3-D kinematic comparison of treadmill and overground running.

Studies investigating the mechanics of human movement are often conducted using the treadmill. The treadmill is an attractive device for the analysis of human locomotion. Studies comparing overground and treadmill running have analyzed discrete variables, however differences in excursion from footstrike to peak angle and range of motion during stance have yet to be examined. This study aimed to examine the 3-D kinematics of the lower extremities during overground and treadmill locomotion to determine the extent to which the two modalities differ. Twelve participants ran at 4.0m/s in both treadmill and overground conditions. 3-D angular kinematic parameters during the stance phase were collected using an eight camera motion analysis system. Hip, knee and ankle joint kinematics were quantified in the sagittal, coronal and transverse planes, then compared using paired t-tests. Of the parameters analyzed hip flexion at footstrike 12° hip range of motion 17°, peak hip flexion 12.7°, hip transverse plane range of motion 8° peak knee flexion 5° and peak ankle excursion range 6.6°, coronal plane ankle angle at toe-off 6.5° and peak ankle eversion 6.3° were found to be significantly different. These results lead to the conclusion that the mechanics of treadmill locomotion cannot be generalized to overground

The influence of barefoot and barefoot inspired footwear on the kinetics and kinematics of running in comparison to conventional running shoes.

Barefoot running has experienced a resurgence in footwear biomechanics literature, based on the supposition that it serves to reduce the occurrence of overuse injuries in comparison to conventional shoe models. This consensus has lead footwear manufacturers to develop shoes which aim to mimic the mechanics of barefoot locomotion. This study compared the impact kinetics and 3-D joint angular kinematics observed whilst running: barefoot, in conventional cushioned running shoes and in shoes designed to integrate the perceived benefits of barefoot locomotion. The aim of the current investigation was therefore to determine whether differences in impact kinetics exist between the footwear conditions and whether shoes which aim to simulate barefoot movement patterns can closely mimic the 3-D kinematics of barefoot running. Twelve participants ran at 4.0 m.s-1±5% in each footwear condition. Angular joint kinematics from the hip, knee and ankle in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. In addition simultaneous tibial acceleration and ground reaction forces were obtained. Impact parameters and joint kinematics were subsequently compared using repeated measures ANOVAs. The kinematic analysis indicates that in comparison to the conventional and barefoot inspired shoes that running barefoot was associated significantly greater plantar-flexion at footstrike and range of motion to peak dorsiflexion. Furthermore, the kinetic analysis revealed that compared to the conventional footwear impact parameters were significantly greater in the barefoot condition. Therefore this study suggests that barefoot running is associated with impact kinetics linked to an increased risk of overuse injury, when compared to conventional shod running. Furthermore, the mechanics of the shoes which aim to simulate barefoot movement patterns do not appear to closely mimic the kinematics of barefoot locomotion

Impact of harness attachment point on kinetics and kinematics during sled towing.

Resisted sprint training is performed in a horizontal direction, and involves similar muscles, velocities and ranges of motion (ROM) to those of normal sprinting. Generally, sleds are attached to the athletes via a lead (3m) and harness; the most common attachment points are the shoulder or waist. At present, it is not known how the different harness point's impact on the kinematics and kinetics associated with sled towing (ST). The aim of the current investigation was to examine the kinetics and kinematics of shoulder and waist harness attachment points in relation to the acceleration phase of ST. Fourteen trained males completed normal and ST trials, loaded at 10% reduction of sprint velocity. Sagittal plane kinematics from the trunk, hip, knee and ankle were measured, together with stance phase kinetics (third foot-strike). Kinetic and kinematic parameters were compared between harness attachments using one-way repeated measures analysis of variance. The results indicated that various kinetic differences were present between the normal and ST conditions. Significantly greater net horizontal mean force, net horizontal impulses, propulsive mean force and propulsive impulses were measured (p>0.05). Interestingly, the waist harness also led to greater net horizontal impulse when compared to the shoulder attachment (p = 0.000). In kinematic terms, ST conditions significantly increased peak flexion in hip, knee and ankle joints compared to the normal trials (p<0.05). Results highlighted that the shoulder harness had a greater impact on trunk and knee joint kinematics when compared to the waist harness (p<0.05). In summary, waist harnesses appear to be the most suitable attachment point for the acceleration phase of sprinting. Sled towing with these attachments resulted in fewer kinematic alterations and greater net horizontal impulse when compared to the shoulder harness. Future research is necessary, in order to explore the long-term adaptations of these acute changes

Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer

Background: Impairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (&lt;50 years) is rising, there is little data on functional outcomes in this group. Methods: The REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, &lt;50 years of age at time of diagnosis and with documented follow-up including functional outcomes. Results: A total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%). Conclusion: A substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters

Accelerometer derived load according to playing position in competitive youth soccer

The integration of accelerometers and Global Positioning Systems (GPS) provides the opportunity to objectively measure a players work output Although these systems have been widely adopted at the elite level, a positional profile of the external demands of soccer is currently missing from the literature. This study aimed to investigate the acceleration, deceleration and triaxial player load during competitive youth football. Eight 11v11 games were monitored during the competitive phase of the 2012-2013 season, using Catapult Minimax 5Hz GPS and 100Hz accelerometers. Analysis showed that wide midfielders completed significantly more maximal acceleration and deceleration actions. There were no reductions between playing halves in maximal acceleration or deceleration actions, across all playing positions. Central midfielders had a significantly higher total load, and a higher Y axis load compared to central defenders

The influence of footwear kinetic, kinematic and electromyographical parameters on the energy requirements of steady state running

The first aim of this study was to determine whether footwear with different shock attenuating properties can influence running economy. The second was to determine whether kinetic, 3-D kinematic and EMG parameters could be related to running economy. Twelve male participants completed 6-min of steady state treadmill running at 4.0 m.s-1 in two different footwear conditions with different mechanical shock attenuating properties. Kinetic, 3-D kinematic and EMG measures were synchronously obtained. The results show that whilst footwear with different shock attenuating properties do not affect running economy, key parameters of peak hip flexion, vastus medialis activation, peak plantar flexion velocity and sagittal plane knee excursion were found to be significant predictors of running economy. Future work should focus on implementing interventions to improve running economy

Differences in tibiocalcaneal kinematics measured with skin- and shoe-mounted markers

Purpose. The aim of the current investigation was to compare the 3-D tibiocalcaneal kinematics between skin- and shoe-mounted markers. Methods. Eleven male participants ran at 4.0m/s ± 5% along a 22 m runway. Tibiocalcaneal kinematics were captured simultaneously using markers placed externally on the shoe and on the skin through windows cut in the shoe. Paired t-tests were used to compare the 3-D kinematic parameters, and intraclass correlations were employed to contrast the kinematic waveforms. Results. Strong correlations were observed between the waveforms at R2 0.85. However, foot movements such as eversion range of motion, peak eversion, peak transverse plane range of motion, velocity of external rotation and peak eversion velocity were all significantly underestimated using shoe-mounted markers. Conclusions. The results indicate that shoe-mounted markers do not fully represent true foot movement