Boulder Institute for Sports Medicine

To investigate the effectiveness of a neck strengthening program on the isometric neck strength profile of male rugby union players. Controlled laboratory study. Professional rugby union club. Fifteen professional and 10 semiprofessional rugby union players. The 15 professional players undertook a 5-week neck strengthening intervention, which was performed twice per week, whereas the 10 semiprofessional players acted as the control group. Isometric strength of the neck musculature was tested using a hand-held dynamometer, for flexion (F), extension (E), left-side flexion (LSF), and right-side flexion (RSF). Preintervention and postintervention evaluations were undertaken. No significant between-group differences in isometric neck strength were noted preintervention. A significant main effect for time was observed (P < 0.05), whereby the intervention group increased isometric neck strength in all planes after the 5-week intervention (F preintervention = 334.45 ± 39.31 N vs F postintervention 396.05 ± 75.55 N; E preintervention = 606.19 ± 97.34 vs E postintervention = 733.88 ± 127.16 N; LSF preintervention = 555.56 ± 88.34 N vs LSF postintervention = 657.14 ± 122.99 N; RSF preintervention = 570.00 ± 106.53 N vs RSF postintervention = 668.00 ± 142.18 N). No significant improvement in neck strength was observed for control group participants. The results of the present study indicate that a 5-week neck strengthening program improves isometric neck strength in rugby union players, which may have implications for injury prevention, screening, and rehabilitation. The strengthening program described in the present study may facilitate rehabilitation specialists in the development of neck injury prevention, screening, and rehabilitation protocols.

It is known that bicycle geometry affects performance, although the kinematic effects of certain positions are not well understood. Additionally, there is little standardization of the terminology used to describe the interaction between bicycle geometry and the cyclist's kinematics. PURPOSE: To describe how kinematic descriptors change with time-trial bicycle geometry, saddle design and saddle sitting position. Secondarily; to define kinematic descriptors that bridge the gap between sports scientists and professional bike-fitters. METHODS: Ten trained cyclist volunteered to ride an adjustable geometry cycle ergometer. Sixteen experimental conditions were recorded per subject: two seat tube angles (STA) two saddle designs, two sitting positions (middle and nose) and two trunk angles (TA). Reflective markers were placed over anatomical landmarks. Mean values for the kinematic variables of interest were measured in the sagittal plane via digitization and included: Trunk Angle (TA), Hip Angle (HA), Pelvic Tilt (PT), Knee Angle (KA), Ankle Angle (AA), maximum Dorsi-Flexion (Max Dorsi) and Plantar-Flexion (Min Dorsi). Composite measures were also evaluated: Body Position (BP) (Acromion Process, Greater Trochanter, Bottom Bracket), and Pelvic Position (PP) (Acromion Process, PSIS, Bottom Bracket). RESULTS: Manipulations of TA (Δ18°) yielded kinematic changes of HA (Δ17°), PT (Δ 8.1°), BP (Δ 14.1°) and PP (Δ 14.8°). Increasing STA (Δ 4°) increased HA (Δ 3.5°), decreased PT (Δ 1.5°) BP and PP (Δ 3°, 2.5°). Altering sitting position from the mid-saddle to the nose increased TA(Δ 1.5°), increased hip angle (Δ 2.5°), decreased KA (Δ 2°), BP and PP. (Δ 3.5°, 2.8°). Saddle choice failed to reliable influence changes in any metric, although slight trending was noticed in PT. CONCLUSION: Alterations of TA initiated changes of angles associated with the hip (TA, HA, PT, BP, PP), but did not influence those independent of the hip (KA, AA, Max / Min Dorsi). Changes in STA and saddle sitting position elicited similar responses with the exception that sitting position lead to decreased KA and increased TA. Positions that increased TA tended to increase PT (anterior rotation). No changes were discernable in Max / Min Dorsiflexion during any trial.