Running Style Research Articles

Metabolic responses and mechanisms during water immersion running and exercise.

The low impact nature of exercise in the water has increased interest in this form of exercise and specifically in water running as a cross-training modality. It is used as a possible preventative and therapeutic modality for rehabilitation. The high impact nature of land running predisposes the runner to stress of the lower limbs and overuse injuries. The need to reduce impact, as well as provide a low impact or non-weight-bearing condition for rehabilitation, has led runners and their coaches to the water. This increased interest by coaches and their athletes, attending sports medicine physicians and rehabilitative professionals has stimulated research into water immersion to the neck (WI) running. Exercise in the water has long been used by rehabilitative professionals with patients who have physically debilitating conditions (i.e. arthritis, musculoskeletal disorders) as it provides a medium for even those with limited mobility to exercise and relax their muscles. Numerous comparative studies into WI running from a metabolic as well as a training perspective have been published. WI has also long been used to simulate weightlessness for the comparative study of cardiorespiratory function and thermoregulation. WI and the associated cephalad shift in blood volume has implications on exercise responses during WI running exercise. In addition, the non-weight-bearing nature of WI running also raises issues of the cross-training benefits of WI running. WI running style and prior familiarity with the activity have been found to have a direct relationship with the comparability of WI to land running. This review presents current research into WI running, training specificity and comparative physiology.

Influence of shoes and heel strike on the loading of the hip joint

The forces and moments acting at the hip joint influence the long-term stability of the fixation of endoprostheses and the course of coxarthrosis. These loads may depend on the kind of footwear and the walking or running style. These factors were investigated in a patient with instrumented hip implants. He wore different sports shoes, normal leather shoes, hiking boots and clogs and walked barefoot with soft, normal and hard heel strikes. The loads were lowest while walking and jogging without shoes. All shoes increased the joint force and the bending moment at the implant slightly, but the torsional moment rose by up to 50%. No relation was found between the different type of shoes and the load increase, only shoes with very hard soles were clearly disadvantageous. Soft heels, soles or insoles did not offer advantages. Gait stability seems to play the most important role in increasing the joint loading and should be the criterion for the choice of footwear. Smooth gait patterns with soft heel strikes are the only means to reduce joint loading during slow jogging.

Distractibility and locomotor activity in rat following intra-collicular injection of a serotonin 1B-1D agonist

The superior colliculus (SC) is thought to be the decision center for reactions to novel and/or moving stimuli in the peripheral visual field. Serotonin 1B (5-HT 1B) receptors were previously demonstrated to be located on collicular axon terminals of retinal ganglion cells and their activation might depress afferent inputs from the retina. The effects of intra-collicular injections of 5-HT 1 drugs on distractibility were studied in hooded rats trained to run toward illuminated targets for a food reward in a 2-choice runway. 8-hydroxy-2-(di- n-propylamino)tetraline (8-OH-DPAT), a 5-HT 1A receptor agonist, RU 24969, a mixed 5-HT 1A and 5-HT 1B agonist, serotonin- O-carboxymethylglycyltyrosinamide (S-CM-GTNH 2), a mixed 5-HT 1B and 5-HT 1D receptor agonist and saline (control) were alternately injected. Following the S-CM-GTNH 2 treatment alone, animals exhibited an erratic running style, involving side-to-side movements of the head, without change in the overall accuracy of their locomotor trajectories, but with substantial decrease in their running speed. When distracting peripheral lights were introduced at the mid-points of the animals' run, in the weaker distracting condition (unilateral distractor) only, distraction indexes were found lower following the S-CM-GTNH 2 treatment than following the other drug or saline treatments. It is concluded that serotonin, via 5-HT 1B-1D receptors, may induce an elevation of the visual distractibility threshold by modulating directly the transmission of the primary visual signal.

A kinematic comparison of overground and treadmill running

Treadmills are often used in research projects to simulate overground locomotion, assuming that locomotion is similar on a treadmill and overground. The purpose of this investigation was to determine whether a treadmill could be used to simulate overground locomotion. Twenty-two subjects ran on four different surfaces: overground and three treadmills that differed in size and power. The kinematics of the right leg and foot were studied using two high-speed Locam cameras (lateral and posterior view). The subjects ran in two different shoes at four different speeds (3.0-6.0 m.s-1). The differences in the kinematics between treadmill and overground running could be divided into systematic and subject dependent components. Subjects systematically planted their feet in a flatter position on the treadmill than overground. Most of the lower extremity kinematic variables, however, showed inconsistent trends for individual subjects, depending on the individual subject's running style, running speed, and shoe/treadmill situation. The differences were substantial. It is not yet understood how the human locomotor system adapts to a particular treadmill running situation. However, it is concluded that individual assessment of running kinematics on a treadmill for shoe or shoe orthotic assessment may possibly lead to inadequate conclusions about overground running.

Shin Splints and Forefoot Contact Running: A Case Report

Many athletes develop shin splints after athletic activity. The purpose of this case report is to describe the treatment of a patient with posteromedial tibial pain (shin splints) who habitually ran with a forefoot contact running style. The 20-year-old male patient, who played volleyball and basketball about 7 hours a week, complained of pain in the middle one-third of the posteromedial tibia after an acute but prolonged episode of running. Routine observational analysis and in-shoe pressure analysis of the patient's running style showed that he habitually ran on his toes with an absence of heelstrike (forefoot contact running). After instructing the patient on heel-toe running, he no longer complained of posteromedial tibial bone pain. Several possible reasons are proposed for the reduction of leg pain following cessation of forefoot contact running. This case report proposes forefoot contact running as a possible contributor to posteromedial shin splints and that a change in running style may be the optimal treatment for some patients.

Is running style and economy affected by wearing respiratory apparatus?

The purposes of this investigation were to compare selected gait parameters characteristic of running without respiratory apparatus on a treadmill (NOR) with those displayed while wearing a mouthpiece-breathing valve apparatus (MP) and while wearing a respiratory face mask (MASK), and to compare the running economy (RE) measured during MP with that measured during MASK. Seventeen male volunteers [age = 32 +/- 5 yr (mean +/- SD); mass = 72.4 +/- 9.0 kg] performed three treadmill runs in randomly assigned order. All runs were identical in terms of duration (10 min), speed [200 m. min-2 (7.5 mph)], and grade (0%). During the last minute of each run, RE was measured and coordinate data were collected for determination of mechanical variables. The mechanical analyses were limited to 12 subjects. Stride length, vertical oscillation of the center of mass, hip and ankle range of motion, and average internal mechanical power output were not different for NOR, MP, and MASK. Knee range of motion was significantly less (P < or = 0.05) during MP than during NOR and MASK, primarily due to a significant reduction in maximum knee flexion during nonsupport. MASK RE was not significantly different (P > 0.05) from MP RE. It was concluded that wearing MP or MASK generally does not affect running style of individuals running at comfortable, submaximal running speeds and that RE measured with MP is not different from that measured with MASK.

Changes in Distance Running Mechanics Due to Systematic Variations in Running Style

There is little information on how a change in one feature of an individual’s running mechanics affects other aspects of running style. This study manipulated experimental conditions such that eight subjects ran with three different step lengths, three step widths, and three varying degrees of shoulder rotation. The effect of these changes on rearfoot pronation measures, step length, and step width were examined. Results showed that varying step length over a range of 18 cm and shoulder rotation over a range of 17° caused no significant differences in maximal pronation angle, total amount of pronation, or maximal pronation velocity. Varying step width from landing approximately 5 cm lateral to the midline to crossing over a midline by 2 cm increased the maximum pronation from 12.2 to 18.3°, the amount of pronation from 14.1 to 21.1°, and maximal pronation velocity from. 329°/s to 535°/s. It is suggested that runners with problems due to excessive pronation might try changing step width. Changes in step width and shoulder rotation had no significant effect on step length, and alterations to shoulder rotation did not affect step length or step width significantly. These results suggest that a runner attempts to maintain some aspects of running mechanics despite major alterations to other elements of running style.

Association-dissociation patterns of United States Olympic Marathon Trial contestants

The association-dissociation cognitive patterns of United States Olympic Marathon Trial contestants were investigated on the basis of responses to the Running Styles Questionnaire. The night prior to the Olympic Trials, 32 subjects responded to 12 multiple-choice-type questions and 6 open-ended questions that probed the type of cognitions processed by the athletes at different stages of the race. Discriminant function analysis resulted in a significant multivariate solution (p <.01), with 5 of the 12 multiple-choice questions maximizing the separation of athletes into groups of top- and lower-place finishers. The composite of these 5 questions suggested that top finishers employed cognitive strategies that utilized both associative and dissociative techniques. Lower finishers demonstrated a composite that indicated the early adoption and maintenance of a dissociative strategy. On the basis of the multivariate solution, athletes were classified to appropriate group membership with 71.88% overall accuracy. The results tend to support the contention that cognitive strategies employed during marathon racing are related to the participant's performance level.

Evaluation of Rearfoot Asymmetries in Running with Worn and New Running Shoes

The purpose of this study was to identify the kinematic characteristics of bilateral rearfoot asymmetry during heel–toe running under two experimental conditions: worn (broken-in) running shoes and new (standardized) running shoes. High-speed cinematography (150 fps) was used to film the lower limbs of four male runners in the frontal plane while running on a treadmill at their training pace. Six successive footfalls were analyzed for each subject and selected kinematical variables of the rearfoot function were calculated. Significant asymmetries were found in lower leg angle and Achilles tendon angle at touchdown and at maximum pronation. Total pronation and rearfoot angle were almost symmetric. The angular displacement graphs for the shank and foot revealed a distinct overall asymmetry between the lower limbs in both conditions. The mean values of the kinematical asymmetries were appreciably higher in the new shoe condition. It is proposed that the degree of these asymmetries is subject to changes due to injury, personal running style, and stability of the running shoe. Trends of bilateral dominance specific to rearfoot control in running were identified.

Influence of Attached Masses on Impact Forces and Running Style in Heel-Toe Running

Impact forces analysis in heel-toe running is often used to examine the reduction of impact forces for different running shoes and/or running techniques. Body mass is reported to be a dominant predictor of vertical impact force peaks. However, it is not evident whether this finding is only true for the real body mass or whether it is also true for additional masses attached to the body (e.g., running with additional weight or heavy shoes). The purpose of this study was to determine the effect of additional mass on vertical impact force peaks and running style. Nineteen subjects (9 males, 10 females) with a mean mass of 74.2 kg/56.2 kg (SD = 10.0 kg and 6.0 kg) volunteered to participate in this study. Additional masses were attached to the shoe (.05 and .1 kg), the tibia (.2, .4, .6 kg), and the hip (5.9 and 10.7 kg). Force plate measurements and high-speed film data were analyzed. In this study the vertical impact force peaks, Fzi, were not affected by additional masses, the vertical active force peaks, Fza, were only affected by additional masses greater than 6 kg, and the movement was only different in the knee angle at touchdown, ϵ0, for additional masses greater than .6 kg. The results of this study did not support findings reported earlier in the literature that body mass is a dominant predictor of external vertical impact force peaks.

Hamstring injuries. Proposed aetiological factors, prevention, and treatment.

Injuries to the hamstring muscles can be devastating to the athlete because these injuries frequently heal slowly and have a tendency to recur. It is thought that many of the recurrent injuries to the hamstring musculotendinous unit are the result of inadequate rehabilitation following the initial injury. The severity of hamstring injuries is usually of first or second degree, but occasionally third-degree injuries (complete rupture of the musculotendinous unit) do occur. Most hamstring strain injuries occur while running or sprinting. Several aetiological factors have been proposed as being related to injury of the hamstring musculotendinous unit. They include: poor flexibility, inadequate muscle strength and/or endurance, dyssynergic muscle contraction during running, insufficient warm-up and stretching prior to exercise, awkward running style, and a return to activity before complete rehabilitation following injury. Treatment for hamstring injuries includes rest and immobilisation immediately following injury and then a gradually increasing programme of mobilisation, strengthening, and activity. Permission to return to athletic competition should be withheld until full rehabilitation has been achieved (complete return of muscle strength, endurance, and flexibility in addition to a return of co-ordination and athletic agility). Failure to achieve full rehabilitation will only predispose the athlete to recurrent injury. The best treatment for hamstring injuries is prevention, which should include training to maintain and/or improve strength, flexibility, endurance, co-ordination, and agility.

An analysis of overground and treadmill sprinting

Selected variables were measured to examine differences in overground and treadmill running at sprinting speeds of maximal effort. Five college-varsity sprinters volunteered to run 100-yd sprints in both overground and treadmill running conditions. After a minimum of 10 training sessions on the treadmill, the subjects were filmed (75 fps) sprinting 100 yd and expired respiratory gases were collected during an 18-min recovery period. The oxygen debt of the overground condition, means = 47.86 ml X kg-1, was 36% greater than the treadmill running condition, means = 30.64 ml X kg-1. Regardless of individual running style, the major biomechanical differences between treadmill and overground running conditions occurred during the support phase and were observed in the supporting leg. During treadmill running, the leg of the supporting lower extremity was less erect at contact (means = 83.9 vs 88.3 deg) and moved through a greater range of motion (means = 60.6 vs 54.5 deg) with a faster overall angular velocity (means = 566.36 vs 478.07 deg X s-1). The thigh of the supporting lower extremity was more erect at contact (means = 67.1 vs 61.1 deg) and moved with a slower overall angular velocity (means = 435.14 vs 528.77 deg X s-1). Data suggest that the moving treadmill belt reduces the energy requirements of the runner by bringing the supporting leg back under the body during the support phase of running.