The Influence of a Multistage Mountain-Bike Race on Neuromuscular Activation and Synergies: A Case Study

INTRODUCTION

This case study aimed to describe potential changes in neuromuscular activation and synergies after an 8-day cross-country mountain-bike stage race.

METHODS

A peak power output test was performed 5 days before the race. Two days before the start and after 7 days of racing, the athlete performed a power-based Lamberts Submaximal Cycling Test, including surface electromyography, and completed a Daily Analysis of Life Demands of Athletes questionnaire. Neuromuscular activation, in terms of root mean square, timing (onset-offset) of muscle activation, and synergies, was obtained from electromyography recordings.

RESULTS

The athlete reported an increase in symptoms of experienced stress after the stage race on the Daily Analysis of Life Demands of Athletes questionnaire. Both biceps femoris and tibialis anterior muscles showed a reduction in normalized amplitude after the stage race. In addition, the number of synergies that was necessary to describe neuromuscular activation increased from 2 to 3.

CONCLUSIONS

In this case study, the increase in synergies suggests that, after the stage race, the athlete showed a more complex muscle-recruitment pattern. This may indicate that muscle coordination can change when muscle fatigue occurs; however, further research is needed to confirm these results in a larger sample.

Reliability of recovery heart rate variability measurements as part of the Lamberts Submaximal Cycle Test and the relationship with training status in trained to elite cyclists

PURPOSE

To determine if post-exercise heart rate variability, in the form of logged transformed root mean square of successive differences of the R-R intervals (LnRMSSD) can be measured reliably during the recovery from a submaximal cycle test and what the relationship of LnRMSSD is with training status of the cyclists.

METHODS

Fourteen male cyclists participated in the reliability part for the study, which included performing six Lamberts Submaximal Cycle Test (LSCT), during which recovery LnRMSSD was measured over 30 s (LnRMSSD30 s), 60 s LnRMSSD60 s)and 90 s LnRMSSD90 s). In addition, fifty male and twenty female cyclists completed a peak power output (PPO) test (including VO2peak) and 40 km time trial (40 km TT) before which they performed the LSCT as a standardized warm-up. Relationships between the LnRMSSD and PPO, VO2peak and 40 km TT time were studied.

RESULTS

Due to the design of the LSCT, submaximal heart and breathing rate were similar at the end of stage 3 of the LSCT, as well as during the recovery periods. The highest reliability was found in LnRMSSD60 s (ICC: 0.97) with a typical error of the measurement (TEM: 5.8%). In line with this the strongest correlations were found between LnRMSSD60 s and PPO (r = 0.93[male]; 0.85[female]), VO2peak (r = 0.71[male]; 0.63[female];) and 40 km TT (r = - 0.83[male]; - 0.63[female]).

CONCLUSIONS

LnRMSSD60 s can be measured reliably after the LSCT and can predict PPO, VO2peak and 40 km TT performance well in trained-to-elite cyclists. These findings suggest that recovery LnRMSSD can potentially play an important role in monitoring and fine-tuning training prescriptions in trained-to-elite cyclists.

The role of the relative age effect on talent identification in professional road cycling

This study aims to investigate the presence of the relative age effect (RAE) in (semi-)professional cycling, especially within selecting cyclists for Continental (CT) development teams. Data were collected from www.procyclingstats.com (PCS). Cyclists out of the top-25 countries of the PCS ranking that were part of a CT team between 2005 and 2016 and born between January 1986 and December 1997 were included (n = 2854). Distributions of cyclists in different birth quarters (Q1, Q2, Q3 and Q4) as well as for different starting years at CT level (U23_year1, U23_year2, U23_year3 and U23_year4) and reaching professional level or not were investigated using the Chi-square goodness-of-fit test. A RAE was found for cyclists that did not reach professional level, which can be explained by cyclists starting at CT level U23_year1 and U23_year2 (19 and 20 years old). Meaning that for cyclists at 19 and 20 years old, there is a selection bias towards relatively older (Q1) cyclists at the expense of relatively younger (Q4) cyclists. Within the cyclists that reached professional level, no RAE was found, indicating that the RAE diminishes at professional level. This study provides insight into possible selection errors while selecting cyclists for CT development teams.

Demands of professional female cycling races: influence race level and race duration (single or multi-day events)

AbstractThis study is governed by two aims: firstly, expanding the meagre knowledge store regarding the demands set by professional female road cycling and, secondly, ascertaining whether these demands vary in relation to different race-levels and race duration (single- or multi-day events). A total of 1 349 female professional road races was analyzed and demands (intensity, load and performance) were determined. Races were classified based on race level (i.e. Women's World Tour [WWT], level.1 and level.2 according to the International Cycling Federation) and race duration (single- or multi-day events). Differences were assessed with a multilevel random intercept model whilst the strength of said differences were indicated by Cohens'd (0-0.19 trivial; 0.20-0.59 small; 0.60-1.1.9 moderate; 1.20-1.99 large; ≥2.00 very large). In general, no moderate differences for load and intensity were noted for the different race levels. This result contrasts with data obtained from male road cycling. Moderate higher 3 and 5 min maximal mean power (MMP) values were noted in the WWT compared to Level.2 races. More substantial differences were found to exist between single- and multi-day races with single-day races presenting small to large higher load and intensity values. In addition, single-day races presented higher MMPs overall durations (5sec - 60 min) although these differences can be rated trivial to small. This study contributes to the limited knowledge store describing demands in professional female cycling. The reported data provide valuable insights which may aid practitioners and/or coaches in preparing female professional cyclists for races.

Evaluation of host biomarkers for monitoring treatment response in spinal tuberculosis: A 12-month cohort study

BACKGROUND

Monitoring treatment response is an important precaution in spinal tuberculosis (TB), particularly when the condition was clinically diagnosed rather than bacteriologically confirmed and when drug susceptibility testing was not performed. Conventional monitoring measures have limitations and there is a need for favourable alternatives. Therefore, this study aimed to investigate changes in immune biomarkers over the course of treatment for spinal TB and to compare these responses to the conventional monitoring measure, erythrocyte sedimentation rate (ESR).

METHODS

Patients with spinal TB were recruited from a tertiary hospital in the Western Cape, South Africa, and provided blood samples at 0, 3, 6, 9 and 12 months of TB treatment. Blood samples were analysed for ESR, using standard techniques, and for 19 cytokines, using a multiplex platform. Changes in ESR and cytokine levels were investigated using a mixed model ANOVA and Least Significant Difference post-hoc testing.

RESULTS

Twenty-six patients with spinal TB were included in the study although only fifteen remained in follow-up at 12 months. Seven biomarkers changed significantly over the course of treatment (CRP, Fibrinogen, IFN-γ, Ferritin, VEGF-A, ApoA1 and NCAM, p < 0.01) with a further three showing a strong trend towards change (CCL1, CXCL9 and GDF-15, 0.05 ≥ p ≤ 0.06). Responsive biomarkers could be approximately grouped according to patterns of progressive, initial or delayed change. ESR performed similarly to CRP, Fibrinogen and IFN-γ with all showing significant decreases between 0, 6 and 12- months of treatment. Individual ESR responses were variable.

DISCUSSION

Individual ESR responses may be unreliable and support the investigation of multi-marker approaches to evaluating treatment response in spinal TB. Biomarkers of treatment response identified in the current study require validation in a larger study, which may also incorporate aspects such as evaluating biomarkers within the first week of treatment and the inclusion of a healthy control group.

Introducing a Method to Quantify the Specificity of Training for Races in Speed Skating

ABSTRACT

Roete, AJ, Stoter, IK, Lamberts, RP, Elferink-Gemser, MT, and Otter, RTA. Introducing a method to quantify the specificity of training for races in speed skating. J Strength Cond Res XX(X): 000-000, 2022-The specificity of training for races is believed to be important for performance development. However, measuring specificity is challenging. This study aimed to develop a method to quantify the specificity of speed skating training for sprint races (i.e., 500 and 1,000 m), and explore the amount of training specificity with a pilot study. On-ice training and races of 10 subelite-to-elite speed skaters were analyzed during 1 season (i.e., 26 weeks). Intensity was mapped using 5 equal zones, between 4 m·s-1 to peak velocity and 50% to peak heart rate. Training specificity was defined as skating in the intensity zone most representative for the race for a similar period as during the race. During the season, eight 500 m races, seven 1,000 m races, and 509 training sessions were analyzed, of which 414 contained heart rate and 375 sessions contained velocity measures. Within-subject analyses were performed. During races, most time was spent in the highest intensity zone (Vz5 and HRz5). In training, the highest velocity zone Vz5 was reached 107 ± 28 times, with 9 ± 3 efforts (0.3 ± 0.1% training) long enough to be considered 500 m specific, 6 ± 5 efforts (0.3 ± 0.3% training) were considered 1,000 m specific. For heart rate, HRz5 was reached 151 ± 89 times in training, 43 ± 33 efforts (1.3 ± 0.9% training) were considered 500 m specific, and 36 ± 23 efforts (3.2 ± 1.7% training) were considered 1,000 m specific. This newly developed method enables the examination of training specificity so that coaches can control whether their intended specificity was reached. It also opens doors to further explore the impact of training specificity on performance development.

A prospective randomized controlled trial comparing plating augmented with coracoclavicular fixation and hook plate fixation of displaced distal-third clavicle fractures

BACKGROUND

Two popular methods used to treat distal-third clavicle fractures are the traditional hook plate and the anatomically contoured locking plate. No consensus exists on whether one method is more effective than the other. Therefore, the aim of this study was to compare the efficacy of a traditional hook plate with that of an anatomically contoured locking plate augmented with coracoclavicular fixation in the treatment of distal-third clavicle fractures.

METHODS

Enrolled patients were randomly assigned to either the hook plate group (n = 13) or the locking plate group (n = 17). Follow-up assessments (clinical and radiologic) were performed at 6 and 12 months postoperatively.

RESULTS

In both groups, union was achieved in 91% of cases at 6 months and 100% at 12 months. No differences in Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley shoulder scores were noted between the hook plate and locking plate groups at 12 months. From 6 to 12 months, DASH scores improved in the hook plate group (P = .007) and Constant-Murley shoulder scores tended to improve (P = .075). Surgical time was longer in the locking plate group than in the hook plate group (P < .001).

CONCLUSION

Similar functional outcomes and union rates were achieved in both groups at 12 months postoperatively. However, the improvement in DASH scores in the hook plate group from 6 to 12 months suggests that patients treated with an anatomically contoured locking plate make a quicker recovery than patients treated with a hook plate.

The Effects of Visual Feedback on Performance in Heart Rate- and Power-Based-Tasks during a Constant Load Cycling Test

Performance feedback can be essential for cyclists to help with pacing their efforts during competitions and also during standardized performance tests. However, the choice of feedback options on modern bike computers is limited. Moreover, little research on the effectiveness of the currently used feedback methods is available. In this study, two novel feedback variants using a bar or a tacho to visualize targets and deviation from targets were compared to a classic design using only numbers. Participants (6 female and 25 male trained to well-trained athletes) completed a protocol consisting of three heart rate-based tasks and one power-based task. The displays were compared with respect to their ability to guide athletes during their trials. Results showed lower root mean square error (RMSE) of the novel variants, but no significant effect of feedback variant on RMSE was found for both tasks (p > 0.05). However, when comparing the feedback variants on a person to person basis, significant differences were found for all investigated scenarios (p < 0.001). This leads to the conclusion that novel feedback variants can improve athletes' ability to follow heart rate-based and power-based protocols, but even better results might be achieved by individualizing the feedback.

Gait status 26-35 years after selective dorsal rhizotomy: A 9 year follow up study

BACKGROUND

Although the short-term outcomes of selective dorsal rhizotomy (SDR) in children with cerebral palsy (CP) have been well documented, less is known about the long-term benefits of SDR, especially while aging.

RESEARCH QUESTION

Does the gait of adults with CP, who underwent SDR in childhood, change during a nine-year aging follow-up period? Do associations exists between the gait deviation index (GDI) and contextual factors at follow-up?

METHODS

Three-dimensional motion data was captured (Vicon system) of 26 adults (10 female) with CP and spastic diplegia at baseline (17-to-26 years post-SDR) and at nine-year follow-up (26-to-35 years post-SDR), as well as 41 matched typically developed (TD) adults used for reference data. Kinematic, non-dimensional temporal distance and GDI parameters were determined, and associations with contextual factors were studied.

RESULTS

At follow-up the adults with CP had a (median [interquartile ranges]) age of 35.8 [34.2-41.2] years and classified as Gross Motor Function Classification System (GMFCS) level I (n = 13), level II (n = 10) and level III (n = 3). Overall no clinically relevant change in gait quality (GDI) was detected over the nine-year follow-up period. However, small changes were found in hip and knee range of motion, peak knee flexion and walking speed. In line with the baseline study, a number of gait parameters were different to TD adults. The only association found was between GDI and GMFCS at follow-up (r = 0.64, p < 0.01).

SIGNIFICANCE

The overall walking pattern of the adults with CP who underwent SDR in childhood was characterised by mild crouch gait with minimal signs of spasticity, confirming former physical examination findings. Some small changes in certain gait parameters were determined, though clinically the gait quality remained stable during the nine-year aging period. This finding supports the stability of the gait pattern during mid-life in adults with CP, who met the strict SDR selection criteria.

Candidate Biomarkers to Distinguish Spinal Tuberculosis From Mechanical Back Pain in a Tuberculosis Endemic Setting

Background

Spinal tuberculosis (TB) may have a variable, non-specific presentation including back pain with- or without- constitutional symptoms. Further tools are needed to aid early diagnosis of this potentially severe form of TB and immunological biomarkers may show potential in this regard. The aim of this study was to investigate the utility of host serum biomarkers to distinguish spinal TB from mechanical back pain.

Methods

Patients with suspected spinal TB or suspected mechanical back pain were recruited from a tertiary hospital in the Western Cape, South Africa, and provided a blood sample for biomarker analysis. Diagnosis was subsequently confirmed using bacteriological testing, advanced imaging and/or clinical evaluation, as appropriate. The concentrations of 19 host biomarkers were evaluated in serum samples using the Luminex platform. Receiver Operating Characteristic (ROC) curves and General Discriminant Analysis were used to identify biomarkers with the potential to distinguish spinal TB from mechanical back pain.

Results

Twenty-six patients with spinal TB and 17 with mechanical back pain were recruited. Seven out of 19 biomarkers were significantly different between groups, of which Fibrinogen, CRP, IFN-γ and NCAM were the individual markers with the highest discrimination utility (Area Under Curve ROC plot 0.88-0.99). A five-marker biosignature (CRP, NCAM, Ferritin, CXCL8 and GDF-15) correctly classified all study participants after leave-one-out cross-validation.

Conclusion

This study identified host serum biomarkers with the potential to diagnose spinal TB, including a five-marker biosignature. These preliminary findings require validation in larger studies.

Spinal Curvatures, Deformities, and the Level of Disability in People with Bilateral Spastic Cerebral Palsy Living in South Africa; A 6-Year Follow-Up Study During Adulthood

OBJECTIVE

Determine if spinal curvatures, deformities, as well as level of disability (due to back pain) changes with aging in adults with bilateral spastic cerebral palsy after receiving orthopedic interval surgery approach treatment in childhood.

DESIGN

Consecutive case-series SETTING: Urban South Africa PARTICIPANTS: Twenty-seven ambulatory adults with cerebral palsy MAIN OUTCOME MEASURES: Spinal curvatures (scoliosis, thoracic kyphosis and lumbar lordosis) and deformities (spondylolysis and spondylolisthesis) were determined with X-rays, while the level of disability was assessed with the Oswestry Disability Index.

RESULTS

The prevalence of spinal abnormalities were: 30% scoliosis (mild: <30°), 0% thoracic hyperkyphosis, 15% lumbar hyperlordosis, 0%; spondylolysis, and 0% spondylolisthesis. No changes in scoliosis and lumbar lordosis angles were observed, while the change in thoracic kyphosis angle was smaller than the minimal clinically important difference and moved closer toward the norm-values for typically developing adults. Level of disability remained similar with 63% reporting minimal disability, 26% moderate disability and 11% severe disability. No associations with spinal curvatures were found.

CONCLUSIONS

No clinically meaningful changes in spinal curvatures, deformities and level of disability due to pain were seen during the 6 years follow-up period in adults with cerebral palsy who have been treated with interval surgery approach in childhood.

Differences in execution and perception of training sessions as experienced by (semi-) professional cyclists and their coach

This study aimed to investigate whether (semi-)professional cyclists' execution of a training programme differs from the coach's designed training programme. Also, the study sought to ascertain, in instances where the training sessions were indeed executed as designed by the coach, whether the perception of the cyclists differed from the intention of the coach. This study highlights the differences between the coach and the individual cyclist. In total, 747 training sessions were collected from 11 (semi-)professional cyclists. Rating of Perceived Exertion (RPE) and session Rating of Perceived Exertion (sRPE) were compared with intended RPE (iRPE) and intended sRPE (isRPE), planned by the coach. Pearson's correlation, regression coefficients and Typical Error of Estimate (TEE) were used to identify differences between the executed and planned training sessions. Moderate to large TEEs were noted between executed and intended sRPE, which indicates that cyclists do not always execute the training programme planned by the coach. Furthermore, when the training was executed as planned by the coach, very large correlations but moderate to very large TEEs were noted between cyclists' (s)RPE and the coach's i(s)RPE, with unique individual regression coefficients. This indicates that the relationship between RPE and iRPE is unique to each cyclist. Both the different execution and perception of the training programme by the individual cyclists could cause an impaired training adaptation. Therefore, the coach must pay attention to the perception of training sessions by the individual cyclist. Improved individual management of training load could result in the optimisation of the proposed training programme.Highlights On individual level, (semi-)professional cyclists train differently than planned by the coach, based on duration and sRPE of the training sessionsThe relationship between the RPE of the cyclist and the iRPE of the coach is unique for each cyclistCoaches should be aware that cyclist and coach could interpret the same training differently, resulting in an easier perception of low- and high- intensity training sessions by the cyclists compared to the intention of the coach.

More than 25 years after selective dorsal rhizotomy: physical status, quality of life, and levels of anxiety and depression in adults with cerebral palsy

OBJECTIVE

The primary purpose of selective dorsal rhizotomy (SDR) is to ameliorate spasticity in the lower extremities of children with cerebral palsy (CP). In correctly selected patients, this neurosurgical procedure has been shown to have a beneficial effect on many aspects of the child's life. However, given the challenges faced by adults with CP, it would be valuable to document the status of this population compared to their peers later in adulthood. Therefore, the aim of this study was to determine the physical status, mental health, and health-related quality of life (HRQoL) of adults with CP who underwent SDR at least 25 years ago, compared to matched typically developing (TD) individuals. The second aim was to investigate relationships between physical status and the other outcome measures.

METHODS

Adults with CP were recruited from a database of children who had undergone SDR performed using the technique introduced by Professor Warwick Peacock at Red Cross War Memorial Children's Hospital in Cape Town, South Africa, between 1981 and 1991. These individuals were matched for age, sex, body mass index, and socioeconomic status to a TD adult cohort from a similar background. The parameters assessed were lower-extremity muscle tone, passive range of motion, muscle strength, selectivity, functional mobility and dynamic balance (Timed Up and Go [TUG] test), HRQoL (SF-36), and anxiety and depression levels.

RESULTS

Twenty-six adults with CP who had a median age of 35.8 years (interquartile range 34.2-41.4 years) (female/male: n = 10/16; Gross Motor Function Classification System level I/II/III: n = 13/10/3), were compared to 26 TD adults. Muscle tone was similar, whereas passive range of motion, muscle strength, selectivity, TUG, and SF-36 physical functioning (concept and summary) scores differed between the cohorts. Other SF-36 parameters, anxiety levels, and depression levels were not different. Strong correlations were found between the muscle strength and TUG scores.

CONCLUSIONS

Normalized lower-extremity muscle tone was sustained 25-35 years after SDR. Whereas the lower scores for physical assessments are in line with findings in other CP populations, remarkably, relatively good mental health and HRQoL scores were reported in this CP group despite their physical limitations. The strong correlation between muscle strength and TUG suggests that strength training after SDR may have value in improving functional mobility and balance.

Maintaining Power Output with Accumulating Levels of Work Done Is a Key Determinant for Success in Professional Cycling

INTRODUCTION

This study aimed to investigate if performance measures are related to success in professional cycling and to highlight the influence of prior work done on these performance measures and success.

METHODS

Power output data from 26 professional cyclists, in a total of 85 seasons, collected between 2012 and 2019, were analyzed. The cyclists were classified as "climber" or "sprinter" and into category 1 (CAT.1; ≥400 PCSpoints (successful)) and CAT.2 (<400 PCSpoints (less successful)), based on the number of procyclingstats-points (PCSpoints) collected for that particular season. Maximal mean power outputs (MMP) for 20 min, 5 min, 1 min, and 10 s relative to body weight for every season were determined. To investigate the influence of prior work done on these MMP values, six different levels of completed work done were determined, which are based on the amount of completed kilojoules per kilogram (0, 10, 20, 30, 40, and 50 kJ·kg-1). Subsequently, the decline in MMP for each duration (if any) after each level of completed work done was evaluated.

RESULTS

Mixed model revealed that prior work done affects the performance of climbers and sprinters negatively. However, CAT.1 climbers have a smaller decline in 20- and 5-min MMP after high amounts of work done compared with CAT.2 climbers. Similarly, CAT.1 sprinters have a smaller decline in 10-s and 1-min MMP after high amounts of work done compared with CAT.2 sprinters.

CONCLUSIONS

It seems that the ability to maintain high MMP (corresponding with the specialization of a cyclist) after high amounts of work done (i.e., fatigue) is an important parameter for success in professional cyclists. These findings suggest that assessing changes in MMP after different workloads might be highly relevant in professional cycling.

Biomarkers to predict FDG PET/CT activity after the standard duration of treatment for spinal tuberculosis: An exploratory study

OBJECTIVES

18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography- Computed Tomography (PET/CT) scans can be used to assess healing following treatment for spinal tuberculosis (TB) but have limited accessibility and high cost. This study investigated the association between immune biomarkers and FDG-PET/CT activity after ≥9 months of treatment for spinal TB.

METHODS

Patients who had completed ≥9 months of treatment for spinal TB were recruited from a major hospital in the Western Cape, South Africa. Participants underwent a FDG-PET/CT scan and FDG- PET/CT activity was quantified for all spinal and extra-spinal sites. Participants also provided a blood sample, which was evaluated for 19 cytokines along with erythrocyte sedimentation rate (ESR). Correlations and multiple regression analyses were used to investigate the association between biomarkers and PET/CT measures.

RESULTS

Twenty-eight patients were recruited, of whom 24 (86%) had spinal and/or extra-spinal FDG-PET/CT activity. In the strongest multiple regression model, CXCL10/IP-10, VEGFA, IFN-γ, CRP and Factor D/Adipsin explained 52% of the variation in overall maximal FDG uptake. Conventional monitoring marker ESR showed no significant association with PET/CT measures.

CONCLUSIONS

The current findings offered encouragement that biomarkers to predict FDG-PET/CT activity may show some promise and identified candidate biomarkers for further investigation in this regard.

Adults with spastic diplegic cerebral palsy living in a low-to-middle income Country: A six-year follow-up study on pain, functional mobility, activity and participation

BACKGROUND

Insight into the day-to-day challenges faced by adults living with Cerebral Palsy (CP) in low-to-middle income countries (LMICs) will enable support towards healthy ageing in this population.

OBJECTIVES

To determine changes in level of pain, functional mobility and accomplishment as well as satisfaction in daily life of ambulant adults with CP living in a LMIC over a six-year period, compared to typically developed (TD) adults. In addition, to determine associations with individual characteristics.

METHODS

Twenty-eight adults with CP and spastic diplegia (median [interquartile ranges] age = 39.0 [34.0-45.7] years; Gross Motor Function Classification System level I/II/III: n = 11/12/5) participated in this study, together with 28 matched TD adults. Levels of accomplishment and satisfaction were assessed with the Life-Habits questionnaire, functional mobility was determined with the Functional Mobility Scale and (back, lower and upper limb) pain frequency was gauged with a standardized questionnaire.

RESULTS

Life-Habits accomplishment and satisfaction scores of adults with CP remained unchanged during the six-year follow-up, with 79% being independent and 100% satisfied. Functional mobility decreased and related to the total accomplishment score. No change in pain frequency was observed, but adults with CP experienced more pain than their peers. Back pain was significantly associated with the total satisfaction score.

CONCLUSIONS

Relative high levels of accomplishment and satisfaction and no change in pain frequency were noted during a six-year follow-up study of adults with CP living in a LMIC. The importance of exercise/rehabilitation programs to reduce pain and maintain functional mobility in persons ageing with CP was highlighted.

Analysis of a Submaximal Cycle Test to Monitor Adaptations to Training: Implications for Optimizing Training Prescription

ABSTRACT

Capostagno, B, Lambert, MI, and Lamberts, RP. Analysis of a submaximal cycle test to monitor adaptations to training: Implications for optimizing training prescription. J Strength Cond Res 35(4): 924-930, 2021-The Lamberts and Lambert Submaximal Cycle Test (LSCT) was developed to monitor training adaptation to optimize the training prescription of cyclists. However, it is not known which of the variables within the LSCT are most closely associated with changes in training status. The aim of this study was to retrospectively analyze the LSCT data of cyclists (n = 15) who completed a 2-week high-intensity interval training intervention. The cyclists were retrospectively allocated to 1 of 2 groups based on the change in their 40-km time trial (40-km TT) performance. The "adapters" (n = 7) improved their 40-km TT performance, while the "nonadapters" (n = 8) failed to improve their 40-km TT performance. The variables measured in the LSCT were analyzed to determine which measures tracked the improvements in 40-km TT performance the best. Heart rate recovery increased significantly during the training period in the "adapters" group, but decreased in the "nonadapters" group. Mean power output in stage 2 of the LSCT tended to increase during the high-intensity interval training period in the "adapters" group and was unchanged in the "nonadapters" group. The findings of this study suggest that heart rate recovery and mean power output during stage 2 are the most sensitive markers to track changes in training status within the LSCT.

A long-term follow-up study of spinal abnormalities and pain in adults with cerebral palsy and spastic diplegia more than 25 years after selective dorsal rhizotomy

OBJECTIVE

The main purpose of selective dorsal rhizotomy (SDR) is to reduce spasticity in the lower extremities of children diagnosed with cerebral palsy (CP) and spastic diplegia. The potential for developing spinal abnormalities and pain is a concern, especially in the aging CP population. Therefore, the aim of this study was to evaluate spinal abnormalities, level of pain, and disability (due to back or leg pain) in adults with CP, and associations with participant characteristics, more than 25 years after SDR.

METHODS

This is a 9-year follow-up study with data collection conducted in 2008 and 2017. Radiographs were assessed for the degree of scoliosis, thoracic kyphosis and lumbar lordosis curvatures, and prevalence of spondylolysis and spondylolisthesis, while level of pain and disability was determined with a self-developed questionnaire and the Oswestry Disability Index (ODI) questionnaire, respectively.

RESULTS

Twenty-five participants were included (15 males; median age 35.9 years, IQR 34.3-41.5 years), with a follow-up time after SDR ranging from 25 to 35 years. No clinically relevant changes were found for spinal curvatures, spondylolysis and spondylolisthesis, perceived pain frequency, and ODI scores between 2008 and 2017. While the prevalence of spondylolysis was 44%, spondylolisthesis was found in 20% (of whom 15% were grade I and 5% grade II), lumbar hyperlordosis was found in 32%, thoracic hyperkyphosis in 4%, and scoliosis in 20%. The Cobb angle was < 25°, and no patient required surgery for scoliosis. In addition, the low back was reported as the most common site of pain, with 28% of the adults with CP having daily pain. This resulted in 80% of the cohort indicating none or minimal disability due to pain based on the ODI. The only correlation found was between hyperkyphosis and female gender.

CONCLUSIONS

At follow-up more than 25 years after SDR, no progression in spinal abnormalities, level of pain, and disability was found when compared with findings 15 years after SDR. The prevalence of scoliosis, thoracic hyperkyphosis, and lumbar hyperlordosis was within the range reported for adults with CP, while spondylolysis and spondylolisthesis occurred more often than would be expected. It is difficult, however, to establish the role of SDR in this finding, given the limited data on the natural history of CP. Despite the encouraging outcome of this long-term follow-up study after SDR, it is important to continue monitoring adults with CP during the aging process.

Muscular Activation Patterns During Exercise on the Treadmill, Stepper, and Elliptical Trainer

Eken, MM, Withers, A, Flanagan, K, Burger, J, Bosch, A, and Lamberts, RP. Muscular activation patterns during exercise on the treadmill, stepper, and elliptical trainer. J Strength Cond Res XX(X): 000-000, 2020-Because of the low-impact, the stepper and elliptical trainer are popular alternatives to running when runners sustain running-related injuries. Muscular effort is expected to be lower during exercise on the stepper and elliptical trainer compared with running. The aim of this study was to quantify this by comparing muscular effort when exercising at similar moderate-to-high exercise intensities on a treadmill, stepper, and elliptical trainer. Seventeen well-trained runners (V[Combining Dot Above]O2max: 53.3 ml·min·kg [male: n = 9], 44.8 ml·min·kg [female: n = 8]; average peak treadmill running speed: 18.7 km·h [male], 16.3 km·h [female]) performed exercise at submaximal levels (60%-70%-80% of peak workload) on the treadmill, stepper, and elliptical trainer. Peak workload was determined during peak exercise tests on separate days. Surface electromyography was recorded from lower extremity muscles. Root-mean-squared (RMS) values were calculated and compared between exercise modalities and submaximal levels. Significance was set at p < 0.05. Root-mean-squared levels of lower extremity muscles were significantly reduced during exercise on the stepper and elliptical trainer compared with treadmill running (p < 0.05, except for quadriceps (p > 0.05). Overall, similar RMS levels were found on stepper and elliptical trainer (p > 0.05), whereas in several cases higher RMS levels were found on the stepper compared with elliptical trainer (p < 0.05). These findings support clinical expectations that exercise on the stepper and elliptical trainer reduces muscular effort up to 60% compared with (treadmill) running, and therefore can be effective training modalities during rehabilitation from running-related injuries by restricting impact on lower extremities.

The level of accomplishment and satisfaction in activity and participation of adults with cerebral palsy and spastic diplegia

BACKGROUND

Orthopaedic surgery is commonly performed in children with cerebral palsy (CP) and spastic diplegia to improve functional mobility. However, no research has quantified levels of accomplishment and satisfaction in daily activities and participation long-term after surgery. Therefore, this study aimed to investigate 1) the level of accomplishment and satisfaction of life habits in adults with CP, 2) whether there were differences between Gross Motor Function Classification System (GMFCS) levels, and 3) associations with contextual factors, functional level and frequency of pain.

METHODS

Levels of accomplishment and satisfaction in activity and participation were assessed using the Life-Habits 3.1 questionnaire in 30 adults with CP and spastic diplegia who received the first orthopaedic intervention more than 15 years ago (age: median [interquartile range (IQR)] = 27:8 [21:7-33:8] y:mo; GMFCS level I/II/III: n = 15/11/4). GMFCS and Functional Mobility Scale (FMS) assessed mobility over 5 m, 50 m and 500 m. Participants reported frequency of back pain and pain in the lower and upper limb.

RESULTS

On average 63% of the participants were independent and faced no difficulties in the accomplishment of all life habits. Difficulties were mostly experienced for 'mobility', 'housing' and 'recreation' (all 61%). Participants were overall satisfied, with lowest scores for 'employment' (13% dissatisfied). Between the GMFCS levels, accomplishment scores of participants with level I were significantly higher than level II. In addition, negative associations were found between accomplishment of life habits and GMFCS level, FMS, and pain on spinal level.

CONCLUSION

Levels of accomplishment and satisfaction were relatively high among adults with CP who underwent orthopaedic interventions during childhood. However, negative associations between accomplishment levels and level of functioning and back pain argue for rehabilitation programs specialized on these factors. This information is imperative for physicians and allied health care professionals to guide adults with CP during ageing.

Short-term outcomes of submuscular bridge plating of length-unstable paediatric femoral shaft fractures in children - Insights from a South African tertiary hospital setting

ABSTRACT BACKGROUND: Femoral diaphyseal fracture is a common paediatric orthopaedic injury; however, the management of these fractures remains controversial in children between the ages of 6 and 13 years. The preferred approach for children appears to be surgical, enabling early mobilisation. Some studies have reported that submuscular bridge plating (SBP) might be a good alternative treatment method with favourable outcomes. The aim of this study was to determine whether SBP a) leads to union in length-unstable fractures with a low complication rate; b) leads to reasonable alignment and leg length equality; and c) has acceptable clinical outcomes in a South African tertiary hospital setting. METHODS: All patients with predominantly length-unstable femoral diaphyseal fractures who were treated between 1 January 2011 and 31 December 2012 were included in this study. Patients were treated with SBP using standard of care techniques, and hardware removal was performed at approximately eight months post-operatively. The nine months post-operative assessment between the affected and unaffected leg was used to assess the effectiveness of the SBP intervention RESULTS: A total of 29 patients (mean age 9±2 years) were included. The majority of the fractures (n=27, 93%) were length-unstable. Two patients (7%) had transverse fractures with >2 cm overlap and/or weighing >45 kg. All fractures healed within expected time frames. No overall leg length discrepancy (p=0.94) or coronal mechanical axis deviation (p=0.51) was observed between the affected and unaffected lower limbs at nine months post-surgery. No differences between the operated and non-operated sides were observed for hip flexion (p=0.88), hip external rotation (p=0.36), hip internal rotation (p=0.12) or knee flexion (p=0.96 CONCLUSION: SBP provides reliable outcomes in children with diaphyseal femoral fractures and is our preferred method of fixation for a) length-unstable fractures; b) fractures close to the metaphysis; and c) children weighing more than 45 kg Level of evidence: Level 4 Keywords: femoral fractures, paediatric, orthopaedic surgery, children

Lower Extremity Strength Profile in Ambulatory Adults with Cerebral Palsy and Spastic Diplegia: Norm Values and Reliability for Hand-Held Dynamometry

BACKGROUND

The handheld dynamometer (HHD) is a well-accepted tool to assess muscle strength in children with cerebral palsy (CP), though reliability is not tested for adults with CP and no normative data are available.

OBJECTIVES

To present strength levels of lower extremity muscle groups and test-retest reliability of HHD measurements in ambulatory adults with CP and typically developed (TD) adults.

DESIGN

Case-control study.

SETTING

Human motion laboratory.

PARTICIPANTS

Fifty-four adults with CP (28 men; Gross Motor Function Classification System [GMFCS] level I/II/III: n = 25/20/9; mean age (SD) = 38 (7) year) and 62 TD adults (31 men; mean age (SD) = 37 (5) year).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Maximum strength levels were obtained during voluntary isometric contraction of eight lower extremity muscle groups in adults with CP and spastic diplegia and TD adults using HHD. Three trials were performed per muscle group per leg. Test-retest reliability was investigated by calculating intraclass correlation coefficient (ICC), coefficient of variation (CV), and typical error of measurement (TEM).

RESULTS

Force and torque levels were significantly lower in all eight lower extremity muscle groups. Excellent ICC levels were observed in TD, GMFCS I and II (>0.90), and moderate to excellent (0.82-0.97) in GMFCS III. CV and TEM were higher in adults with CP compared to TD adults, especially in GMFCS III.

LIMITATIONS

No subtypes other than adults with CP and spastic diplegia were included.

CONCLUSIONS

Lower extremity strength profiles demonstrate substantial muscle weakness in ambulatory adults with CP compared to TD adults, which highlights the importance to address muscle weakness in this population group. These strength profiles may serve as norm values for clinicians and researchers. In addition, HHD showed to be reliable to assess lower extremity strength in adults with CP.

Daily activities, participation, satisfaction, and functional mobility of adults with cerebral palsy more than 25 years after selective dorsal rhizotomy: a long-term follow-up during adulthood

PURPOSE

To determine changes in level of accomplishment and satisfaction in daily activities and social participation, and functional mobility in adults with cerebral palsy (CP) more than 25 years after selective dorsal rhizotomy (SDR).

MATERIALS AND METHODS

This long-term observational nine-year follow-up study included 26 adults (median age 35 years) with CP and spastic diplegia, and 26 matched typically developing adults. Assessment tools used were the Life-Habits questionnaire and the Functional Mobility Scale.

RESULTS

Most of the adults with CP were independent and satisfied with accomplishing life habits and no changes were determined, except for a small change in the Housing accomplishment level. Compared to typically developing adults, the CP cohort was more dependent in accomplishing Mobility and Recreation. However, the level of satisfaction was similar for most life habits except for Mobility. Functional mobility did not change, but correlated with Life-Habits results.

CONCLUSIONS

Adults with CP showed high and stable levels of accomplishment and satisfaction in daily activities and social participation more than 25 years after SDR. This is in contrast with the literature, where functional decline was shown for individuals with CP as they age. The relation with functional mobility highlights the importance to focus the rehabilitation on maintaining walking ability in order to enable high level of daily activities and social participation in adults with CP.Implications for rehabilitationSelective dorsal rhizotomy (SDR) is a valuable treatment option for a selective group of children with cerebral palsy (CP) in order to reduce spasticity.The long-term outcomes of SDR on level of accomplishment and satisfaction in daily activities and social participation as well functional mobility in adults with CP are not clear.More than 25 years after SDR adults with CP experienced stable and lasting high levels of functioning regarding daily activities and social participation and were satisfied with the way they accomplished life habits.Functional mobility was correlated to level of accomplishment and satisfaction in daily activities and social participation, which highlights the importance to focus rehabilitation programs on maintaining functional mobility in order to enable daily activities and social participation in adults with CP.

Bony anatomy of the third metacarpal and relationship with the capitate: a computed tomography study

PURPOSE

The purpose of this study was to accurately establish the anatomical variability of the third metacarpal, its medullary canal, and the relationship with the capitate in the context of high rates of component loosening still seen in total wrist arthroplasty.

METHODS

CT scans of a 100 hands (age: 41 ± 14 years (range: 16-71 years); male/female ratio: 53/47) were studied to establish the detailed anatomy of the third metacarpal and the capitate.

RESULTS

Although the shape of the third metacarpal and the angles formed with the capitate were highly variable, the third metacarpal length was longer in males (p < 0.001), the proximal cortical bone was thicker (p < 0.001) and the sagittal metacarpal-capitate axis offset was greater (p = 0.01). A relationship was found between the total length of the metacarpal and the distance to the isthmus from the base (r = 0.63; p < 0.0001) which was unaffected by gender. No age-related relationships were significant.

CONCLUSION

The anatomy of the third metacarpal and capitate varies considerably more than has been alluded to in current wrist arthroplasty literature. Differences between males and females can likely be attributed to hand size. The distance of the isthmus from the base can be predicted from the total length of the metacarpal with a standard error of 1.9 mm.

The Effectiveness of a Flexible Locked Intramedullary Nail and an Anatomically Contoured Locked Plate to Treat Clavicular Shaft Fractures: A 1-Year Randomized Control Trial

BACKGROUND

Displaced and shortened clavicular shaft fractures can be treated operatively with intramedullary or extramedullary fixation. The aim of the present study was to compare the union rates and functional outcomes of displaced and/or shortened clavicular shaft fractures treated with a flexible locked intramedullary nail or with an anatomically contoured locked plate.

METHODS

Seventy-two patients with acute displaced and/or shortened clavicular shaft fractures underwent randomly assigned management with either an intramedullary locked nail or an anatomically contoured locked plate. The same surgeon performed all surgical procedures, and all patients underwent identical postoperative treatment regimens. Incision length, surgical time, and union rate were recorded, and the functional outcome of the shoulder was assessed with use of the Disabilities of the Arm, Shoulder and Hand (DASH) and Constant Shoulder (CS) scores. Data were analyzed with use of traditional statistical methods as well as Cohen effect sizes, which were based on the minimal clinical important differences.

RESULTS

Thirty-seven patients were managed with an anatomically contoured locked plate, and 35 patients were managed with a Sonoma CRx intramedullary flexible locked nail. There were no differences in general patient characteristics, fracture type, or displacement between treatment groups. The nailing group had significantly better outcomes (p < 0.001) than the locked plating group for surgical time (mean and standard deviation [SD], 45 ± 12 compared with 65 ± 21 minutes, respectively) and incision size (mean and SD, 37 ± 9 compared with 116 ± 18 mm). A union rate of 100% was observed in both groups. DASH scores were similar between groups at 1.5, 3, and 6 months, whereas the nailing group had significantly better DASH scores at 12 months (p = 0.022); however, this difference had only a moderate effect size. Overall, individual variation in DASH and CS scores was substantially higher in the plating group compared with the nailing group.

CONCLUSIONS

Both the precontoured locked plate and the flexible locked intramedullary nail effectively treated displaced and/or shortened clavicular shaft fractures. Similar outcomes were achieved at 1.5, 3, and 6 months after surgical intervention, and better DASH scores were found in the nailing group at 12 months. Cohen effect sizes suggested that slightly better outcomes were potentially achieved in the nailing group.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Running Economy: Neuromuscular and Joint-Stiffness Contributions in Trained Runners

CONTEXT

It is debated whether running biomechanics make good predictors of running economy, with little known about the neuromuscular and joint-stiffness contributions to economical running gait.

PURPOSE

To understand the relationship between certain neuromuscular and spatiotemporal biomechanical factors associated with running economy.

METHODS

Thirty trained runners performed a 6-min constant-speed running set at 3.3 m·s-1, where oxygen consumption was assessed. Overground running trials were also performed at 3.3 m·s-1 to assess kinematics, kinetics, and muscle activity. Spatiotemporal gait variables, joint stiffness, preactivation, and stance-phase muscle activity (gluteus medius, rectus femoris, biceps femoris, peroneus longus, tibialis anterior, and gastrocnemius lateralis and medius) were variables of specific interest and thus determined. In addition, preactivation and ground contact of agonist-antagonist coactivation were calculated.

RESULTS

More economical runners presented with short ground-contact times (r = .639, P < .001) and greater stride frequencies (r = -.630, P < .001). Lower ankle and greater knee stiffness were associated with lower oxygen consumption (r = .527, P = .007 and r = .384, P = .043, respectively). Only  lateral gastrocnemius-tibialis anterior coactivation during stance was associated with lower oxygen cost of transport (r = .672, P < .0001).

CONCLUSIONS

Greater muscle preactivation and biarticular muscle activity during stance were associated with more economical runners. Consequently, trained runners who exhibit greater neuromuscular activation prior to and during ground contact, in turn optimizing spatiotemporal variables and joint stiffness, will be the most economical runners.

Biomechanical analysis of gait waveform data: exploring differences between shod and barefoot running in habitually shod runners

The aim of this study was to utilise one-dimensional statistical parametric mapping to compare differences between biomechanical and electromyographical waveforms in runners when running in barefoot or shod conditions. Fifty habitually shod runners were assessed during overground running at their current 10-km race running speed. Electromyography, kinematics and ground reaction forces were collected during these running trials. Joint kinetics were calculated using inverse dynamics. One-dimensional statistical parametric mapping one sample t-test was conducted to assess differences over an entire gait cycle on the variables of interest when barefoot or shod (p<0.05). Only sagittal plane differences were found between barefoot and shod conditions at the knee during late stance (18-23% of the gait cycle) and swing phase (74-90%); at the ankle early stance (0-6%), mid-stance (28-38%) and swing phase (81-100%). Differences in sagittal plane moments were also found at the ankle during early stance (2, 4-5%) and knee during early stance (5-11%). Condition differences were also found in vertical ground reaction force during early stance between (3-10%). An acute bout of barefoot running in habitual shod runners invokes temporal differences throughout the gait cycle. Specifically, a co-ordinative responses between the knee and ankle joint in the sagittal plane with a delay in the impact transient peak; onset of the knee extension and ankle plantarflexion moment in the shod compared to barefoot condition was found. This appears to affect the delay in knee extension and ankle plantarflexion during late stance. This study provides a glimpse into the co-ordination of the lower limb when running in differing footwear.

Acute fatigue negatively affects risk factors for injury in trained but not well-trained habitually shod runners when running barefoot

INTRODUCTION

Many factors may contribute to running-related injury. These include fatigue and footwear, the combination of which has rarely been studied, in particular with reference to barefoot running, recently advocated as a method to reduce injury risk.

METHODS

Twenty-two runners (12 well-trained and 10 trained) participated in a 10 km fatiguing trial. Knee and ankle joint kinematics and kinetics and electromyography were assessed during overground running in the barefoot and shod condition. This was performed pre- and post-fatigue using a motion capture system and force platforms.

RESULTS

Initial loading rate increased in the trained runners when barefoot but not shod. Shod knee stiffness increased in both groups after fatigue, whereas barefoot knee stiffness decreased only in the trained group. A reduction in barefoot bicep femoris pre-activation was found in both groups. During stance, a reduction in vastus lateralis and biceps femoris and an increase in tibialis anterior activity were found over time in both groups and conditions. Trained runners decreased gluteus medius and increased lateral gastrocnemius median frequency for both conditions after fatigue.

CONCLUSION

When fatigued, gait adjustments in habitually shod runners may increase injury risk when running barefoot. Training status may be a risk factor for injury, as less-trained runners experience muscular fatigue changes that may compromise ground reaction force attenuation. Caution is recommended when transitioning to pure barefoot running.

Habitual Minimalist Shod Running Biomechanics and the Acute Response to Running Barefoot

The aim of the study was to determine whether habitual minimalist shoe runners present with purported favorable running biomechanithat reduce running injury risk such as initial loading rate. Eighteen minimalist and 16 traditionally cushioned shod runners were assessed when running both in their preferred training shoe and barefoot. Ankle and knee joint kinetics and kinematics, initial rate of loading, and footstrike angle were measured. Sagittal ankle and knee joint stiffness were also calculated. Results of a two-factor ANOVA presented no group difference in initial rate of loading when participants were running either shod or barefoot; however, initial loading rate increased for both groups when running barefoot (p=0.008). Differences in footstrike angle were observed between groups when running shod, but not when barefoot (minimalist:8.71±8.99 vs. traditional: 17.32±11.48 degrees, p=0.002). Lower ankle joint stiffness was found in both groups when running barefoot (p=0.025). These findings illustrate that risk factors for injury potentially differ between the two groups. Shoe construction differences do change mechanical demands, however, once habituated to the demands of a given shoe condition, certain acute favorable or unfavorable responses may be moderated. The purported benefits of minimalist running shoes in mimicking habitual barefoot running is questioned, and risk of injury may not be attenuated.

Submaximal Markers of Fatigue and Overreaching; Implications for Monitoring Athletes

The regular monitoring of athletes is important to fine-tune training and detect early symptoms of overreaching. Therefore the aim of this study was to determine if a noninvasive submaximal running test could reflect a state of overreaching. 14 trained runners completed a noninvasive Lamberts Submaximal Running Test, one week before and 2 days after finishing an ultramarathon, and delayed onset of muscle soreness and the daily analysis of life demands for athletes questionnaire were also captured. After the ultramarathon, submaximal heart rate was lower at 70% (-3 beats) and 85% of peak treadmill running speed (P<0.01). Ratings of perceived exertion were higher at 60% (2 units) and 85% (one unit) of peak treadmill running speed, while 60-second heart rate recovery was significantly faster (7 beats, P<0.001). Delayed Onset of Muscle Soreness scores and the number of symptoms of stress (Daily Analysis of Life Demands for Athletes) were also higher after the ultramarathon (P<0.01). The current study shows that the Lamberts Submaximal Running Test is able to reflect early symptoms of overreaching. Responses to acute fatigue and overreaching were characterized by counterintuitive responses, such as lower submaximal heart rates and faster heart rate recovery, while ratings of perceived exertion were higher.

Bone health in elite Kenyan runners

Impact loading in athletes participating in various sports has been positively associated with increased bone mineral density (BMD), but this has not been investigated in elite Kenyan runners. Body composition and site-specific BMD measures quantified with dual x-ray absorptiometry were measured in 15 elite male Kenyan runners and 23 apparently healthy South African males of different ethnicities. Training load and biomechanical variables associated with impact loading, such as joint stiffness, were determined in the elite Kenyan runners. Greater proximal femur (PF) BMD (g · cm^-2) was higher (P = 0.001, ES = 1.24) in the elite Kenyan runners compared with the controls. Six of the 15 (40%) Kenyan runners exhibited lumbar spine (LS) Z-Scores below -2.0 SD, whereas this was not found in the apparently healthy controls. PFBMD was associated with training load (r = 0.560, P = 0.003) and ankle (r = 0.710, P = 0.004) and knee (r = 0.546, P = 0.043) joint stiffness. Elite Kenyan runners exhibit greater PFBMD than healthy controls, which is associated with higher training load and higher joint stiffness. Our results reaffirm the benefits of impact loading on BMD at a weight-bearing site, while a high prevalence of low LSBMD in the elite Kenyan runners is hypothesised to be the result of a mismatch between energy intake and high training load. Future research investigating energy availability in Kenyan runners and the possible association with musculoskeletal injury should be investigated.

HIV encephalopathy with bilateral lower limb spasticity: upper limb motor function and level of activity and participation

AIM

To describe upper limb motor function and level of activity and participation in children with HIV encephalopathy (HIVE) and bilateral lower limb (BLL) spasticity.

METHOD

Thirty ambulant children with HIVE and BLL spasticity and 20 typically developing children, between 5 years and 12 years, were recruited. Upper limb motor function was assessed using the Purdue Pegboard and level of activity and participation using the Computer-Adapted Pediatric Evaluation of Disabilities Inventory (PEDI-CAT).

RESULTS

The HIVE group comprised 14 males and 16 females (mean age [SD] 8y 8mo [2y 2mo], Gross Motor Function Classification System (GMFCS) level I [n=10], II [n=11], and III [n=9]) and the typically developing group comprised 11 males and 9 females (mean age 8y 8mo [2y 3mo]). The HIVE group had lower scores than the typically developing group for all pegboard tasks and three of the four PEDI-CAT domains (p≤0.001). However, individual outcome scores varied substantially within each GMFCS level.

INTERPRETATION

Children with HIVE and BLL spasticity may have significantly poorer upper limb motor performance and lower levels of activity and participation than typically developing children. These findings suggest that an assessment of upper limb motor function should form part of optimal care for this population.

How well can step-off and gap distances be reduced when treating intra-articular distal radius fractures with fragment specific fixation when using fluoroscopy

INTRODUCTION

Although fragment specific fixation has proved to be an effective treatment regime, it has not been established how successfully this treatment could be performed using fluoroscopy and what the added value of arthroscopy could be. Establish gap and step-off distances after in intra-articular distal radius fractures that have been treated with fragment specific fixation while using fluoroscopy.

MATERIAL

Forty-four patients with an intra-articular distal radius fracture were treated with fragment specific fixation while using fluoroscopy.

METHODS

After the treatment of the intra-articular distal radius fracture with fragment specific fixation and the use of fluoroscopy, but before the completion of the surgical intervention, all gap, and step-off distances were determined by using arthroscopy. In addition, the joint was checked for any other wrist pathologies.

RESULTS

Arthroscopy after the surgical intervention showed that in 37 patients no gap distances could be detected, while in six patients a gap distance of≤2mm was found and in one patient, a gap distance of 3mm. Similarly, arthroscopy revealed no step-off distances in 33 patients, while in 11 patients a step-off distance of≤2mm was found. Although additional wrist pathologies were found in 48% of our population, only one patient needed surgical intervention. Three months after the surgical intervention wrist flexion was 41±10°, wrist extension 51±17°, ulnar deviation 19±10°, radial deviation 32±12° while patients could pronate and supinate their wrist to 85±5° and 74±20°, respectively.

CONCLUSION

Intra-articular distal radius fractures can be treated successfully with fragment specific fixation and the use of fluoroscopy. As almost all gap and step-off distances could be reduced to an acceptable level, the scope for arthroscopy to further improve this treatment regime is limited. The functional outcome scores that were found 3 months after the surgical intervention were similar to what has been reported in other studies using different treatment option. These findings suggest that fragment specific fixation is a good alternative for treating intra-articular distal radius fractures. As in most cases, only fluoroscopy is needed for fragment specific fixation, this treatment technique is a good treatment option for resource-limited hospitals, setting who do not have access to arthroscopy.

LEVEL OF EVIDENCE

III, case-control study.

A Systematic Review of the Effects of Single-Event Multilevel Surgery on Gait Parameters in Children with Spastic Cerebral Palsy

BACKGROUND

Three-dimensional gait analysis (3DGA) is commonly used to assess the effect of orthopedic single-event multilevel surgery (SEMLS) in children with spastic cerebral palsy (CP).

PURPOSE

The purpose of this systematic review is to provide an overview of different orthopedic SEMLS interventions and their effects on 3DGA parameters in children with spastic CP.

METHODS

A comprehensive literature search within six databases revealed 648 records, from which 89 articles were selected for the full-text review and 24 articles (50 studies) included for systematic review. The Oxford Centre for Evidence-Based Medicine Scale and the Methodological Index for Non-Randomized Studies (MINORS) were used to appraise and determine the quality of the studies.

RESULTS

Except for one level II study, all studies were graded as level III according to the Oxford Centre for Evidence-Based Medicine Scale. The MINORS score for comparative studies (n = 6) was on average 15.7/24, while non-comparative studies (n = 18) scored on average 9.8/16. Nineteen kinematic and temporal-distance gait parameters were selected, and a majority of studies reported improvements after SEMLS interventions. The largest improvements were seen in knee range of motion, knee flexion at initial contact and minimal knee flexion in stance phase, ankle dorsiflexion at initial contact, maximum dorsiflexion in stance and in swing phase, hip rotation and foot progression angles. However, changes in 3DGA parameters varied based on the focus of the SEMLS intervention.

DISCUSSION

The current article provides a novel overview of a variety of SEMLS interventions within different SEMLS focus areas and the post-operative changes in 3DGA parameters. This overview will assist clinicians and researchers as a potential theoretical framework to further improve SEMLS techniques within different SEMLS focus groups. In addition, it can also be used as a tool to enhance communication with parents, although the results of the studies can't be generalised and a holistic approach is needed when considering SEMLS in a child with spastic CP.

Faster Heart Rate Recovery With Increased RPE: Paradoxical Responses After an 87-km Ultramarathon

The aim of this study was to determine the relationship between heart rate recovery (HRR) and an acute training "overload" by comparing HRR responses before and after an ultramarathon road race. Ten runners completed a standardized laboratory protocol ∼7 days before and between 2 and 4 days after participating in the 87-km Comrades Marathon. The protocol included muscle pain ratings, a 5-bound test, and 20 minutes of treadmill exercise at 70% of maximal oxygen uptake followed by 15 minutes of recovery. Respiratory gases and heart rate measurements were used to calculate steady-state exercise responses, HRR, and excess postexercise oxygen consumption (EPOC), and participants also provided a rating of perceived exertion (RPE) during exercise. The RPE was significantly increased (13 ± 2 vs. 11 ± 1) (p < 0.01), and HRR was significantly faster (35 ± 5 beats vs. 29 ± 4 beats) (p < 0.01) following the postrace vs. prerace submaximal exercise bout, with no significant changes in respiratory or heart rate parameters during exercise or in EPOC. Although previous studies have shown that faster HRR reflected an "adapted" state with enhanced training status, the current findings suggest that this may not always be the case. It follows that changes in HRR should be considered in the context of other factors, such as recent training load and RPE during submaximal exercise.

A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance

The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing time-trial performance in competitive rowers. In addition, the reliability of the SmRT was investigated. Twenty-four competitive male rowers participated in this study. After determining individual HRmax, all rowers performed an SmRT followed by a 2,000-m rowing ergometer time trial. In addition, the SmRT was performed 4 times (2 days in between) to determine the reliability. The SmRT consists of two 6-minute stages of rowing at 70 and 80% HRmax, followed by a 3-minute stage at 90% HRmax. Power was captured during the 3 stages, and 60 seconds of heart rate recovery (HRR60s) was measured directly after the third stage. Results showed that predictive value of power during the SmRT on 2,000-m rowing time also increased with stages. CVTEE% is 2.4, 1.9, and 1.3%. Pearson correlations (95% confidence interval [95% CI]) were -0.73 (-0.88 to -0.45), -0.80 (-0.94 to -0.67), and -0.93 (-0.97 to -0.84). 2,000-m rowing time and HRR60s showed no relationship. Reliability of power during the SmRT improved with the increasing intensity of the stages. The coefficient of variation (CVTEM%) was 9.2, 5.6, and 0.4%. Intraclass correlation coefficients (ICC) and 95% CI were 0.91 (0.78-0.97), 0.92 (0.81-0.97), and 0.99 (0.97-1.00). The CVTEM% and ICC of HRR60s were 8.1% and 0.93 (0.82-0.98). In conclusion, the data of this study shows that the SmRT is a reliable test that it is able to accurately predict 2,000-m rowing time on an ergometer. The SmRT is a practical and valuable submaximal test for rowers, which can potentially assist with monitoring, fine-tuning and optimizing training prescription in rowers.

A Novel Intramedullary Locked Fixation Device for Treatment of Clavicle Shaft Fractures

Introduction

An intramedullary nail (the Sonoma CRx) with a unique flexible anatomical design and locking system is a viable alternative for treatment of displaced and shortened clavicle shaft fractures.

Indications & Contraindications

Step 1 Positioning

Place the patient in the beach-chair position and drape the arm free so that you can obtain an exaggerated anteroposterior and an axial fluoroscopic view of the clavicle by manipulating the position of the arm.

Step 2 Skin Incision

The surgical technique necessitates opening the fracture site in order to implant the device.

Step 3 Preparing the Medial Fragment

The preparation of the medial fragment is of utmost importance as the intramedullary Sonoma CRx nail should be placed as far as possible into the medial fragment of the clavicle, to provide the highest level of stability and the lowest risk of device failure.

Step 4 Preparing the Lateral Fragment

Preparation of the lateral fragment is more challenging than preparation of the medial fragment because of its relative immobility and shorter medullary canal.

Step 5 Placement of the Intramedullary Nail

Use the longest possible intramedullary nail that the clavicle can accommodate and insert the nail as far medially as possible into the medullary canal of the clavicle bone.

Step 6 Activation of the Locking Device

Lock the device at its medial end with distally deployed grippers and laterally with a locking screw placed through a jig.

Step 7 Management of Comminuted Fracture Fragments

Comminuted fractures are not a contraindication to the use of the intramedullary device as they can be reduced by the nail and secured by using cerclage sutures.

Step 8 Postoperative Management

Protect the affected shoulder in a shoulder immobilizer for six weeks.

Results

In our original study, forty-seven consecutive patients with a displaced and shortened clavicle shaft fracture were treated with open reduction and internal fixation using the Sonoma CRx device.

Pitfalls & Challenges

Ad-libitum drinking and performance during a 40-km cycling time trial in the heat

The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and two 40-km cycling TTs hypohydrated. During one hypohydrated trial no fluid was ingested (HYPO), during the other trial ad-libitum water ingestion was allowed (FLUID). Ambient temperature was 35.2 ± 0.2 °C, relative humidity 51 ± 3% and airflow 7 m·s(-1). Body mass (BM) was determined at the start of the test, and before and after the TT. During the TT, power output, heart rate (HR), gastrointestinal temperature, mean skin temperature, rating of perceived exertion (RPE), thermal sensation, thermal comfort and thirst sensation were measured. Prior to the start of the TT, BM was 1.2% lower in HYPO and FLUID compared to EU. During the TT, BM loss in FLUID was lower compared to EU and HYPO (1.0 ± 0.8%, 2.7 ± 0.2% and 2.6 ± 0.3%, respectively). Hydration status had no effect on power output (EU: 223 ± 32 W, HYPO: 217 ± 39 W, FLUID: 224 ± 35 W), HR, gastrointestinal temperature, mean skin temperature, RPE, thermal sensation and thermal comfort. Thirst sensation was higher in HYPO than in EU and FLUID. It was concluded that hypohydration did not adversely affect performance during a 40-km cycling TT in the heat. Therefore, whether or not participants consumed fluid during exercise did not influence their TT performance.

The treatment of clavicular shaft fractures with an innovative locked intramedullary device

BACKGROUND

Displaced and shortened clavicular shaft fractures can be treated by intramedullary fixation; however, hardware migration and soft tissue irritation at the insertion site have complicated its use. The aim of this study was to determine whether the new Sonoma CRx intramedullary device (Sonoma Orthopedic Products Inc, Santa Rosa, CA, USA) could be used successfully to treat displaced and shortened clavicular shaft fractures and restore the functional capacity of shoulder without the development of secondary complications.

METHODS

Displaced and shortened clavicular shaft fractures in 47 consecutive patients were treated with the CRx device. Incision size was captured during the surgical procedure. The union rate was evaluated postoperatively. Shoulder function was assessed by Disabilities of the Arm, Shoulder and Hand (DASH) score, the Constant Shoulder Score, and a range of motion score. Patients were assessed after 3 to 6 months (group I), 6 to 9 months (group II), or 9 to 12 months (group III) postoperatively.

RESULTS

Union was achieved in all patients at the time of review, without any incidence of hardware migration. Postoperative complications developed in 3 patients, comprising infection in 1 and hardware failure in 2. No differences among the groups were found for the DASH score (P = .33), Constant Shoulder Score (P = .38), and range of motion score (P = .96). The DASH, Constant Shoulder, and range of motion scores were similar to other successful treatment options, such as plating.

CONCLUSION

The Sonoma CRx is a good alternative device to treat displaced and shortened clavicular shaft fractures and restore the functional capacity of the shoulder. Future research should focus on when nailing and plating should be used to treat clavicular shaft fractures most optimally.

Effect of exercise intensity on post-exercise oxygen consumption and heart rate recovery

PURPOSE

There is some evidence that measures of acute post-exercise recovery are sensitive to the homeostatic stress of the preceding exercise and these measurements warrant further investigation as possible markers of training load. The current study investigated which of four different measures of metabolic and autonomic recovery was most sensitive to changes in exercise intensity.

METHODS

Thirty-eight moderately trained runners completed 20-min bouts of treadmill exercise at 60, 70 and 80% of maximal oxygen uptake (VO2max) and four different recovery measurements were determined: the magnitude of excess post-exercise oxygen consumption (EPOCMAG), the time constant of the oxygen consumption recovery curve (EPOCτ), heart rate recovery within 1 min (HRR60s) and the time constant of the heart rate recovery curve (HRRτ) .

RESULTS

Despite significant differences in exercise parameters at each exercise intensity, only EPOCMAG showed significantly slower recovery with each increase in exercise intensity at the group level and in the majority of individuals. EPOCτ was significantly slower at 70 and 80% of VO₂max vs. 60% VO₂max and HRRτ was only significantly slower when comparing the 80 vs. 60% VO₂max exercise bouts. In contrast, HRR60s reflected faster recovery at 70 and 80% of VO₂max than at 60% VO₂max.

CONCLUSION

Of the four recovery measurements investigated, EPOCMAG was the most sensitive to changes in exercise intensity and shows potential to reflect changes in the homeostatic stress of exercise at the group and individual level. Determining EPOCMAG may help to interpret the homeostatic stress of laboratory-based research trials or training sessions.

Allometric scaling and predicting cycling performance in (well-) trained female cyclists

As female cycling attains greater professionalism, a larger emphasis is placed on the ability to predict and monitor changes in their cycling performance. The main aim of this study was to determine if peak power output (PPO) adjusted for body mass (W · kg-0.32) accurately predicts flat 40-km time trial performance (40 km TT) in female cyclists as found in men. 20 (well-) trained female cyclists completed a PPO test including maximal oxygen consumption (VO2max) and a flat 40 km TT test. Relationships between cycling performance parameters were also compared to the cycling performance of 45 male cyclists. Allometrically scaled PPW (W · kg(-0.32)) most accurately predicted 40 km TT performance in the female cyclists (r = -0.87, p<0.0001) compared to any other method, however different slopes between the parameters were found in the female and male cyclists (p=0.000115). In addition gender differences were also found between the relationship between relative PPO (W · kg-1) and relative VO2max (ml · min-1 · kg(-1))(p<0.0001), while no gender differences were found between actual and predicted cycling performance based on the Lamberts and Lambert Submaximal Cycle Test (LSCT), which was used a standardized warm-up. In conclusion, relationships between relative cycling parameters seem to differ between genders, while relationships between absolute cycling parameters seem to be similar. Therefore gender specific regression equations should be used when predicting relative cycling performance parameters.

A novel submaximal cycle test to monitor fatigue and predict cycling performance

OBJECTIVE

The purpose of this study was to determine the reliability and predictive value of performance parameters, measured by a new novel submaximal cycle protocol, on peak power and endurance cycling performance in well-trained cyclists.

METHODS

Seventeen well-trained competitive male road racing cyclists completed four peak power output (PPO) tests and four 40-km time trials (40-km TT). Before each test, all cyclists performed a novel submaximal cycle test (Lamberts and Lambert Submaximal Cycle Test (LSCT)). Parameters associated with performance such as power, speed, cadence and rating of perceived exertion (RPE) were measured during the three stages of the test when cyclists rode at workloads coinciding with fixed predetermined heart rates. Heart rate recovery (HRR) was measured after the last stage of the test.

RESULTS

Parameters measured during the second and third stages of the LSCT were highly reliable (intraclass correlation range: R=0.85-1.00) with low typical error of measurements (range: 1.3-4.4%). Good relationships were found between the LSCT and cycling performance measured by the PPO and 40-km TT tests. Mean power had stronger relationships with measures of cycling performance during the second (r=0.80-0.89) and third stages (r=0.91-0.94) of the LSCT than HRR (r=0.55-0.68).

CONCLUSIONS

The LSCT is a reliable novel test which is able to predict peak and endurance cycling performance from submaximal power, RPE and HRR in well-trained cyclists. As these parameters are able to detect meaningful changes more accurately than VO(2max), the LSCT has the potential to monitor cycling performance with more precision than other current existing submaximal cycle protocols.

Effects of high-intensity training by heart rate or power in well-trained cyclists

The aim of this study was to determine whether the performance of cyclists after 4 weeks of high-intensity training improved similarly using either heart rate or power to prescribe training. Twenty-one well-trained men cyclists (age, 32 +/- 6 years; peak power output, 371 +/- 46 W) were randomly assigned to a power-based (GPOWER) or heart rate-based (GHEART) high-intensity training (HIT) group or a control group (GCONTROL). Training consisted of 8 repetitions of 4 minutes at either 80% of peak power output (GPOWER) or at the heart rate coinciding with 80% of peak power output (GHEART), with rest periods of 90 seconds. A 40-km time trial and VO2max test were performed before and after 8 training sessions. There were significant improvements (p < 0.05) in peak power output (GPOWER = 3.5%; GHEART = 5.0%) and 40-km time trial performance (GPOWER = 2.3%; GHEART = 2.1%) for both of the high-intensity groups. Although there were no significant differences between groups for these variables, when the data were analyzed using magnitude-based effects, the GHEART group showed greater probability of a "beneficial" effect for peak power output. The current general perception that prescribing training based only on power is more effective than prescribing training based on heart rate was not supported by the data from this study. Coaches who are unable to monitor progress frequently should prescribe training based on heart rate, when intervals are performed under stable conditions, because this may provide an additional advantage over prescribing training using power.

Functional status of patients with cerebral palsy according to the International Classification of Functioning, Disability and Health model: a 20-year follow-up study after selective dorsal rhizotomy

OBJECTIVE

To determine functional status of patients with cerebral palsy 20 years after they received selective dorsal rhizotomy (SDR).

DESIGN

A prospective 20-year follow-up study.

SETTING

Red Cross Children's Hospital (SDR operation and 1-year follow-up assessment) and at institutional or private locations nearby patients' homes (20-year follow-up assessment).

PARTICIPANTS

Referred sample of 14 patients with spastic diplegia (6 women, 8 men; mean age, 27y; range, 22-33y) who were preoperatively ambulant and fulfilled strict selection criteria for SDR operation in 1985.

INTERVENTIONS

Patients were assessed before and 1 and 20 years after SDR.

MAIN OUTCOME MEASURES

Standardized assessments of function according to 2 dimensions of the International Classification of Functioning, Disability and Health (ICF) model: (1) body structure and function (muscle tone, joint stiffness, voluntary movement) and (2) activity (rolling, sitting, kneeling, crawling, standing, walking, transitions) were obtained. In addition, based on assessments and questionnaires, Gross Motor Function Classification System (GMFCS) levels were determined before and at 1 year after SDR retrospectively and currently at 20 years after SDR.

RESULTS

One year after SDR, functional outcomes based on the 2 dimensions of the ICF model improved significantly, and these improvements were maintained at 20 years after surgery. Patients showed a shift in their GMFCS levels 1 and 20 years after SDR.

CONCLUSIONS

In line with our 20-year follow-up study with gait parameters as outcome measures, patients with spastic diplegia still show improvements in their functional status 20 years after SDR. We acknowledge the presence of possible confounding factors and a small sample size, but we argue that the improvements found in this study were caused mainly by SDR. Finally, changes in GMFCS levels suggest a possible role for this tool to detect changes after an intervention.