Impacts and kinematic adjustments during an exhaustive run

Abstract

The increase in peak impact accelerations at the leg was not considered an increased injury risk because of the decreased effective mass. The altered kinematics may have resulted in increased metabolic costs during the latter stages of the exhaustive run.

Reducing Impact Loading During Running With the Use of Real-Time Visual Feedback

“…It is unlikely that fatigue caused the reductions, because fatigue from running on a treadmill at a continuous speed has been found to increase PPA rather than decrease it. 12,42 With regard to the data collection at the end of the nofeedback period, in motor-skill-learning studies the retention test is usually given after a rest period. This is typically hours or days after the training.…”

Difference in Mechanical and Energy Cost between Highly, Well, and Nontrained Runners

“…Highly trained runners cover very long distances during training session, and perform a very high number of strides (more than 20 km.day -1 ; (6)) compared to the other populations studied. For example, running 32 km.week -1 will produce over 1.3 million impacts to the body over a period of one year (16). More frequent impacts will place greater stress on the muscles, tendons and bones resulting in an increased risk of injury and degenerative disease (15).…”

Muscle Coactivation Before and After the Impact Phase of Running Following Isokinetic Fatigue

“…1,2 In theory, the impulsive forces exerted when the foot contacts the ground may also contribute to musculoskeletal injuries. 3 Compared with other movements, the ground reaction forces are relatively small, 4 with magnitudes up to 2.32 3 body weight (BW) and an impact load rate of 113 3 BW/s. 5 It has been suggested 1,[6][7][8][9] that when these impact loads are exerted continuously during repetitive running cycles, then injury risk might increase.…”

“…10,17,18 These joint kinematic changes result in a decrease in the portion of the body mass that is accelerated when the foot contacts the ground (ie, effective mass). 3 The lower the effective mass, the greater the leg impact and attenuation. 3 The kinematic changes in the fatigued runner are the result of muscle-performance impairments that contribute to the runner's inability to maintain the same technique for a long period of time.…”

“…3 The lower the effective mass, the greater the leg impact and attenuation. 3 The kinematic changes in the fatigued runner are the result of muscle-performance impairments that contribute to the runner's inability to maintain the same technique for a long period of time. Such changes may increase injury potential, especially in less-experienced runners and runners with muscle weaknesses or imbalances.…”