Graham Fletcher

Reduced Eccentric Loading of the Knee with the Pose Running Method

PURPOSE The aim of this study was to compare the biomechanical changes during natural heel-toe running with learned midfoot and Pose running. METHODS Twenty heel-toe runners were instructed in midfoot running and a novel running style in which the acromium, greater trochanter, and lateral malleolus are aligned in stance (Pose running). Clinical gait analysis was performed for each running style and the biomechanical variables compared. RESULTS In comparison with midfoot and heel-toe running Pose running was characterized by shorter stride lengths and smaller vertical oscillations of the sacrum and left heel marker. Compared with midfoot and Pose running heel-toe running was characterized by greater magnitudes and loading rates of the vertical impact force. In preparation for initial contact, the knee flexed more in Pose than in heel-toe and midfoot running. The ankle at initial contact was neutral in Pose compared with a dorsiflexed and plantarflexed position in heel-toe and midfoot running, respectively. The knee power absorption and eccentric work were significant lower (P < 0.05) in Pose than in either heel-toe or midfoot running. In contrast, there was a higher power absorption and eccentric work at the ankle in Pose compared with heel-toe and midfoot running. CONCLUSIONS Pose running was associated with shorter stride lengths, smaller vertical oscillations of the sacrum and left heel markers, a neutral ankle joint at initial contact, and lower eccentric work and power absorption at the knee than occurred in either midfoot or heel-toe running. The possibility that such gait differences could be associated with different types and frequencies of running injuries should be evaluated in controlled clinical trails.

Runners do not push off the ground but fall forwards via a gravitational torque

The relationship between the affect and timing of the four forces involved in running (gravity, ground reaction force, muscle force, and potential strain energy) is presented. These forces only increase horizontal acceleration of the centre of mass during stance but not flight. The current hierarchical models of running are critiqued because they do not show gravity, a constant force, in affect during stance. A new gravitational model of running is developed, which shows gravity as the motive force. Gravity is shown to cause a torque as the runners centre of mass moves forward of the support foot. Ground reaction force is not a motive force but operates according to Newtons third law; therefore, the ground can only propel a runner forward in combination with muscle activity. However, leg and hip extensor muscles have consistently proven to be silent during leg extension (mid-terminal stance). Instead, high muscle–tendon forces at terminal stance suggest elastic recoil regains most of the centre of masss height. Therefore, the only external motive force from mid-terminal stance is gravity via a gravitational torque, which causes a horizontal displacement. The aim of this paper is to establish a definitive biomechanical technique (Pose® method) that is easily taught to runners (Romanov, 2002): falling forwards via a gravitational torque while pulling the support foot rapidly from the ground using the hamstring muscles.

Pose® Method Technique Improves Running Performance without Economy Changes

The aim was to investigate the affects of the Pose® method intervention on running technique, on economy and a time-trial runs. A 2 × 2 mixed factorial ANOVA assessed sixteen research variables where group (Heel-toe vs. Pose®) and trial (pre to post changes) was used. Significant interactions were explored using Tukey post hoc tests, which found significance (Pose® runners pre-post test) for stance time (p = 0.001), horizontal displacement of the centre of mass to support foot at 25 ms after impact (p = 0.042), centre of mass displacement during stance (p = 0.001), knee flexion angular velocity during stance (p = 0.005) and during swing to maximum knee flexion (p = 0.043) and stride frequency (p = 0.002). The Pose® groups post-test time-trial (2400 m) was not significant yet they improved by a mean of 24.7 s compared with a 3 s decrease in the heel-toe group. No significant changes pre-post test, were found for an economy run (2400 m) at 3.35 m/s.

Determining key biomechanical performance parameters in novice female rowers using the Rosenberg and Pose techniques during a 1 km ergometer time trial

The link between internal and external forces in rowing and the related kinematics causing stroke length, stroke frequency and boat velocity is presently ambiguous. This study examined these biomechanical parameters using two diverse rowing techniques: Rosenberg and Pose. Ten female novice rowers participated in a pre-and post-test 1 km time trial using a Concept 2 ergometer fitted with load cells at the handle/foot stretchers. Pose rowing was significantly different from Rosenberg rowing in increased stroke frequency per minute (mean ± S. D. 32 ± 1: 37 ± 4) and decreased stroke length (m) (1.3 ± 0.1: 1.1 ± 0.1). Oar handle impulse (N. s) was significantly less in the Pose rowers (266 ± 24: 222 ± 26) while power (W) remained similar (223 ± 26: 222 ± 26). SIMI Motion recorded two-dimensional kinematics. Significantly less trunk extension (°) (-29 ± 1.0: -14 ± 0.5) at the end of the drive phase in Pose rowing may explain the stroke length and stroke frequency significant differences between the two techniques possibly owing to the 18.3% shorter drive time. Practical application centred on the transfer of body weight from the foot stretchers, oar handle and seat in reference to the influence of muscle activity.

Effects of running retraining on biomechanical factors associated with lower limb injury

Injury risk is an important concern for runners; however, limited evidence exists regarding changes to injury risk following running style retraining. Biomechanical factors, such as absolute peak free moment, knee abduction impulse, peak foot eversion and foot eversion excursion, have been shown to predict lower limb injury. The aim of this study was to assess the effects of Pose running retraining on biomechanical factors associated with lower limb running injury. Twenty uninjured recreational runners were pair-matched based on their five km run time performance and randomly assigned to control (n = 10) and intervention (three 2-h Pose running retraining sessions) groups (n = 10). Three dimensional kinetic and kinematic data were collected from all participants running at relative (REL: 1.5 km·h-1 below respiratory compensation point) and absolute (ABS: 4.5 m·s-1) speeds. Biomechanical factors associated with lower limb injury, as well as selected kinematic variables (to aid interpretation), were assessed. Following a six-week, non-coached time-period, all assessments were repeated. No changes to the biomechanical factors associated with lower limb injury examined in this study were observed (P > .05). Intervention group participants (presented as pre- and post-intervention respectively) exhibited an increased foot strike index (REL speed: 21.79-42.66%; ESW = 4.73; P = .012 and ABS speed: 22.38-46.98%; ESW = 2.83; P = .008), reduced take-off distance (REL speed: -0.35 to -0.32 m; ESW = 0.75; P = .012), increased knee flexion at initial contact (REL speed: -14.11 to -18.50°; ESW = -0.88; P = .003), increased ankle dorsiflexion at terminal stance (REL speed: -33.61 to -28.35°; ESW = 1.57; P = .036) and reduced stance time (ABS speed: 0.21-0.19 s; ESW = -0.85; P = .018). Finally, five km run time did not change (22:04-22:19 min; ESW = 0.07; P = .229). It was concluded that following Pose running retraining, retrained participants adopted a running style that was different to their normal style without changing specific, biomechanical factors associated with lower limb injury or compromising performance.

A Case Study of Two National Standard Sprinters Completing a Pose and Traditional Sprint StartTechnique

A Case Study of Two National Standard Sprinters Completing a Pose and Traditional Sprint Start Technique The purpose of this study was to determine the kinematic and kinetic differences between two elite sprinters completing a traditional and Pose sprint start. A traditional start technique teaches driving out of the starting blocks whereas the Pose start teaches pulling the hands from the ground first and then immediately pulling the back foot out of the starting block towards the buttocks. The findings indicated both starts showed maximal starting block force occurred before the hands left the ground, except for the front foot vertical force in the Pose start. Both sprint starts showed a proximal-to-distal lower limb muscle activation for the back leg during the starting block phase. The Pose start had less time when muscles were active during the starting block phase and showed an increased back leg knee angular extension-flexion velocity. Finally, significantly greater horizontal displacement after 1 s was achieved by the Pose start.

Authors' response to “Comments on ‘Runners do not push off but fall forward via a gravitational torque’” (Vol. 6, pp. 434–452)

Brodie and colleagues claim Fp is propulsive when running downhill, but otherwise is not pointing in the direction of the movement of the centre of mass (CoM) in running. First, the resultant force of gravity (Fg) and ground reaction force (GRF) between mid-stance to terminal stance (Figure 1a; using real scaled data at 67% of stance) in running can actually show the resultant force for a male runner at 3.35 m/s does not always point in the intuitive direction of motion of the CoM throughout midto terminal stance (Figure 1b; using real scaled data at 85% of stance). Second, running is similar to a ball on a slope (both have an Fp component of gravity) except that the runner has a positive vertical displacement from mid-stance to terminal stance. Fp is the force that causes the gravitational torque in running, whereas for the ball,