 177.8 237.3 232 ND in N flexion 13560 ±57.1 14648.7 ±13.7 ±78 ±45.2 1.04:1). ±44.2 flexion and±25.7 rotation (1.12:1; Total strength in 11893 5372.6 8312.2 lateral 13742.9 N N ±4011.7 ±1671.4 ±1268.8ND in ±962.6 ±2982.7 ±2556.5 • 8312.2 No differences found betTotal strength in 11893 5372.6 13742.9were 13560 14648.7 N ±4011.7 ±1671.4 ±1268.8 ±2982.7 ±2556.5 D = Dominant; ND = Non-Dominant ween the±962.6 groups for trunk flexiTable 1: Results of strength measurement in Newton (N) on, extension and lateral flexion. D = Dominant; ND = Non-Dominant Trunk But there was a significant difvene-test a post-hoc test for equal or unequal va ference in trunk rotation to the riances. The significance level in every test was set dominant side (p = 0.024). These atThe p ≤isometric 0.05. strength measurement of the Trunk trunk musculature indicated highly significant differences for the flexion-extension ratio (p = 0.001). As you can see in difference was evident especially Results table 2, the back muscles are 1.7 to 2.8 times stronger than the abdominal between WH1 and SL4 athletes. The isometric strength measurement of the trunk musculature indicated highly musculature. No differences were found in the trunk rotation and lateral flexion In the testing group, 15 players were dominant significant differences for thetrunk ratioin (pstrength = 0.001). performanAs you can see in There isflexion-extension a high difference between both of the body sides. Admittedly, SL3 athletes showed• higher right-handers (73.3%) and 7 dominant left-handers 2, the back are the 1.7 groups, to 2.8 times stronger than the abdominal rotation muscle strength to the non-dominant,table the backhand, side muscles (0.88:1). The ce within especially in trunk flexion (26.7%). The results of lateral the maximal isometric musculature. differences were found in the trunk rotation and lateral flexion comparison between the trunk flexion movement of theNo dominant and nonand extension. dominant side indicate that para-badminton of the WH2 SU5 body class were between both of the sides. Admittedly, SL3 athletes showed higher trunk strength measurement are listedplayer in Table 1. and • Athletes should integrate trunk stabilization traistronger inof thethe flexion movement to the racquet side. rotation muscle Because small sample size, there will be no strength to the non-dominant, the backhand, side (0.88:1). The ningtrunk in every trainingofprogram withand a nonbetween the lateral strength flexion movement the dominant differentiation between genders. Thecomparison values are attention onplayer trunkofrotation fle- were dominant side indicatespecial that para-badminton the WH2and andtrunk SU5 class shown for each tested individual muscle or muscle stronger in the flexion movement to the racquet side. xion muscles. groups from the dominant and non-dominant side. • There should be a follow up of this study with Trunk more participants to get more significant inforThe isometric strength measurement of the trunk mation and to evaluate the training effects. Table 2: Strength ratios of the trunk musculature (D=dominant / ND=non-dominant) musculature indicated highly significant differen• A comparison between strength values and paflexion to Trunk Trunk ces for the flTrunk exion-extension ratiorotation (p = 0.001). Aslateral flexion ra-badminton performance as well as an assigD tomuscles ND you can see extension in table 2, the back are 1.7 toD to ND nment of strength values to injury contribution 2.8Total times stronger abdominal muscula0.52:1*** ±than 0,28 the 1.04:1 ± 0,27 ± 0.36 Table 2: 1.12:1 Strength ratiosshould of the trunk musculature (D=dominant / ND=non-dominant) be done. WH1No differences 0.63:1 ± 0.17 0.97:1 1.11:1 ± 0.06 ture. were found in± 0.38 Trunk rotation Trunk lateral flexion 0.64:1 ± 0.41 1.21:1 ±Trunk 0.21 flexion to theWH2 trunk rotation and lateral1.08:1 fle-± 0.1 D to ND D to ND SL3 between 0.50:1 ± 0.15 0.88:1 1.12:1 ±extension 0.21 xion both of the body si-± 0.87 SL4Admittedly, 0.46:1SL3 ± 0.32athletes1.01:1 0.39 des. sho-± 0.17 Total 1.03:1 ± 0.52:1*** ± 0,28 1.04:1 ± 0,27 1.12:1 ± 0.36 SU5higher trunk 0.49:1 ± rotation 0.1 1.02:1 ± 0.19 1.39:1 ± 0.64 wed muscle WH1 0.63:1 ± 0.17 0.97:1 ± 0.38 1.11:1 ± 0.06 strength to the non-dominant, the WH2 0.64:1 ± 0.41 1.08:1 ± 0.1 1.21:1 ± 0.21 backhand, side (0.88:1). The comSL3 0.50:1 ± 0.15 0.88:1 ± 0.87 1.12:1 ± 0.21 parison between the trunk lateral SL4 0.46:1 ± 0.32 1.01:1 ± 0.17 1.03:1 ± 0.39 flexion movement of the dominant SU5 0.49:1 ± 0.1 1.02:1 ± 0.19 1.39:1 ± 0.64 and non-dominant side indicate that para-badminton player of the Table 2: Strength ratios of the trunk musculature -
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63257 257 25 :,66(16&+$) Figure 1: Classification groups in Para-Badminton used in this study (Short statue group was not point of interest)
Core stability might contribute to Para-Badminton performance as it would facilitate the transmission of forces generated by the lower body to the upper body (and vice-versa) during Badminton techniques , and it would enhance balance control a key factor in coping with disturbances caused by the adversary. By observing para-athletes with and without trunk impairment, classifiers, athletes and stakeholders perceived a significant impact of trunk impairment on performance in wheel- chair activities (Kellie & Barton, 2013, p. 514).
Previous research indicates trunk muscle strength, trunk coordination and trunk range of movement determine: a) trunk position which impacts on force application on the hand rims, b) trunk stability which decreases paradoxical movements, making arm movements and force application more effective and c) trunk movement which determines the range of the push rim that can be used in each push stroke. Therefore, trunk impairment may impact significantly on wheelchair propulsion, especially in high resistance wheeling such as accelerating from standstill (Vanlandewijck et al. p. 339; Chow et al., 2008, p. 271).
Prof. Dr. phil. Michael Fröhlich Fachgebiet Sportwissenschaft Department of Sports Science
The diagnosis device was the „DIERS MYOLINE professional“ which features the option to measure up to 28 muscle groups. Recorded strength was the isometric maximum strength which has a high practical relevance (Turbanski et al., 2008).
During all measurements, the test persons received motivational biofeed-back providing information on duration and strength of the ongoing measurement. With use of the DiCAM software version 2.4.9 (Diers International) all measurements were recorded and saved. The following tests were implemented 9. Trunk flexion 1. Knee flexion 10. Trunk extension 2. Knee extension 11. Trunk lateral flexion 3. Hip abduction 12. Trunk rotation 4. Hip adduction 13. Cervical spine flexion 5. Arm flexion 14. Cervical spine extension 6. Arm extension 7. Internal shoulder rotation 15. Cervical spine lateral flexion 8. External shoulder rotation
The data was used to obtain strength ratios between the dominant and non-dominant body side as well as between agonists and antagonists. The values are tested for significance with of the Wilcoxon-Test. In order to identify differences in strength values between the five classes, there was done a Welch-test and dependent on the result of the Le-
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