Neuromuscular fatigue and recovery dynamics following prolonged continuous run at anaerobic threshold

Objective

The aim of this study was to determine the influence of intensive aerobic running on some muscle contractile characteristics and the dynamics of their recovery during a 2 hour period afterwards.

Methods

Seven well trained runners performed a 6 km run at anaerobic threshold (V_OBLA). Knee torque during single twitch, low and high frequency electrical stimulation (ES), maximum voluntary knee extension, and muscle activation level test of the quadriceps femoris muscles were measured before and immediately after the run, and at several time points during a 120 minute interval that followed the run.

Results

After exercise, the mean (SE) maximum twitch torque (T_TW) and torque at ES with 20 Hz (low frequency ES; T_F20) dropped by 14.1 (5.1)% (p<0.05) and 20.6 (7.9)% (p<0.05) respectively, while torque at stimulation with 100 Hz (high frequency ES; T_F100), maximum isometric knee extension torque (maximum voluntary contraction torque; T_MVC), and activation level did not change significantly. Twitch contraction time was shortened by 8 (2)% (p<0.05). Ten minutes after the run, T_TW was 40% higher than immediately after the run and 10% (p<0.05) higher than before the run. T_F20, T_F100, and T_MVC remained lower for 60 minutes (p<0.05) than before the run.

Conclusions

A 6 km continuous run at V_OBLA caused peripheral fatigue by impairing excitation–contraction coupling. Twitch torque recovered very quickly. However, the process of torque restoration at maximum isometric knee extension torque and at high and low frequency ES took much longer.     

Live high-train low associated with increased haemoglobin mass as preparation for the 2003 World Championships in two native European world class runners

Background

It is unclear whether world class endurance athletes, in contrast with less well trained subjects, increase their haemoglobin mass on a regimen of living high and training low (LHTL).

Objective

To assess whether haemoglobin mass increases in world class athletes on LHTL and whether this increase is associated with peak performance at a subsequent important competition.

Methods

Two Swiss world class runners (one 5000 m and one marathon) lived for 26 days (18 hours a day) at an altitude of 2456 m and trained at 1800 m. This LHTL camp was the preparation for the World Athletic Championships taking place 27–29 days after the end of the camp. Haemoglobin mass and other haematological variables were measured before and after the LHTL camp. The performance parameter was the race times during that period.

Results

Haemoglobin mass increased by 3.9% and 7.6%, and erythrocyte volume by 5.8% and 6.3%. The race times, as well as the ranking at the World Championships, indicated clearly improved performance after the LHTL camp.

Conclusions

The results suggest that LHTL with an adequate dose of hypoxia can increase haemoglobin mass even in world class athletes, which may translate into improved performance at important competitions at sea level.     

Effect of aging on the stride pattern of veteran marathon runners

Objective

To investigate the stride pattern of different age groups of veteran runners in a marathon road race.

Methods

This kinematic study investigated the stride pattern (stride length, stride period, velocity, stance time, and non‐stance time) for 151 runners (78 men aged up to 75–80, 73 women aged up to 60–64) at the 7 mile point.

Results

Significant declines for men with aging were found for mean stride length (from 2.4 m at age 40–49 to 2.0 m at age 60+), velocity, and non‐stance time (p<0.05), whereas stride period changed little. The findings indicate that the lower velocities of older runners are associated with shorter strides whereas cadence changes little. However, when a statistical adjustment was made for the variation in runners'' velocity, it was found that older runners did not have a significantly shorter stride length at any given velocity.

Conclusion

Although a shorter stride is the mechanical route by which older runners lose velocity, the shorter stride may not be the fundamental cause of the velocity reduction with age. This has implications for researchers and coaches when investigating and training veteran distance runners.     

Eccentric treatment for patellar tendinopathy: a prospective randomised short-term pilot study of two rehabilitation protocols

Objective

To compare the efficacy and safety of two eccentric rehabilitation protocols for patients with symptomatic patellar tendinopathy. A new eccentric overload training device was compared with the present standard eccentric rehabilitation programme on a decline board.

Design

Prospective, randomised clinical trial.

Setting

Sports rehabilitation clinic, university sports laboratory, supplemented with home exercises.

Patients

20 competitive and recreational athletes, all with clinical diagnosis of patellar tendinopathy, verified by MRI or ultrasound imaging.

Interventions

A 12‐week rehabilitation period, either with bilateral eccentric overload strength training using the Bromsman device twice a week or with unilateral eccentric body load training using a decline board twice a week, supplemented with daily home exercises.

Outcome measures

The primary outcome was pain and function, assessed by the Swedish Victorian Institute of Sport Assessment for Patella (VISA‐P) score. Secondary outcome measures were isokinetic muscle torque, dynamic function and muscle flexibility, as well as pain level estimations using visual analogue scale (VAS). Side effects were registered.

Results

Both treatment groups improved in the short term according to the VISA‐P scores during the 12‐week rehabilitation period. However, there were no significant differences between the groups in terms of pain and function. After a 3‐month rehabilitation period, most patients could be regarded as improved enough to be able to return to training and sports. No serious side effects were detected in either group.

Conclusion

In patients with patellar tendinopathy pain, two‐legged eccentric overload training twice per week, using the new device (Bromsman), was as efficient and safe as the present standard daily eccentric one‐legged rehabilitation‐training regimen using a decline board.Proximal patellar tendon pain (patellar tendinopathy) occurs typically in sports characterised by high demands on force and power of the leg extensor muscles, such as basketball, volleyball, tennis and soccer. Controlled eccentric strengthening of the muscle–tendon complexes involved seems to be important for successful rehabilitation.^1,2,3,4,5 Eccentric squat training on a decline board has been shown to have a superior therapeutic effect in reduction of pain compared with squatting on a flat surface.⁶ One‐legged squatting, using the decline board, resulted in encouraging results with, for example, earlier return to a functional level of sport.^7,8 By contrast, Visnes et al⁹ showed no significant improvements of eccentric training on patellar tendinopathy among volleyball players when instituted during the playing season.Previous research suggests that the efficacy of eccentric squatting rehabilitation may be correlated with the load applied to the quadriceps muscle. The aim of the present prospective randomised short‐term study was to evaluate and compare clinical outcomes in terms of knee pain and function after eccentric training, using either a novel eccentric overload training device (Bromsman, Lidingö, Sweden)¹⁰ or the current standard programme of one‐leg squatting exercises.¹¹     

Exercise associated hyponatraemia: quantitative analysis to understand the aetiology

Background

The development of symptomatic hyponatraemia consequent on participation in marathon and ultraendurance races has led to questions about its aetiology and prevention.

Objectives

To evaluate: (a) the assertion that sweat sodium losses cannot contribute to the development of hyponatraemia during endurance exercise; (b) the adequacy of fluid replacement recommendations issued by the International Marathon Medical Directors Association (IMMDA) for races of 42 km or longer; (c) the effectiveness of commercial sports drinks, compared with water, for attenuating plasma sodium reductions.

Methods

A mathematical model was used to predict the effects of different drinking behaviours on hydration status and plasma sodium concentration when body mass, body composition, running speed, weather conditions, and sweat sodium concentration were systematically varied.

Results

Fluid intake at rates that exceed sweating rate is predicted to be the primary cause of hyponatraemia. However, the model predicts that runners secreting relatively salty sweat can finish ultraendurance exercise both dehydrated and hyponatraemic. Electrolyte‐containing beverages are predicted to delay the development of hyponatraemia. The predictions suggest that the IMMDA fluid intake recommendations adequately sustain hydration over the 42 km distance if qualifiers—for example, running pace, body size—are followed.

Conclusions

Actions to prevent hyponatraemia should focus on minimising overdrinking relative to sweating rate and attenuating salt depletion in those who excrete salty sweat. This simulation demonstrates the complexity of defining fluid and electrolyte consumption rates during athletic competition.     

Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study

Background

Ultra‐endurance running is emerging as a popular sport in Western industrialised countries. Gastrointestinal bleeding has been reported to be an adverse effect in these runners.

Objective

To see if the oral administration of a proton pump inhibitor would reduce the incidence of gastrointestinal bleeding in an ultramarathon.

Methods

In a randomised, double blinded, placebo controlled study, a prophylactic regimen of three days of an oral proton pump inhibitor (pantoprazole 20 mg) was tested in healthy athletes participating in the Spartathlon ultramarathon. The incidence of gastrointestinal bleeding was assessed by a stool guaiac test.

Results

Results were obtained for 70 healthy volunteers. The data for 20 of 35 runners in the intervention group and 17 of 35 runners in the placebo group were entered into the final analysis. At the end of the ultramarathon, two subjects in the intervention group and 12 in the placebo group had positive stool guaiac tests (risk difference 0.86; 95% confidence interval 0.45 to 0.96; p  =  0.001).

Conclusion

A short prophylactic regimen of oral proton pump inhibition can successfully decrease the incidence of gastrointestinal bleeding in participants in an ultramarathon.     

Strength and endurance training reduces the loss of eccentric hamstring torque observed after soccer specific fatigue

ObjectivesTo investigate the effect of two hamstring training protocols on eccentric peak torque before and after soccer specific fatigue.ParticipantsTwenty-two university male soccer players.DesignIsokinetic strength tests were performed at 60°/s pre and post fatigue, before and after 2 different training interventions. A 45-min soccer specific fatigue modified BEAST protocol (M-BEAST) was used to induce fatigue. Players were randomly assigned to a 4 week hamstrings conditioning intervention with either a maximum strength (STR) or a muscle endurance (END) emphasis.Main outcome measuresThe following parameters were evaluated: Eccentric peak torque (EccPT), angle of peak torque (APT), and angle specific torques at knee joint angles of 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° and 90°.ResultsThere was a significant effect of the M-BEAST on the Eccentric torque angle profile before training as well as significant improvements in post-fatigue torque angle profile following the effects of both strength and muscle endurance interventions.ConclusionsForty-five minutes of simulated soccer activity leads to reduced eccentric hamstring torque at longer muscle lengths. Short-term conditioning programs (4-weeks) with either a maximum strength or a muscular endurance emphasis can equally reduce fatigue induced loss of strength over this time period.     

Spatiotemporal characteristics of habitually shod runners change when performing barefoot running

Introduction

Habitually shod rear-foot strike (RFS) runners demonstrate changes in spatiotemporal variables when running barefoot; however, it is unknown whether these changes are a function of running barefoot and/or adopting different foot-strike patterns. Therefore, the purpose of this study was to examine changes in spatiotemporal variables when habitually shod RFS runners transition to barefoot running.

Methods

Inverse dynamic methodology was used to examine 22 habitually shod RFS runners who performed overground running, shod and barefoot. Runners were grouped according to their novice barefoot foot-strike pattern: RFS, mid-foot strike (MFS) and forefoot strike (FFS). Runners were also grouped to examine differences between shod and barefoot running.

Results

Of the 22 RFS shod runners, 5 adopted a FFS, 9 adopted a MFS, and 8 maintained a RFS during novice barefoot running. We report a significant main effect of running barefoot for spatiotemporal variables, but not for foot-strike pattern. Relative to when shod, all groups of runners took shorter strides and steps. RFS and MFS runners also exhibited higher step frequency and exhibited shorter step and cycle times, while RFS and FFS runners both exhibited shorter stance times. These findings indicate that barefoot running has a significant influence on spatiotemporal measures, regardless of utilized foot-strike pattern.

     

Effect of static stretching of muscles surrounding the knee on knee joint position sense

Background

Muscle stretching is widely used in sport training and in rehabilitation. Considering the important contribution of joint position sense (JPS) to knee joint stability and function, it is legitimate to question if stretching might alter the knee JPS.

Objective

To evaluate if a stretch regimen consisting of three 30 s stretches alters the knee JPS.

Design and setting

A blinded, randomised design with a washout time of 24 h was used.

Subjects

39 healthy students (21 women, 18 men) volunteered to participate in this study.

Methods and main outcome measures

JPS was estimated by the ability to reproduce the two target positions (20° and 45° of flexion) in the dominant knee. The absolute angular error (AAE) was defined as the absolute difference between the target angle and the subject perceived angle of knee flexion. AAE values were measured before and immediately after the static stretch. Measurements were repeated three times. The static stretch comprised a 30 s stretch followed by a 30 s pause, three times for each muscle.

Results

The AAE decreased significantly after the stretching protocols for quadriceps (3.5 (1.3) vs 0.7 (2.4); p<0.001), hamstring (3.6 (2.2) vs 1.6 (3.1); p = 0.016) and adductors (3.7 (2.8) vs 1.7 (2.4); p = 0.016) in 45° of flexion, but no differences were found for values of the gastrocnemius and popliteus muscles in this angle and for the values of all muscles in 20° of flexion (p>0.05).

Conclusion

The accuracy of the knee JPS in 45° of flexion is improved subsequent to a static stretch regimen of quadriceps, hamstring and adductors in healthy subjects.     

Regional bone mineral density in male athletes: a comparison of soccer players, runners and controls

Objectives

To investigate the association of soccer playing and long‐distance running with total and regional bone mineral density (BMD).

Design

Cross‐sectional study.

Setting

Academic medical centre.

Participants

Elite male soccer players (n = 15), elite male long‐distance runners (n = 15) and sedentary male controls (n = 15) aged 20–30 years.

Main outcome measurements

BMD (g/cm²) of the lumbar spine (L1–L4), right hip, right leg and total body were assessed by dual‐energy x‐ray absorptiometry, and a scan of the right calcaneus was performed with a peripheral instantaneous x‐ray imaging bone densitometer.

Results

After adjustment for age, weight and percentage body fat, soccer players had significantly higher whole body, spine, right hip, right leg and calcaneal BMD than controls (p = 0.008, p = 0.041, p<0.001, p = 0.019, p<0.001, respectively) and significantly higher right hip and spine BMD than runners (p = 0.012 and p = 0.009, respectively). Runners had higher calcaneal BMD than controls (p = 0.002). Forty percent of the runners had T‐scores of the lumbar spine between −1 and −2.5. Controls were similar: 34% had T‐scores below −1 (including 7% with T‐scores lower than −2.5).

Conclusions

Playing soccer is associated with higher BMD of the skeleton at all sites measured. Running is associated with higher BMD at directly loaded sites (the calcaneus) but not at relatively unloaded sites (the spine). Specific loading conditions, seen in ball sports or in running, play a pivotal role in skeletal adaptation. The importance of including an appropriate control group in clinical studies is underlined.     

Effects of brief yoga exercises and motivational preparatory interventions in distance runners: results of a controlled trial

Objective

To examine the efficacy of two preparatory interventions on one mile run performance in 90 high school long distance runners.

Method

After participants had completed a one mile baseline run, they were randomly assigned to participate in either one of two interventions (brief yoga exercises, motivational shouting exercises) or a no intervention control condition. Experimental conditions were implemented one week after the baseline run about 20 minutes before a second one mile trial.

Results

Participants assigned to the motivational intervention improved their running performance significantly more than those assigned to the other two conditions. Although the magnitude of the effect was small, participants assigned to yoga exercises showed significant improvements in running performance relative to control condition participants. Consumer satisfaction ratings indicated that participants who were assigned to the motivational and yoga exercise groups liked their interventions more than those assigned to the control group.

Conclusion

Motivational and yoga interventions designed to improve long distance running performance were equally acceptable to the participants, but the former had a greater effect.     

Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level

Objectives

To investigate possible links between aetiology of acute, first time hamstring strains in sprinters and dancers and recovery of flexibility, strength, and function as well as time to return to pre‐injury level.

Methods

Eighteen elite sprinters and 15 professional dancers with a clinically diagnosed hamstring strain were included. They were clinically examined and tested two, 10, 21, and 42 days after the acute injury. Range of motion in hip flexion and isometric strength in knee flexion were measured. Self estimated and actual time to return to pre‐injury level were recorded. Hamstring reinjuries were recorded during a two year follow up period.

Results

All the sprinters sustained their injuries during high speed sprinting, whereas all the dancers were injured while performing slow stretching type exercises. The initial loss of flexibility and strength was greater in sprinters than in dancers (p<0.05). At 42 days after injury, both groups could perform more than 90% of the test values of the uninjured leg. However, the actual times to return to pre‐injury level of performance were significantly longer (median 16 weeks (range 6–50) for the sprinters and 50 weeks (range 30–76) for the dancers). Three reinjuries were noted, all in sprinters.

Conclusion

There appears to be a link between the aetiologies of the two types of acute hamstring strain in sprinters and dancers and the time to return to pre‐injury level. Initially, sprinters have more severe functional deficits but recover more quickly.     

Calcitonin gene related peptide and neuropeptide Y in skeletal muscle after eccentric exercise: a microdialysis study

Objectives

To detect neuropeptides in human skeletal muscle at rest and after eccentric exercise.

Method

Eight healthy subjects participated in the study. Microdialysis of the distal part of the vastus lateralis of the quadriceps muscle and pain evaluation were performed immediately after eccentric exercise, after two days, and at rest. Calcitonin gene related peptide (CGRP) and neuropeptide Y (NPY), representatives of the sensory and autonomic nervous system, were analysed by radioimmunoassay.

Results

Overall, the measured concentrations were low, some even below the limit of detection. At rest, CGRP was detected in two of seven samples, but after eccentric exercise it was detected in 27 of 30 samples. At rest, all NPY concentrations were below the limit of detection, but after exercise it was found in six of 30 samples.

Conclusion

The significant increase in detectability of CGRP after eccentric exercise may be related to the increased experience of pain. Therefore the occurrence of CGRP after heavy eccentric exercise may be associated with the regulation of delayed onset muscle soreness and possibly also the stimulation of tissue regeneration.     

Do ground reaction forces during unilateral and bilateral movements exhibit compensation strategies following ACL reconstruction?

Purpose

The aims of the study were (1) to evaluate the leg asymmetry assessed with ground reaction forces (GRFs) during unilateral and bilateral movements of different knee loads in anterior cruciate ligament (ACL) reconstructed patients and (2) to investigate differences in leg asymmetry depending on the International Knee Documentation Committee Subjective Form (IKDC) in order to identify potential compensation strategies.

Methods

The knee function of 50 ACL reconstructed (patella tendon) patients was examined at 31 ± 7 months after the surgery. GRFs were quantified during the sit-to-stand and stand-to-sit test, the step-up and step-down test, and the two- and one-leg vertical jump. Further, the IKDC score, the anterior–posterior knee laxity, and the concentric torque of the quadriceps and hamstring muscles were evaluated.

Results

Differences between the operated and non-operated leg were found in the knee laxity, the quadriceps torque, and GRFs. The patients with low IKDC scores demonstrated greater leg asymmetries in GRFs compared to the patients with high IKDC scores.

Conclusions

ACL reconstructed patients showed GRF asymmetries during unilateral and bilateral movements of different knee loads. Three compensation strategies were found in patients with low subjective knee function: (1) a reduced eccentric load, (2) an inter-limb compensation during bilateral movements, and (3) the avoidance of high vertical impact forces. These compensation strategies may be indicative of a protective adaptation to avoid excessive ACL strain. GRF measurements are practicable and efficient tools to identify individual compensation strategies during early rehabilitation.

     

Surgical treatment of partial tears of the proximal origin of the hamstring muscles

Background

Hamstring injuries are common especially in athletes. Partial and complete tears of the proximal origin may cause pain and functional loss.

Objective

To evaluate the results of surgical treatment for partial proximal hamstring tears.

Methods

Between 1994 and 2005, 47 athletes (48 cases, 1 bilateral) with partial proximal hamstring tears were operated on. The cases were retrospectively analysed. Before surgery, 42 of the patients had undergone conservative treatment with unsatisfactory results, whereas in five patients the operation was performed within four weeks of the injury.

Results

The mean length of the follow up was 36 months (range 6–72). The result of the operation was rated excellent in 33 cases, good in nine, fair in four, and poor in two. Forty one patients were able to return to their former level of sport after an average of five months (range 1–12).

Conclusion

In most cases, excellent or good results can be expected after surgical repair of partial proximal hamstring tears even after conservative treatment has failed.     

Factors associated with menstrual dysfunction and self-reported bone stress injuries in female runners in the ultra- and half-marathons of the Two Oceans

Objective

To investigate factors associated with menstrual dysfunction, self‐reported bone stress injuries and energy balance in women runners.

Methods

613 runners were randomly sampled during the registration period for an endurance event. Demographic information, including self‐reported height and weight, training and injury history and menstrual history, was collected by questionnaire.

Results

Ultra‐marathon (ULTRA) participants (n = 276) were significantly older (mean (SD) 39 (8.2) vs 34 (10.5) years; p<0.001), lighter (58.2 (6.6) vs 59.6 (8.3) kg; p<0.05) and reported a higher training volume (p<0.001) than half‐marathon (HALF) participants (n = 337). Significantly more ULTRA subjects than HALF subjects reported a previous bone stress injury (21% vs 14%; p<0.05). There was no difference between the groups for menstrual status, but age at menarche was later (p<0.01) in the ULTRA group. Data were combined according to the absence (REG; n = 368/602 (61%)) or presence (IRREG; n = 234/602 (39%)) of a history of menstrual irregularity. Subject morphology was similar between groups, but the IRREG group had a higher self‐reported measure on the self‐loathing subscale (SLSS; p<0.01). The whole group was then classified according to current menstrual status, with 165 women being classified as currently irregular. (OLIGO/AMEN; 11.6%) and 445 women as currently regular (EUMEN; 88.4%). There were no morphological differences between the groups, however the OLIGO/AMEN group had a later age of menarche (p<0.01) than the EUMEN group. Further, women who reported a previous bone stress injury had higher SLSS scores than those who did not (2.91 (0.98) vs 2.68 (0.84); p<0.05).

Conclusions

There may be two independent mechanisms associated with energy balance, which are related to bone stress injuries, but may not necessarily be related to menstrual dysfunction.     

The effects of marathon running on three-dimensional knee kinematics during walking and running in recreational runners

BackgroundRunning-related musculoskeletal injuries are common. Knee injuries are most frequent, and often occur during or shortly after marathons.Research questionThe effects of a marathon on runners’ knee kinematics remain unclear. No studies have shown comprehensive three-dimensional (3D) knee kinematic changes following a marathon. This study aimed to observe the effects of running a marathon on 3D knee kinematics and identify the phases of walking and running gait in which significant changes occur.MethodsBased on an electronic survey, 10 healthy, recreational runners (20 knees) with similar running experience were included. Their 3D knee kinematics (during treadmill walking and running) were collected using a portable, optical motion capture system within 24 h before and within 6 h after running a marathon.ResultsAll measurements after the marathon were compared with pre-marathon measurements. (1) For walking post-marathon: varus rotation increased by 1.8° [95% confidence interval (CI) 0.1–3.4, P = 0.036] at peak knee extension during stance; anterior translation increased by 2.2 mm (95% CI 0.3–4.1, P = 0.025) at initial contact; range of motion (ROM) in internal-external rotation increased less than 1°, P = 0.023; ROM in anteroposterior translation increased by 3.8 mm, P = 0.048. (2) For running post-marathon: flexion rotation increased by 1.6° (95% CI 0.2–2.9, P = 0.025) at initial contact; varus rotation increased by 2.0° (95% CI 0.2–3.8, P = 0.031) at peak knee extension during stance.SignificanceSignificant differences in varus rotation and anterior translation were identified following a marathon, which could potentially contribute to injury. These results provide important information for runners and coaches about knee kinematic alterations following a marathon.     

Effects of long term Tai Chi practice and jogging exercise on muscle strength and endurance in older people

Objectives

To investigate the influence of regular Tai Chi (TC) practice and jogging on muscle strength and endurance in the lower extremities of older people.

Methods

Twenty one long term older TC practitioners were compared with 18 regular older joggers and 22 sedentary counterparts. Maximum concentric strength of knee flexors and extensors was tested at angular velocities of 30°/s and 120°/s. Ankle dorsiflexors and plantar flexors were tested at 30°/s and the dynamic endurance of the knee flexors and extensors was assessed at a speed of 180°/s.

Results

The differences in the muscle strength of the knee joint amongst the three experimental groups were significant at the higher velocity. The strengths of knee extensors and flexors in the control group were significantly lower than those in the jogging group and marginally lower than those in the TC group. For the ankle joint, the subjects in both the TC and jogging groups generated more torque in their ankle dorsiflexors. In addition, the muscle endurance of knee extensors was more pronounced in TC practitioners than in controls.

Conclusion

Regular older TC practitioners and joggers showed better scores than the sedentary controls on most muscle strength and endurance measures. However, the magnitude of the exercise effects on muscles might depend on the characteristics of different types of exercise.     

The CT Evaluation of Neoarytenoid Soft Tissue after an Arytenoidectomy during a Supracricoid Partial Laryngectomy

Objective

To evaluate the postoperative laryngeal CT findings of neoarytenoid soft tissue at an arytenoidectomy site during a supracricoid partial laryngectomy, and to compare its thickness to the mucosa over the spared arytenoid cartilage.

Materials and Methods

Thirty-one patients underwent a supracricoid partial laryngectomy with (n = 14) or without (n = 17) an arytenoidectomy. A postoperative laryngeal CT examination was performed to statistically compare the thickness of the neoarytenoid soft tissue to the mucosa over the spared arytenoids.

Results

The neoarytenoid soft tissue revealed an eccentric prominence in all 14 arytenoidectomy sites. Further, the neoarytenoid soft tissue was consistently thicker than the mucosa over spared arytenoids cartilage (p < 0.01), however did not exceed 11 mm.

Conclusion

The eccentric prominence of neoarytenoid soft tissue at the arytenoidectomy site during a supracricoid partial laryngectomy should be identified and distinguished from a recurrent mass when compared to spared arytenoid cartilage on a postoperative laryngeal CT.     

Biomechanics of running with rocker shoes

Objectives

Load reduction is an important consideration in conservative management of tendon overuse injuries such as Achilles tendinopathy. Previous research has shown that the use of rocker shoes can reduce the positive ankle power and plantar flexion moment which might help in unloading the Achilles tendon. Despite this promising implication of rocker shoes, the effects on hip and knee biomechanics remain unclear. Moreover, the effect of wearing rocker shoes on different running strike types is unexplored. The aim of this study was to investigate biomechanics of the ankle, knee and hip joints and the role of strike type on these outcomes.