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Rodrigo R. Bini, Aline C. Tamborindeguy, and Carlos B. Mota

Context:

It is not clear how noncyclists control joint power and kinematics in different mechanical setups (saddle height, workload, and pedaling cadence). Joint mechanical work contribution and kinematics analysis could improve our comprehension of the coordinative pattern of noncyclists and provide evidence for bicycle setup to prevent injury.

Objective:

To compare joint mechanical work distribution and kinematics at different saddle heights, workloads, and pedaling cadences.

Design:

Quantitative experimental research based on repeated measures.

Setting:

Research laboratory.

patients:

9 healthy male participants 22 to 36 years old without competitive cycling experience.

Intervention:

Cycling on an ergometer in the following setups: 3 saddle heights (reference, 100% of trochanteric height; high, + 3 cm; and low, − 3 cm), 2 pedaling cadences (40 and 70 rpm), and 3 workloads (0, 5, and 10 N of braking force).

Main Outcome Measures:

Joint kinematics, joint mechanical work, and mechanical work contribution of the joints.

Results:

There was an increased contribution of the ankle joint (P = .04) to the total mechanical work with increasing saddle height (from low to high) and pedaling cadence (from 40 to 70 rpm, P < .01). Knee work contribution increased when saddle height was changed from high to low (P < .01). Ankle-, knee-, and hip-joint kinematics were affected by saddle height changes (P < .01).

Conclusions:

At the high saddle position it could be inferred that the ankle joint compensated for the reduced knee-joint work contribution, which was probably effective for minimizing soft-tissue damage in the knee joint (eg, anterior cruciate ligament and patellofemoral cartilage). The increase in ankle work contribution and changes in joint kinematics associated with changes in pedaling cadence have been suggested to indicate poor pedaling-movement skill.

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Marcus P. Tartaruga, Carlos B. Mota, Leonardo A. Peyré-Tartaruga, and Jeanick Brisswalter

Purpose:

To identify the effect of allometric scaling on the relationship between running efficiency (R Eff) and middle-distancerunning performance according to performance level.

Methods:

Thirteen male recreational middle-distance runners (mean ± SD age 33.3 ± 8.4 y, body mass 76.4 ± 8.6 kg, maximal oxygen uptake [VO2max] 52.8 ± 4.6 mL · kg−1 · min−1; G1) and 13 male high-level middle-distance runners (age 25.5 ± 4.2 y, body mass 62.8 ± 2.7 kg, VO2max 70.4 ± 1.9 mL · kg−1 · min−1; G2) performed a continuous incremental test to volitional exhaustion to determine VO2max and a 6-min submaximal running test at 70% of VO2max to assess R Eff.

Results:

Significant correlation between R Eff and performance were found for both groups; however, the strongest correlations were observed in recreational runners, especially when using the allometric exponent (respectively for G1, nonallometric vs allometric scaling: r = .80 vs r = .86; and for G2, nonallometric vs allometric scaling: r = .55 vs r = .50).

Conclusion:

These results indicate that an allometric normalization may improve endurance-performance prediction from R Eff values in recreational, but not in elite, runners.

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Fábio J. Lanferdini, Rodrigo R. Bini, Pedro Figueiredo, Fernando Diefenthaeler, Carlos B. Mota, Anton Arndt, and Marco A. Vaz

Purpose:

To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (POVT2) compared with cycling at their maximal power output (POMAX).

Methods:

Twenty athletes performed an incremental cycling test to determine their power output (POMAX and POVT2; first session), and pedal forces, muscle activation, muscle–tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in POMAX and POVT2. Athletes were assigned to 2 clusters based on the behavior of outcome variables at POVT2 and POMAX using cluster analysis.

Results:

Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle–tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at POVT2 vs POMAX, cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length.

Conclusions:

Increases in power output lead to greater variations in knee angle, muscle–tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.