Article

The effect of saddle position on maximal power output and moment generating capacity of lower limb muscles during isokinetic cycling.

Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, K. U. Leuven, Leuven, Belgium.
Journal of applied biomechanics (Impact Factor: 0.9). 02/2011; 27(1):1-7.
Source: PubMed

ABSTRACT Saddle position affects mechanical variables during submaximal cycling, but little is known about its effect on mechanical performance during maximal cycling. Therefore, this study relates saddle position to experimentally obtained maximal power output and theoretically calculated moment generating capacity of hip, knee and ankle muscles during isokinetic cycling. Ten subjects performed maximal cycling efforts (5 s at 100 rpm) at different saddle positions varying ± 2 cm around the in literature suggested optimal saddle position (109% of inner leg length), during which crank torque and maximal power output were determined. In a subgroup of 5 subjects, lower limb kinematics were additionally recorded during submaximal cycling at the different saddle positions. A decrease in maximal power output was found for lower saddle positions. Recorded changes in knee kinematics resulted in a decrease in moment generating capacity of biceps femoris, rectus femoris and vastus intermedius at the knee. No differences in muscle moment generating capacity were found at hip and ankle. Based on these results we conclude that lower saddle positions are less optimal to generate maximal power output, as it mainly affects knee joint kinematics, compromising mechanical performance of major muscle groups acting at the knee.

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    • "The peak force applied in one cycle in submaximal conditions is more than 5 times higher during running, measured as a ground reaction force (Kyröläinen et al., 1999) than in cycling, measured as a pedal force (Farrell et al., 2003). Also the peak joint moments and power patterns in ankle, knee and hip joints are different during running stance phase than in pedal cycle at steady-state submaximal (Schache et al., 2011; Bini & Diefenthaeler, 2010; Elmer et al., 2011; William et al., 2012) and at sprinting conditions (Bezodis et al., 2012; Martin & Brown, 2009; Vrints et al., 2011; Elmer et al., 2011). The main muscle groups that are involved in cycling and running are the knee extensors and ankle plantar flexors, respectively, but in contrast to cycling, which includes mainly concentric contractions, during running the eccentric muscle actions play an important role (Bijker et al 2002; William et al., 2012). "
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    • "The peak force applied in one cycle in submaximal conditions is more than 5 times higher during running, measured as a ground reaction force (Kyröläinen et al., 1999) than in cycling, measured as a pedal force (Farrell et al., 2003). Also the peak joint moments and power patterns in ankle, knee and hip joints are different during running stance phase than in pedal cycle at steady-state submaximal (Schache et al., 2011; Bini & Diefenthaeler, 2010; Elmer et al., 2011; William et al., 2012) and at sprinting conditions (Bezodis et al., 2012; Martin & Brown, 2009; Vrints et al., 2011; Elmer et al., 2011). The main muscle groups that are involved in cycling and running are the knee extensors and ankle plantar flexors, respectively, but in contrast to cycling, which includes mainly concentric contractions, during running the eccentric muscle actions play an important role (Bijker et al 2002; William et al., 2012). "
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    ABSTRACT: The purpose of this study was to compare the isokinetic muscle performance of lower limbs in middle distance runners and road cyclists. Subjects: 10 competitive Estonian middle distance runners (age 23.8 ± 3.8 yrs., height 181.8 ± 2.8 cm, mass 73.6 ± 7.4kg) and 16 road cyclists (21.1 ± 3.5 yrs., 181.5 ± 5.0cm, 74.8 ± 7.0kg) volunteered in this study. Methods: Isokinetic strength of ankle plantar flexors (A-pf), ankle dorsal flexors (A-df), knee (K) and hip (H) extensors (ex) and flexors (fl) were measured with Humac NORM isokinetic dynamometer in angular speeds 60, 180 and 240 °/s. Isokinetic peak torque (PT), and power (P) values of best repetition and total work (ToW) of 15 repetitions in angular speed 240°/s were expressed as a mean of dominant and non-dominant leg. The absolute and relative isokinetic values were compared between runners and cyclists. Results: The comparison of PT values shows that cyclists have significantly (p<0.05) higher results in A-pf and K-fl in all testing speeds. No significant differences between A-df, K-ex, H-fl and H-ex PT values at any speed were found. Cyclists had also significantly higher P results in A-pf, K-fl and K-ex in all testing speeds and tendency (p=0.08) in H-ex 60°/s. ToW values of A-pf, K-ex and K-fl were significantly higher in cyclists group, but runners had higher values in H-fl. Conclusion: Cyclists have higher isokinetic muscle performance values in A-pf, K-fl, and K-ex and runners have higher total work ability in H-fl. No significant differences in A-df and H-ex performance between cyclists and runners were found. Runners and cyclists have also different power-velocity curves of A-df, H-ex, K-ex and K-fl
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    • "Higher saddle positions (109% of inner leg length or 102% greater than trochanter height) are reported to be more effective for power production (Rankin & Neptune, 2010; Vrints et al., 2011). Lower saddle positions affects knee joint kinematics, compromising mechanical performance of major muscle groups acting at the knee (Vrints et al., 2011). "
    Journal of Human Sport and Exercise 01/2013; 8(Proc2):19-29. DOI:10.4100/jhse.2012.8.Proc2.03
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