Anterior tibial compartment pressure during race walking

Design feature combinations effects of running shoe on plantar pressure during heel landing: A finite element analysis with Taguchi optimization approach

Large and repeated impacts on the heel during running are among the primary reasons behind runners’ injuries. Reducing plantar pressure can be conducive to reducing running injury and improving running performance and is primarily achieved by modifying the design parameters of running shoes. This study examines the effect of design parameters of running shoes (i.e., heel-cup, insole material, midsole material, and insole thickness) on landing peak plantar pressure and determines the combination of different parameters that optimize cushion effects by employing the Taguchi method. We developed the foot–shoe finite element (FE) model through reverse engineering. Model assembly with different design parameters was generated in accordance with the Taguchi method orthogonal table. The effectiveness of the model was verified using the static standing model in Ansys. The significance and contribution of different design parameters, and the optimal design to reduce plantar pressure during landing, were determined using the Taguchi method. In the descending order of percentage contribution was a conforming heel-cup (53.18%), insole material (25.89%), midsole material (7.81%), and insole thickness (2.69%). The more conforming heel-cup (p < 0.001) and softer insole (p = 0.001) reduced the heel pressure during landing impact. The optimal design of running shoe in this study was achieved with a latex insole, a 6 mm insole thickness, an Asker C-45 hardness midsole, and a 100% conforming heel-cup. The conforming heel-cup and the insole material significantly affected the peak plantar pressure during heel landing. The implementation of a custom conforming heel-cup is imperative for relieving high plantar pressure for long-distance heel-strike runners.

Long-Term Outcome of Mini-Open Surgical Decompression for Chronic Exertional Compartment Syndrome of the Forearm in Professional Motorcycling Riders

OBJECTIVE

To evaluate results of mini-open fasciotomy (MOF) in high-level motorcycling or motocross riders with chronic exertional compartment syndrome (CECS) at long-term follow-up (minimum 5 years).

DESIGN

Case series.

LEVEL OF EVIDENCE

IV.

SETTING

University Hospital/Private Practice.

PATIENTS

Fifty-four professional motorcycling riders treated with MOF for a CECS of the forearm from January 2006 to June 2011. Inclusion criteria comprised: high-level motorcycling or motocross riders, clinical symptoms of CECS for at least 6 months, diagnosis confirmed using preoperative compartment hydrostatic pressure measurement and/or magnetic resonance imaging of the forearm, minimum follow-up of 5 years.

INTERVENTIONS

A MOF to obtain decompression of all compartments was performed in all patients.

MAIN OUTCOME MEASURES

Visual analog scale; a subjective scale to measure strength; QuickDash functional scores. Time to resume full riding capacities as short-term evaluation.

RESULTS

A total of 54 patients who underwent 77 MOF procedures overall (23 bilateral) were included. The mean age was 23.6 ± 5.2 years. Mean Visual Analog Scale decreased from a preoperative value of 68.2 to a 3-month postoperative value of 26 (P < 0.001). Mean QuickDash scale was 84 at preoperative registration, falling to 20, 3 months after surgery (P < 0.001) and down to 12 at 1-year follow-up (P = 0.017). The average time to return to full riding capacities was 3.5 ± 1 week.

CONCLUSIONS

Mini-open fasciotomy resulted safe and effective for the treatment of chronic exertional compartment syndrome in high-level motorcycling or motocross riders. The good outcome at follow-up resulted stable at 5 years and the incidence of complications remained low. Our data demonstrate that the resolution of symptoms is reliable and durable. Pain recovery was immediate after surgery, instead functional scores showed a more gradual recovery throughout the 12 months after surgery.

CLINICAL RELEVANCE

Mini-open fasciotomy is a reliable treatment for CECS of the forearm in professional motorcycling riders. This treatment should also be considered in young riders due to the absence of tardive relapse reported in this study.

Analysis of lower limb work-energy patterns in world-class race walkers

The aim of this study was to analyse lower limb work patterns in world-class race walkers. Seventeen male and female athletes race walked at competitive pace. Ground reaction forces (1000 Hz) and high-speed videos (100 Hz) were recorded and normalised joint moments, work and power, stride length, stride frequency and speed estimated. The hip flexors and extensors were the main generators of energy (24.5 J (±6.9) and 40.3 J (±8.3), respectively), with the ankle plantarflexors (16.3 J (±4.3)) contributing to the energy generated during late stance. The knee generated little energy but performed considerable negative work during swing (-49.1 J (±8.7)); the energy absorbed by the knee extensors was associated with smaller changes in velocity during stance (r = .783, P < .001), as was the energy generated by the hip flexors (r = -.689, P = .002). The knee flexors did most negative work (-38.6 J (±5.8)) and the frequent injuries to the hamstrings are probably due to this considerable negative work. Coaches should note the important contributions of the hip and ankle muscles to energy generation and the need to develop knee flexor strength in reducing the risk of injury.

Endoscopic decompression for chronic compartment syndrome of the forearm in motocross racers

PURPOSE

Sporting activities that involve repetitive stress to muscle compartments can elicit chronic exertional compartment syndrome. Its occurrence in the lower leg muscle compartments is most common, but other locations are less well known and the pathophysiology is not completely understood. In motocross racers, chronic exertional compartment syndrome can occur in the muscles of the lower arm. Currently, the only accepted treatment of correctly diagnosed chronic exertional compartment syndrome is surgical release of the fascia, which successfully relieves pain and allows patients to return to full activity. Open decompression is considered as the gold standard of treatment. This clinical paper describes our new endoscopic technique and investigates the functional outcome after surgery.

METHODS

We report on a series of 154 chronic exertional compartment syndromes afflicted motocross racers treated with an endoscopic release of the lower arm muscles. An MRI scan before and after strenuous exercise of the hand flexors (repetitive grip until exhaustion for 15 min) was performed to confirm the clinical diagnosis of chronic exertional compartment syndrome. Symptom severity before and after surgery was assessed using a visual analogue scale.

RESULTS

Preoperative symptom severity scores were 1.1 ± 0.3 before exercise and 7.4 ± 1.5 after exercise. Post-operatively, these were 1.0 ± 0.2 and 1.7 ± 0.9. The pre- versus post-operative symptom scores after exercise were significantly different (p < 0.0001). No perioperative complications occurred, and at 6 weeks, all of the racers resumed their sportive activities.

CONCLUSION

It can be concluded that endoscopic release of the superficial compartment of the forearms of motocross racers diagnosed with chronic exertional compartment syndrome is a valuable treatment option, with mild post-operative pain and fast recovery.

Cardiocirculatory and metabolic responses at different walking intensities

OBJECTIVES

Although walking is a common physical activity, scientifically based training guidelines using standardised tests have not been established. Therefore this explorative study investigated the cardiovascular and metabolic load resulting from different walking intensities derived from maximal velocity (Vmax) during an incremental treadmill walking test.

METHODS

Oxygen uptake, heart rate (HR), blood concentrations of lactate and catecholamines, and rating of perceived exertion were recorded in 16 recreational athletes (mean (SD) age 53 (9) years) during three 30 minute walking trials at 70%, 80%, and 90% of Vmax (V70, V80, and V90) attained during an incremental treadmill walking test.

RESULTS

Mean (SD) oxygen uptake was 18.2 (2.3), 22.3 (3.1), and 29.3 (5.0) ml/min/kg at V70, V80, and V90 respectively (p<0.001). V70 led to a mean HR of 110 (9) beats/min (66% HRmax), V80 to 124 (9) beats/min (75% HRmax), and V90 to 152 (13) beats/min (93% HRmax) (p<0.001). Mean (SD) lactate concentrations were 1.1 (0.2), 1.8 (0.6), and 3.9 (2.0) mmol/l at V70, V80, and V90 respectively (p<0.001). There were no significant differences between catecholamine concentrations at the different intensities. Rating of perceived exertion was 10 (2) at V70, 12 (2) at V80, and 15 (2) at V90. Twelve subjects reported muscular complaints during exercise at V90 but not at V70 and V80.

CONCLUSIONS

Intensity and heart rate prescriptions for walking training can be derived from an incremental treadmill walking test. The cardiovascular and metabolic reactions observed suggest that V80 is the most efficient workload for training in recreational athletes. Further studies are needed to confirm these findings.

Ultrasound catheter placement for deep posterior compartment pressure measurements in chronic compartment syndrome

Medial shin pain, often referred to as shin splints, is a common but difficult to diagnose entity in many athletes. Chronic deep posterior compartment syndrome as a cause of medial leg pain is still controversial. The problems of deep posterior compartment pressure measurement contribute to this controversy. These problems include safety of catheter insertion and the possibility that the patient has more than one deep posterior compartment. In this paper, we present a new technique for catheter placement in which continuous ultrasound guidance is used. This technique allows for the safe placement of the catheter into the deep posterior compartment and for documentation of catheter tip location.

Fasciotomy for chronic compartment syndrome

During 1977 and 1978, we operated on 34 patients with chronic anterior tibial compartment syndrome. Surgery consisted of subcutaneous fasciotomy of the anterior crural compartment under local anesthesia. Twenty-three patients were operated on bilaterally. The mean follow-up was 10 years. One patient was lost to follow-up, leaving a total of 56 legs for assessment. The long-term result was excellent in 31 legs, good in 10, fair in 11, and poor in 4. There was one recurrence. This was relieved by refasciotomy.

The effect of locomotion speed on the anterior tibial intramuscular pressure of normal humans

We examined the hypothesis that anterior tibial intramuscular pressure increases with the speed of locomotion. A solidstate pressure transducer was placed near the tip of an intramuscular fluid-filled catheter and each of ten normal subjects walked, jogged and ran barefoot, at 1.5, 2.5 and 3.5 m s-1 respectively, on a treadmill to which they had been previously familiarized. The pressure signals during ten gait cycles from each subject were sampled at 600 Hz and were averaged at each speed. The peak pressures increased in magnitude as a function of increasing locomotion speed, while the mean pressure remained constant.