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.