An Integrated Analysis of Leg Length Differences and the Effect of Correctional Techniques on Stroke Mechanics and Performance Indicators in Competitive Cyclists
DOI:
https://doi.org/10.17140/SEMOJ-1-103Keywords:
Leg length discrepancy, mechanical angles at the hip, knee and ankle, Torque, vastuslateralis Electromyography (EMG)Abstract
Leg length discrepancy amongst the general population is relatively common, increasing susceptibility to a range of injuries potentially transferable to endurance cyclists. While the effects of such conditions are widely reported for the general population, little is known regard-ing a repetitive and constrained activity such as cycling. Therefore, the purpose of this study was to assess pedal mechanical asymmetries of trained cyclists with mild leg length discrepancies and the subsequent effects of compensatory strategies (crank length and cleat wedge) on physiological measures of gross efficiency. Participants completed three 15 min trials at a sub maximal intensity for each condition in a single blind (participants) and balanced order with 15 min recovery between conditions. Torque, vastuslateralis Electromyography (EMG), mechanical angles at the hip, knee and ankle, of both left and right sides were recorded along with expired air analysis and heart rate in order to calculate changes in gross efficiency. The main findings show that participants with 5.4 ± 2.9 mm differences in leg lengths showed small asymmetries in mechanical angles, torque production and muscle activity for which compensatory interventions made positive small changes. Interestingly, these changes resulted in a negative effect on gross efficiency, which would require an adaptation period to remedy any neuromuscular compensatory adaptations. Therefore, cyclists recognized as having leg length discrepancies are recommended to use compensatory interventions such as orthosis, rather than crank length modifications, and that a period of gradual adaptation period be allocated.
References
Gurney B. Leg length discrepancy. Gait & posture. 2002; 15(2): 195-206.
Reid D, Smith B. Leg length inequality: a review of etiol-ogy and management. Physiotherapy Canada. 1984; 36(4): 177- 182.
Subotnick S. Limb length discrepancies of the lower extremity (the short leg syndrome). The Journal of orthopaedic and sports physical therapy. 1981; 3(1): 11. doi: 10.2519/jospt.1981.3.1.11
Woerman A, Binder-Macleod S. Leg length discrepancy as-sessment: accuracv and precision in five clinical methods of evaluation*. The Journal of orthopaedic and sports physical therapy. 1984; 5(5): 230. doi: 10.2519/jospt.1984.5.5.230
McCaw ST, Bates BT. Biomechanical implications of mild leg length inequality. British journal of sports medicine. 1991; 25(1): 10-13. doi: 0.1136/bjsm.25.1.10
Giles L, Taylor J. Low-back pain associated with leg length inequality. Spine. 1981; 6(5): 510-521.
Brunet ME, Cook SD, Brinker M, Dickinson J. A survey of running injuries in 1505 competitive and recreational runners. The Journal of sports medicine and physical fitness. 1990; 30(3): 307.
Farrell KC, Reisinger KD, Tillman MD. Force and repeti-tion in cycling: possible implications for iliotibial band friction syndrome. The Knee. 2003; 10(1): 103-109. doi: http://dx.doi. org/10.1016/S0968-0160(02)00090-X
Kujala U, Friberg O, Aalto T, Kvist M, Österman K. Lower limb asymmetry and patellofemoral joint incongruence in the etiology of knee exertion injuries in athletes. International jour-nal of sports medicine. 1987; 8(03): 214-220. doi: 10.1055/s-2008-1025658
Goel A. Meralgia paresthetica secondary to limb length discrepancy: case report. Archives of Physical Medicine and Rehabilitation. 1999; 80(3): 348-349. doi: http://dx.doi. org/10.1016/S0003-9993(99)90151-X
Holmes J, Pruitt A, Whalen N. Lower extremity overuse in bicycling. Clinics in sports medicine. 1994; 13(1): 187.
Wilber C, Holland G, Madison R, Loy S. An epidemiological analysis of overuse injuries among recreational cyclists. Inter-national journal of sports medicine. 1995; 16(03): 201-206. doi: 10.1055/s-2007-972992
Hogg S. Medical Assistance The Five Most Common Cy-cling Injuries. Paper presented at the Bicycling Australia. 2013.
Mahar R, Kirby R, MacLeod D. Simulated leg-length dis-crepancy: its effect on mean center-of-pressure position and pos-tural sway. Arch Phys Med Rehabil. 1985; 66(12): 822-824.
Cahalan T, King L, Chao E. Symmetry of the vertical ground reaction force in normals. Paper presented at the Proceedings of the European Symposium on Clinical Gait Analysis, Zurich, Switzerland ed Zurich, Switzerland. 1992.
Bhave A, Paley D, Herzenberg JE. Improvement in Gait Pa-rameters After Lengthening for the Treatment of Limb-Length Discrepancy*. The Journal of Bone & Joint Surgery. 1999; 81(4): 529-534.
Kaufman K, Miller L, Sutherland D. Gait asymmetry in pa-tients with limb-length inequality. Journal of Pediatric Ortho-paedics. 1996; 16(2): 144-150.
Too D, Landwer GE. The effect of pedal crank arm length on joint angle and power production in upright cycle ergom-etry. Journal of sports sciences. 2000; 18(3): 153-161. doi: 10.1080/026404100365054
Bini MR, Hume PA, Croft JL. Effects of bicycle saddle height on knee injury risk and cycling performance. Sports medi-cine. 2011; 41(6): 463-476. doi: 10.2165/11588740-000000000- 00000
Peveler WW, Pounders JD, Bishop PA. Effects of saddle height on anaerobic power production in cycling. The Journal of Strength & Conditioning Research. 2007; 21(4): 1023-1027. doi: 10.1519/JSC.0b013e3181d09e60
Inbar O, Dotan R, Trosul T, Dvir Z. The effect of bicycle crank-length variation upon power performance. Ergonomics. 1983; 26(12): 1139-1146. doi: 10.1080/00140138308963449
Macdermid PW, Edwards AM. Influence of crank length on cycle ergometry performance of well-trained female cross-coun-try mountain bike athletes. European Journal of Applied Physi-ology. 2010; 108(1): 177-182. doi: 10.1007/s00421-009-1197-0
Carpes FP, Rossato M, Faria I, Bolli Mota C. Bilateral ped-aling asymmetry during a simulated 40-km cycling time-trial. Journal of Sports Medicine and Physical Fitness. 2007; 47(1): 51.
Smak W, Neptune RR, Hull ML. The influence of pedaling rate on bilateral asymmetry in cycling. Journal of biomechan-ics. 1999; 32(9): 899-906. doi: http://dx.doi.org/10.1016/S0021- 9290(99)00090-1
Marfell-Jones M. Kinanthropometric assessment. Guidelines for athlete assessment in New Zealand Sport. Sport Science New Zealand: Wellington, New Zealand. 1991.
Lucia A, Hoyos J, Perez M, Chicharro JL. Heart rate and performance parameters in elite cyclists: a longitudinal study. Medicine and Science in Sports and Exercise. 2000; 32(10): 1777-1782.
Lucía A, Hoyos J, Chicharro JL. Physiology of professional road cycling. Sports medicine. 2001; 31(5): 325-337.
Rouffet DM, Hautier CA. EMG normalization to study mus-cle activation in cycling. Journal of Electromyography and Ki-nesiology. 2008; 18(5), 866-878. doi: http://dx.doi.org/10.1016/j. jelekin.2007.03.008
Wooles AKP, Palfreeman R. British cycling test methods manual. version 1.6. GB Cycling. 2003.
Neptune RR, Herzog W. Adaptation of muscle coordination to altered task mechanics during steady-state cycling. Jour-nal of biomechanics. 2000; 33(2): 165-172. doi: http://dx.doi. org/10.1016/S0021-9290(99)00149-9
Hug F, Dorel S. Electromyographic analysis of pedal-ing: A review. Journal of Electromyography and Kinesiol-ogy. 2009; 19(2): 182-198. doi: http://dx.doi.org/10.1016/j. jelekin.2007.10.010
So RC, Ng JKF, Ng GY. Muscle recruitment pattern in cy-cling: a review. Physical Therapy in Sport. 2005; 6(2): 89-96. doi: http://dx.doi.org/10.1016/j.ptsp.2005.02.004
McHugh MP, Tyler TF, Greenberg SC, Gleim GW. Differ-ences in activation patterns between eccentric and concentric quadriceps contractions. Journal of sports sciences. 2002; 20(2): 83-91. doi: 10.1080/026404102317200792
Wong YM, Ng GY. Surface electrode placement affects the EMG recordings of the quadriceps muscles. Physical Therapy in Sport. 2006; 7(3): 122-127. doi: 10.1016/j.ptsp.2006.03.006
Fukunaga T, Ichinose Y, Ito M, Kawakami Y, Fukashiro S. Determination of fascicle length and pennation in a con-tracting human muscle in vivo. Journal of applied physiology. 1997; 82(1): 354-358.
Moseley L, Jeukendrup AE. The reliability of cycling ef-ficiency. Medicine and science in sports and exercise. 2001; 33(4): 621-627.
Hopkins WG, Hewson DJ. Variability of competitive perfor-mance of distance runners. Medicine and science in sports and exercise. 2001; 33(9): 1588-1592.
Rhea MR. Determining the magnitude of treatment effects in strength training research through the use of the effect size. Journal of Strength and Conditioning Research. 2004; 18(4): 918-920.
Cohen J. A power primer. 2003. doi: http://dx.doi. org/10.1037/0033-2909.112.1.155
Faria ICPR. The physiology and biomechanics of cycling. New York: Wiley. 1978.
Chavarren J, Calbet JAL. Cycling efficiency and pedalling frequency in road cyclists. European Journal of Applied Physi-ology and Occupational Physiology. 1999; 80(6): 555-563. doi: 10.1007/s004210050634
Ericson M. On the biomechanics of cycling. A study of joint and muscle load during exercise on the bicycle ergometer. Scan-dinavian journal of rehabilitation medicine. 1985; (Supp16): 1-43.
Goel A, Loudon J, Nazare A, Rondinelli R, Hassanein K. Joint moments in minor limb length discrepancy: a pilot study. American journal of orthopedics (Belle Mead, NJ). 1997; 26(12): 852.
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