Characterizing Longitudinal Alterations in Postural Control Following Lower Limb Injury in Professional Rugby Union Players.

Assessment of player's postural control following a lower limb injury is of interest to sports medicine practitioners due to its fundamental role in daily tasks and sporting activities. The aim was to longitudinally monitor professional rugby union players' postural control during each phase of the rehabilitation program (acute, middle, and late) following a lower limb injury. Seven male rugby union players (height 1.80 [0.02] m; mass 100.3 [11.4] kg; age 24 [4] y) sustained a time loss, noncontact lower limb injury. Static postural control was assessed via sway path (in meters), and dynamic postural control was assessed via vertical postural stability index. Group differences (P < .05) were reported across the acute, middle, and late phase. Smaller magnitudes of sway path were observed for eyes-open sway path, and for the middle and late phase smaller magnitudes of vertical postural stability index (P < .05) at the end session compared with first session. Whereas larger magnitudes of vertical postural stability index were found between baseline and the last session (P < .05). Large interindividual and intraindividual variation was apparent across the 3 phases of rehabilitation. Postural control improvements were identified during rehabilitation. However, postural control did not return to baseline, with altered kinetics throughout each rehabilitation phase.

Muscle damaging eccentric exercise attenuates disuse-induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men.

Short-term disuse leads to muscle loss driven by lowered daily myofibrillar protein synthesis (MyoPS). However, disuse commonly results from muscle damage, and its influence on muscle deconditioning during disuse is unknown. Twenty-one males [20 ± 1 yr, BMI = 24 ± 1 kg·m-2 (± SE)] underwent 7 days of unilateral leg immobilization immediately preceded by 300 bilateral, maximal, muscle-damaging eccentric quadriceps contractions (DAM; subjects n = 10) or no exercise (CON; subjects n = 11). Participants ingested deuterated water and underwent temporal bilateral thigh MRI scans and vastus lateralis muscle biopsies of immobilized (IMM) and nonimmobilized (N-IMM) legs. N-IMM quadriceps muscle volume remained unchanged throughout both groups. IMM quadriceps muscle volume declined after 2 days by 1.7 ± 0.5% in CON (P = 0.031; and by 1.3 ± 0.6% when corrected to N-IMM; P = 0.06) but did not change in DAM, and declined equivalently in CON [by 6.4 ± 1.1% (5.0 ± 1.6% when corrected to N-IMM)] and DAM [by 2.6 ± 1.8% (4.0 ± 1.9% when corrected to N-IMM)] after 7 days. Immobilization began to decrease MyoPS compared with N-IMM in both groups after 2 days (P = 0.109), albeit with higher MyoPS rates in DAM compared with CON (P = 0.035). Frank suppression of MyoPS was observed between days 2 and 7 in CON (IMM = 1.04 ± 0.12, N-IMM = 1.86 ± 0.10%·day-1; P = 0.002) but not DAM (IMM = 1.49 ± 0.29, N-IMM = 1.90 ± 0.30%·day-1; P > 0.05). Declines in MyoPS and quadriceps volume after 7 days correlated positively in CON (r2 = 0.403; P = 0.035) but negatively in DAM (r2 = 0.483; P = 0.037). Quadriceps strength declined following immobilization in both groups, but to a greater extent in DAM. Prior muscle-damaging eccentric exercise increases MyoPS and prevents loss of quadriceps muscle volume after 2 (but not 7) days of disuse.NEW & NOTEWORTHY We investigated the impact of prior muscle-damaging eccentric exercise on disuse-induced muscle deconditioning. Two and 7 days of muscle disuse per se lowered quadriceps muscle volume in association with lowered daily myofibrillar protein synthesis (MyoPS). Prior eccentric exercise prevented the decline in muscle volume after 2 days and attenuated the decline in MyoPS after 2 and 7 days. These data indicate eccentric exercise increases MyoPS and transiently prevents quadriceps muscle atrophy during muscle disuse.

Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population.

BACKGROUND: Lower extremity fractures represent a high percentage of reported injuries in the United States military and can devastate a service member's career. A passive dynamic ankle-foot orthosis (PD-AFO) with a specialized rehabilitation program was initially designed to treat military service members after complex battlefield lower extremity injuries, returning a select group of motivated individuals back to running. For high-demand users of the PD-AFO, the spatiotemporal gait parameters, agility, and quality of life is not fully understood with respect to uninjured runners. QUESTIONS/PURPOSES: Do patients who sustained a lower extremity fracture using a PD-AFO with a specialized rehabilitation program differ from uninjured service members acting as controls, as measured by (1) time-distance and biomechanical parameters associated with running, (2) agility testing (using the Comprehensive High-level Activity Mobility Predictor performance test and Four Square Step Test), and (3) the Short Musculoskeletal Function Assessment score. METHODS: We conducted a retrospective data analysis of a longitudinally collected data registry of patients using a PD-AFO from 2015 to 2017 at a single institution. The specific study cohort were patients with a unilateral lower extremity fracture who used the PD-AFO for running. Patients had to be fit with a PD-AFO, have completed rehabilitation, and have undergone a three-dimensional (3-D) running analysis at a self-selected speed at the completion of the program. Of the 90 patients who used the PD-AFO for various reasons, 10 male service members with lower extremity fractures who used a PD-AFO for running (median [range] age 29 years [22 to 41], height 1.8 meters [1.7 to 1.9], weight 91.6 kg [70 to 112]) were compared with 15 uninjured male runners in the military (median age 33 years [21 to 42], height 1.8 meters [1.7 to 1.9], weight 81.6 kg [71.2 to 98.9]). The uninjured runners were active-duty service members who voluntarily participated in a gait analysis at their own self-selected running speeds; to meet eligibility for inclusion as an uninjured control, the members had to be fit for full duty without any medical restrictions, and they had to be able to run 5 miles. The controls were then matched to the study group by age, weight, and height. The primary study outcome variables were the running time-distance parameters and frontal and sagittal plane kinematics of the trunk and pelvis during running. The Four Square Step Test, Comprehensive High-level Activity Mobility Predictor scores, and Short Musculoskeletal Function Assessment scores were analyzed for all groups as secondary outcomes. Nonparametric analyses were performed to determine differences between the two groups at p < 0.05. RESULTS: For the primary outcome, patients with a PD-AFO exhibited no differences compared with uninjured runners in median (range) running velocity (3.9 meters/second [3.4 to 4.2] versus 4.1 meters/second [3.1 to 4.8], median difference 0.2; p = 0.69), cadence (179 steps/minute [169 to 186] versus 173 steps/minute [159 to 191], median difference 5.8; p = 0.43), stride length (2.6 meters [2.4 to 2.9] versus 2.8 meters [2.3 to 3.3], median difference 0.2; p = 0.23), or sagittal plane parameters such as peak pelvic tilt (24° [15° to 33°] versus 22° [14° to 28°], median difference 1.6°; p = 0.43) and trunk forward flexion (16.2° [7.3° to 23°) versus 15.4° [4.2° to 21°), median difference 0.8°; p > 0.99) with the numbers available. For the secondary outcomes, runners with a PD-AFO performed worse in Comprehensive High-level Activity Mobility Predictor performance testing than uninjured runners did, with their four scores demonstrating a median (range) single-limb stance of 35 seconds (32 to 58) versus 60 seconds (60 to 60) (median difference 25 seconds; p < 0.001), t-test result of 15 seconds (13 to 20) versus 13 seconds (10 to 14) (median difference 2 seconds; p < 0.001), and Illinois Agility Test result of 22 seconds (20 to 25) versus 18 seconds (16 to 20) (median difference 4; p < 0.001). Edgren side step test result of 20 meters (16 to 26) versus 24 meters (16 to 29) (median difference 4 meters; p = 0.11) and the Four Square Step Test of 5.5 seconds (4.1 to 7.2) versus 4.2 seconds (3.1 to 7.3) (median difference 1.3 seconds; p = 0.39) were not different between the groups with an effect size of 0.83 and 0.75, respectively. CONCLUSION: The results of our study demonstrate that service members run with discernible differences in high-level mobility and demonstrate inferior self-reported patient functioning while having no differences in speed and biomechanics compared with their noninjured counterparts with the sample size available. This study is an early report on functional gains of highly motivated service members with major lower extremity injuries who use a PD-AFO and formalized therapy program to run. LEVEL OF EVIDENCE: Level III, therapeutic study.

Symmetry does not Indicate Recovery: Single-leg Hop Before and After a Lower Extremity Injury.

Current recommendations for return-to-play decision-making involve comparison of the injured limb to the uninjured limb. However, the use of the uninjured limb as a comparison for hop testing lacks empirical evidence. Thus, the purpose of this study was to determine the effects of lower extremity injury on limb symmetry and performance on the single-leg hop for distance. Two-hundred thirty-six adolescent athletes completed the single-leg hop for distance before the beginning of the season (pre-injury). Forty-four adolescent athletes sustained a lower extremity injury (22 ankle and 12 knee) and missed at least three days of sports participation. All individuals had completed the single-leg hop for distance before the beginning of the season (pre-injury) and at discharge (post-injury). Injured limb single-leg hop for distance significantly decreased at return-to-play from pre-injury with a mean decrease of 48.9 centimeters; the uninjured limb also significantly decreased, with a mean decrease of 33.8 centimeters. Limb symmetry did not significantly change pre- to post-injury with a mean difference of 1.5%. Following a lower extremity injury, single-leg hop for distance performance degrades not only for the injured limb but also the uninjured limb. However, limb symmetry did not change following a lower extremity injury.

Biomechanical analysis of two runners who developed leg injuries during a six-week transition to maximal running shoes: A case series.

Achilles tendinopathy (AT) and medial tibial stress syndrome (MTSS) are two of the most common running-related injuries. In a previous study investigating running biomechanics before and after a six-week transition to maximal running shoes, two runners dropped out of this study due to Achilles pain and shin pain, respectively. The purpose of this case series was to investigate running biomechanics in those two runners, identifying potential causes for injury in relation to maximal shoe use. Running biomechanics were collected in a laboratory setting for these two runners wearing both a maximal running shoe and traditional running shoe before the six-week transition using an 8-camera motion capture system and two embedded force plates. Both runners displayed prolonged eversion in the maximal shoe, which has been previously cited as a potential risk factor for developing Achilles tendinopathy and medial tibial stress syndrome. Relatively high loading rates and impact forces were also observed in the runner with shin pain in the maximal shoe, which may have contributed to their pain. More prospective research on injury rates in individuals running in maximal shoes is needed.

The Influence of Injury History on Countermovement Jump Performance and Movement Strategy in Professional Soccer Players: Implications for Profiling and Rehabilitation Foci.

CONTEXT: Professional soccer players who have sustained a lower limb injury are up to 3× more likely to suffer a reinjury, often of increased severity. Previous injury has been shown to induce compensatory strategies during neuromuscular screening tests, which might mask deficits and lead to misinterpretation of readiness to play based on task outcome measures. OBJECTIVE: To investigate the influence of previous injury in professional soccer players on countermovement jump (CMJ) performance and movement strategy. DESIGN: Cross-sectional. SETTING: Professional soccer club competing in the English Championship (tier 2). Patients (or Other Participants): Outfield players with a minimum of 6 years as a professional. INTERVENTION(S): Players were categorized as previously injured (n = 10) or not injured (n = 10). All players completed double- and single-leg CMJ trials. MAIN OUTCOME MEASURES: CMJ performance was quantified as jump height and flight time:contraction time ratio. CMJ movement strategy was quantified as force-time history, differentiating eccentric and concentric phases and CMJ depth. RESULTS: Double-leg CMJ was not sensitive to previous injury in performance or movement strategy. In contrast, single-leg CMJ performance was impaired in players with previous injury, who generated significantly lower eccentric and concentric peak force and rate of force development, and a deeper countermovement. Impaired single-leg CMJ performance was also evident in the nonaffected limb of previously injured players, suggesting cross-contamination. Hierarchical ordering revealed that the eccentric phase of the CMJ contributed little to performance in previously injured players. In noninjured players, the eccentric rate of force development and concentric peak force were able to account for up to 89% of the variation in CMJ performance. CONCLUSIONS: Single-leg CMJ is advocated for player profiling, being more sensitive to previous injury, and negating the opportunity for interlimb compensation strategies. Movement strategy deficits in previously injured players suggest rehabilitation foci specific to eccentric force development.

Correlating clinical assessment and MRI findings in diagnosing calf injuries in elite male Australian rules footballers.

OBJECTIVE: Calf complex injuries represent a significant injury burden among Australian Rules athletes. To date, there has been limited research correlating clinical and radiological findings of pathology within the calf. The objective of this study is to determine how accurately magnetic resonance imaging (MRI) findings correlate with clinical measures of calf muscle complex pathology in elite male athletes. MATERIALS AND METHODS: A prospective cohort study was conducted on Australian rules elite athletes. A cohort of 45 athletes underwent a high-load training session of approximately 10 km of running. Athletes were then assessed by a sports physiotherapist who made a diagnosis of no pathology, delayed onset muscle soreness, strain or other. Subsequently, the athletes underwent MRI of their bilateral calf complexes. Radiologists interpreted the MRI findings and radiological diagnosis were correlated with clinical diagnosis. RESULTS: A total of 90 calf MRIs were performed. Correlation of clinical and radiological diagnosis occurred in 57 cases. Of the 33 cases which did not correlate, there were 4 radiologically significant acute calf strains in clinically asymptomatic athletes, 3 of which involved old scar tissue. CONCLUSION: MRI may detect clinically insignificant injuries within the calf complex. If an athlete does not have any clinically relevant symptoms, abnormal signal on MRI may represent a different diagnosis to muscle strain. Signal change on MRI proximal to scar tissue may represent reactive oedema. Clinical history and examination should be correlated with radiological findings is recommended when diagnosing calf injury in elite athletes.

Excellent clinical outcome and low complication rate after proximal hamstring tendon repair at mid-term follow up.

PURPOSE: Proximal hamstring tendon avulsions lead to a significant loss of strength and a functional deficit of the respective lower limb and surgery is the recommended treatment. Only little is known about the clinical outcomes and complications when comparing acute and chronic management as well as partial and complete tears. Therefore, the purpose of this study was to investigate the clinical results and the complication rate of patients after surgical treatment of proximal hamstring tendon injuries. It was hypothesized that surgical treatment of an acute proximal hamstring avulsion would lead to a superior clinical outcome with a low complication rate and high return to sports rate compared to chronic cases and partial avulsions. METHODS: Patients who underwent proximal hamstring tendon repair between 2008 and 2015 were retrospectively evaluated with a minimum follow up of 2 years. Outcome measurements were obtained by means of Lysholm score, Harris Hip Score, Visual Analog Scale, and Tegner Activity Scale. Return to sports (RTS) rate was determined. Postoperative adverse events were recorded and complications reported. Patients' outcomes were compared between acute/chronic repair and partial/complete injury patterns. RESULTS: Ninety-four of 120 (78.3%) were available for final assessment at a mean follow-up of 56.2 ± 27.2 months. Clinical outcome measures were excellent and did not differ between the treatment groups or between the different injury patterns. RTS was achieved by 86.2% of the patients and was significantly superior after acute treatment (p < 0.05). The overall complication rate was 8.5% and significantly higher in complete tears compared to partial tears and in delay compared to acute surgery (p < 0.05). CONCLUSION: Surgical treatment of proximal hamstring tendon avulsions results in excellent clinical outcome scores and a high RTS rate. Open surgical treatment has shown to be a safe procedure with a low complication rate. Surgical timing is important, as early surgical intervention provides a higher RTS rate and a lower complication rate than delayed surgery and should therefore be preferred in clinical practice. Repair of partial and complete tears lead to similar clinical outcome, but a higher complication rate in complete avulsions. LEVEL OF EVIDENCE: Level IV.

Thromboprophylaxis in lower limb immobilisation after injury (TiLLI).

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures and result in significant loss of disability adjusted life years. Temporary lower limb immobilisation after injury is a significant contributor to the overall burden of venous thromboembolism (VTE). Existing evidence suggests that pharmacological prophylaxis could reduce overall VTE event rates in these patients, but the proportional reduction of symptomatic events remains unclear. Recent studies have used different pharmacological agents, dosing regimens and outcome measures. Consequently, there is wide variation in thromboprophylaxis strategies, and international guidelines continue to offer conflicting advice for clinicians. In this review, we provide a summary of recent evidence assessing both the clinical and cost effectiveness of thromboprophylaxis in patients with temporary immobilisation after injury. We also examine the evidence supporting stratified thromboprophylaxis and the validity of widely used risk assessment methods.

A case-control pilot study of stress fracture in adolescent girls: the discriminative ability of two imaging technologies to classify at-risk athletes.

Since stress fractures are common among adolescent athletes, it is important to identify bone assessment tools that accurately identify risk. We investigated the discriminative ability of two imaging technologies to classify at-risk athletes. Findings suggested that peripheral quantitative computed tomography (pQCT) has the ability to distinguish differences in bone structure in injured vs. uninjured limbs. INTRODUCTION: Given the high stress fracture (SFX) prevalence among adolescent girls, an understanding of the most informative assessment tools to identify SFX risks are required. We investigated the discriminative ability of pQCT vs. dual-energy X-ray absorptiometry (DXA) to classify athletes with or without SFX. METHODS: Twelve adolescent athletes diagnosed with a lower-extremity SFX were compared with 12 matched controls. DXA measured areal bone mineral density (aBMD) and content of the total body, and lumbar spine. Bilateral tibiae were assessed with pQCT. At the metaphysis (3%), total density (ToD), trabecular density (TrD), trabecular area (TrA), and estimated bone strength in compression (BSIc), and at the diaphysis (38% and 66%), total bone area (ToA), cortical density (CoD), cortical area (CoA), estimated bone strength in torsion (SSIp), and peri- and endocortical and muscle area (MuA) were obtained. Cortical bone mass/density around the center of mass and marrow density (estimate of adiposity) were calculated using ImageJ software. General estimated equations adjusting for multiple comparisons (Holm-Bonferroni method) were used to compare means between (1) injured limb of the case athletes vs. uninjured limb of the control athletes and (2) uninjured limb of the case athletes vs. uninjured limbs of the controls and injured vs. uninjured limb of case athletes with a SFX. RESULTS: aBMD and content showed no significant differences between cases and controls. When comparing the injured vs. uninjured leg in the case athletes by pQCT at the 3% tibia, unadjusted TrD, total density, and BSIc were significantly lower (p < 0.05) in the injured vs. uninjured leg. Marrow density at the 66% site was 1% (p < 0.05) lower in the injured vs. uninjured leg. CONCLUSIONS: These preliminary data in athletes with SFX suggest that pQCT has the ability to distinguish differences in bone structure in injured vs. uninjured limbs. No discriminative bone parameter classifications were identified between adolescent athletes with or without SFX.

Catheter-Based Computed Tomography Angiography in Anterolateral Thigh Perforator Mapping of Chinese Patients.

BACKGROUND: During reconstructive surgery, anterolateral thigh (ALT) flap harvest is challenging due to variation and uncertainty in perforator distribution. We performed a pilot study to identify the predictive value of catheter-based computed tomography angiography (C-CTA) and traditional CTA (T-CTA) in ALT perforator mapping for patients whose ALT perforators were difficult to identify. METHODS: Thirty-four consecutive T-CTA/C-CTA-mapped ALT flaps were evaluated for extremity reconstruction. The perforator location, origin, and course were compared between T-CTA/C-CTA imaging and intraoperative findings. The mapping efficiency of T-CTA and C-CTA was compared thoroughly. RESULTS: Among the 34 ALT thigh flaps, 117 (36) of the 130 perforators identified intraoperatively were visible on C-CTA (T-CTA) in a subgroup of Chinese limb trauma patients with limited activity. C-CTA showed a satisfactory efficiency in perforator mapping, which was much better than the efficiency of T-CTA. C-CTA also showed a much better sensitivity (90.00 vs. 27.69%), specificity (94.74 vs. 66.67%), and accuracy (91.07 vs. 36.69%), and a much lower false-positive (1.68 vs. 26.53%), and false-negative rate (10.00 vs. 72.31%). Moreover, C-CTA could accurately predict the origin and septocutaneous or intramuscular course in all identified perforators. All flaps were elevated successfully and survived. CONCLUSION: C-CTA outperforms T-CTA in the preoperative perforator mapping of ALT flaps in a subgroup of Chinese limb trauma patients. C-CTA should be the method of choice for perforator mapping in patients whose ALT flaps are intended for extremity reconstruction.

Obesity and Lower Extremity Reconstruction: Evaluating Body Mass Index as an Independent Risk Factor for Early Complications.

BACKGROUND: The prevalence of obesity in the United States continues to grow and is estimated to affect over a quarter of the working-age population. Some studies have identified obesity as a risk factor for flap failure and complications in free flap-based breast reconstruction, but its clinical significance is less clear in nonbreast reconstruction. The role of obesity as a risk factor for failure and complications following lower extremity reconstruction has not been well described, and the limited existing literature demonstrates conflicting results. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was reviewed to identify patients undergoing local- or free-flap reconstruction of the lower extremity between 2010 and 2015. Preoperative variables and outcomes were compared between obese (body mass index ≥ 30) and nonobese patients. Chi-square analysis and Fisher's exact test were used for categorical variables and t-tests for continuous variables. Multivariate regression was performed to control for confounders. RESULTS: Univariate analysis of medical and surgical outcomes revealed that obese patients undergoing local flaps of the lower extremity required a significantly longer operative time (187.7 ± 123.2 vs. 166.2 ± 111.7 minutes; p = 0.003) and had significantly higher rates of superficial surgical site infection (SSI; 7.2% vs. 4.5%; p = 0.04). On univariate analysis, there were no significant differences in any postoperative outcomes between obese and nonobese patients undergoing microvascular free flaps of the lower extremity.On multivariate regression analysis, obesity was not an independent risk factor for superficial SSI (odds ratio = 1.01, p = 0.98) or increased operative time (ß = 16.01, p = 0.14) for local flaps of the lower extremity. CONCLUSION: Evaluation of a large, multicenter, validated and risk-adjusted nationwide cohort demonstrated that obesity is not an independent risk factor for early complications following lower extremity reconstruction, suggesting that these procedures may be performed safely in the obese patient population.

Is Early Compression Therapy after Perforator Flap Safe and Reliable?

BACKGROUND: Due to the concern of circulation compromise, many surgeons hesitate to dangle or challenge the flap in the early postoperative phase. In our experience, early compression may have advantages such as collapse of dead space, evacuation of hematoma, reduction of edema, and stabilization of flap when ambulating. In this study, the effect of early compression of flaps with regard to flap physiology and outcome is evaluated. METHODS: From postoperative day 3 to 5, a custom-made compression garment was fitted aiming to compress with a pressure of 30 to 35 mmHg. A total of 52 patients (52 flaps) were enrolled for the study and 48 flaps underwent early compression. The compression was applied not only over the flap but also over the extremity or trunk. The flap outcome as well as flow velocity and flow volume of the pedicle before and after compression was measured and evaluated. RESULTS: There was no flap complication during the early compression and early ambulation. And, there was no statistical difference either in the flow velocity or in the volume before and after the compression therapy (29.21 vs. 29.42 cm/s and 7.13 vs. 6.56 cm3/s, respectively). CONCLUSION: Early compression with a 30-mmHg pressure customized pressure garment after the flap surgery does not affect the hemodynamics of the perforator and can be safely used after extremity reconstruction before ambulation.

Flow-Through Flaps in the Absence of an Arterial Gap for Extremity Defect Reconstruction: Minimizing the Donor-Site Morbidity.

BACKGROUND: The use of flow-through flaps was popularized in the early 1990s by Costa, Soutar and Lamberty in cases where an arterial gap was present or a major artery of the limb was damaged. We hypothesized that flow-through flaps can be used in all extremity reconstruction cases, where there is an indication for a free-flap, irrespective of the existence of arterial defect due to its many advantages while not increasing the flap loss significantly. METHODS: A retrospective study was performed by examining patient status and surgery reports of all patients who underwent extremity reconstruction with a flow-through flap from January 2011 to January 2016. This procedure was applied to all the patients, irrespective of the presence of an arterial gap. RESULTS: Forty-seven patients were included. The most frequently used flaps were the anterolateral thigh flap and the latissimus dorsi flap. Reconstructions were either posttraumatic or after oncological resection. Two cases of flap loss were encountered. The mean total operating time was 480 ± 153 minutes. The mean follow-up was 10 ± 3 months. There were no donor-site wound complications. CONCLUSION: Based on our results, the flow-through flap technique can be considered a safe alternative to the end-to-side technique for complex extremity defect reconstruction irrespective of the vascular status. The additional arterial anastomosis, even in the absence of an arterial gap or a vascular compromised extremity, did not increase the complication rate in the hands of experienced microsurgeons.

Does the amount of lower extremity movement variability differ between injured and uninjured populations? A systematic review.

Movement variability during repetitive performance of a dynamic activity (eg, running, jumping, kicking) is considered an integral characteristic of optimal movement execution; however, its relationship with musculo-skeletal injury is not known. The primary aim of this study was to review published comparison trials to determine whether movement variability differs between uninjured controls and subjects with a lower limb musculo-skeletal injury. A systematic search of online databases; MEDLINE, Sports Discus, Scopus, and Web of Science was conducted from July to November 2016. Studies were selected if they (a) included participants with a lower limb injury, (b) compared injured participants to uninjured controls, (c) examined movement variability for at least one dependent variable, and (d) provided a statistical between-group comparison when comparing measures of movement variability. Studies were excluded if they (a) investigated neurological disorders, (b) examined musculo-skeletal injury in the upper extremity or spine, and (c) used nonlinear measures to examine variability (ie, complexity). A significant difference between injured and uninjured populations was reported in 73% of the included studies, and of these, 64% reported greater movement variability in the injured group. This is the first systematic review with a best-evidence synthesis investigating the association between movement variability and musculo-skeletal injury. Findings suggest that movement variability in those with a musculo-skeletal injury differs from uninjured individuals. Interestingly, there was an overall trend toward greater movement variability being associated with the injured groups, although it should be noted that this trend was not consistent across all subcategories (eg, injury type). For a clearer insight into the clinical application of variability, greater methodological homogeneity is required and prospective research is recommended.

Kinematic chain-related risk factors in the development of lower extremity injuries in women: A prospective study.

The link between dynamic range of motion (dROM) parameters within the kinematic chain and the development of lower extremity (LE) injury has gained attention; however, very few longitudinal studies have been conducted. Therefore, we wanted to prospectively determine dROM-related risk factors for the development of LE injury. Within this study, 90 female physical education students aged 19.33±0.87 years were tested. Full-body kinematic and vertical ground reaction force (VGRF) parameters were measured during a triple hop jump (THJ). Cox regression analysis was used to identify potential risk factors for the development of LE injury. The injury follow-up was assessed using a weekly online questionnaire and a tri-monthly retrospective control questionnaire. Lower extremity injury was diagnosed by an experienced medical doctor. During the follow-up, 39 percent of the participants were diagnosed with a LE injury. Decreased dROM of the pelvic segment (P=.043) and increased dROM of the knee and ankle joint (P=.041 and P=.028, respectively) in the sagittal plane during landing phase were identified as predictive parameters for the development of LE injury in women. No VGRF parameters were identified as predictive variables. It can be concluded that an altered dROM within the LE kinematic chain was observed within the group at risk for LE injury. More specifically, this group showed reduced proximal dROM that was coupled with increased dROM in the distal segments during a THJ. The THJ can be seen as a practical screening tool for LE injury.

Step time asymmetry increases metabolic energy expenditure during running.

To improve locomotor performance, coaches and clinicians encourage individuals with unilateral physical impairments to minimize biomechanical asymmetries. Yet, it is unknown if biomechanical asymmetries per se, affect metabolic energy expenditure in individuals with or without unilateral impairments during running. Thus, inter-leg biomechanical asymmetries may or may not influence distance-running performance. PURPOSE: We sought to determine whether running with asymmetric step times affects metabolic rate in unimpaired individuals. METHODS: Ten unimpaired individuals were instructed to run on a force-measuring treadmill at 2.8 m/s and contact the ground simultaneously to the beat of an audible metronome. The metronome either played at time intervals equal to the respective participant's preferred step times (0% asymmetry), or at time intervals that elicited asymmetric step times between legs (7, 14, and 21% step time asymmetry); stride time remained constant across all trials. We measured ground reaction forces and metabolic rates during each trial. RESULTS: Every 10% increase in step time and stance average vertical ground reaction force asymmetry increased net metabolic power by 3.5%. Every 10% increase in ground contact time asymmetry increased net metabolic power by 7.8%. More asymmetric peak braking and peak propulsive ground reaction forces, leg stiffness, as well as positive and negative external mechanical work, but not peak vertical ground reaction force, increased net metabolic power during running. Step time asymmetry increases the net metabolic power of unimpaired individuals during running. Therefore, unimpaired individuals likely optimize distance-running performance by using symmetric step times and overall symmetric biomechanics.

Lower Extremity Horizontal Work But Not Vertical Power Predicts Lower Extremity Injury in Female Collegiate Dancers.

Ambegaonkar, JP, Schock, CS, Caswell, SV, Cortes, N, Hansen-Honeycutt, J, and Wyon, MA. Lower extremity horizontal work but not vertical power predicts lower extremity injury in female collegiate dancers. J Strength Cond Res 32(7): 2018-2024, 2018-Dancers often perform powerful and explosive movements that require adequate lower extremity (LE) activity in horizontal and vertical directions. We examined whether these measures were interrelated and whether they predicted LE injury status in dancers using binary logistic regressions and receiver operator characteristic (ROC) curve analyses. Forty-three collegiate female dancers (18 ± 0.7 years; 162.6 ± 5.9 cm; 59.4 ± 7.1 kg) performed single leg hop (SLH, m) and vertical jump (VJ, cm) tests. Single leg hop and VJ distances were used to calculate SLH norm (as a % of body height) and vertical power (vPower, watts). Lower extremity injuries and dance exposure hours (DEhrs) were recorded for 16 weeks. Dancers had 51 injuries resulting in a 3.7/1,000 DEhr injury incidence rate (95% confidence interval [CI]: 2.7-4.7). Twenty dancers were injured, whereas 23 remained injury free. Injured dancers had significantly lower SLH norm than noninjured dancers (t = 2.7, p = 0.009, 85.2 ± 11.2% vs. 76.8 ± 8.4%, respectively), but vPower was similar (t = 0.6, p = 0.53, injured = 2,632.0 ± 442.9 watts, noninjured = 2,722.7 ± 480.0 watts). SLH norm, but not vPower significantly predicted injury status χ(1,43) = 5.9, p = 0.02. Specifically, an SLH norm cut-off value of 78.2% identified dancers at injury risk (area under the curve = 0.73, SE = 0.08, p = 0.01, 95% CI = 0.57-0.89, sensitivity = 0.75, specificity = 0.70). However, vPower was not able to identify dancers at risk (p = 0.36). vPower had moderate relationships with SLH norm (r = 0.31, p = 0.04). Compared with injured dancers, noninjured dancers had greater SLH norm but similar vPower. Only SLH norm predicted injury status in female collegiate dancers. Thus, the SLH test may possibly predict LE injury risk in dancers. Strength and conditioning coaches can prospectively use baseline SLH test screenings to identify dancers whose SLH is less than 78.2% of their height because these dancers may have increased probability of LE injury risk. Coaches can then include horizontal direction exercises when designing training programs and examine whether these programs reduce LE injury risk in female collegiate dancers.

Meta-analysis of Timing for Microsurgical Free-Flap Reconstruction for Lower Limb Injury: Evaluation of the Godina Principles.

BACKGROUND: In 1986, Marko Godina published his seminal work regarding the timing of free-flap reconstruction for traumatic extremity defects. Early reconstruction, compared with delayed and late reconstruction resulted in significant decreases in free-flap failure rate, post-operative infections, hospitalization time, bone healing time, and number of additional anesthesias. The objective of this manuscript was to evaluate whether these principles continue to apply. METHODS: A meta-analysis was performed analyzing articles from Medline, Embase, and Pubmed. Four hundred and ninety-two articles were screened, and 134 articles were assessed for eligibility. Following full-text review, 43 articles were included in this study. RESULTS: The exact timing for free-flap reconstruction, free-flap failure rate, infection rate, and follow-up was defined in all 43 articles. Early free-flap reconstruction was found to have significantly lower rates of free-flap failure and infection in comparison to delayed reconstruction (p = 0.008; p = 0.0004). Compared with late reconstruction, early reconstruction was found to have significantly lower infection rates only (p = 0.01) with no difference in free-flap failures rates. Early reconstruction was found to lead to fewer additional procedures (p = 0.03). No statistical significance was found for bone healing time or hospitalization time. CONCLUSION: Early free-flap reconstruction performed within the first 72 hours resulted in a decreased rate of free-flap failures, infection, and additional procedures with no difference in other parameters. The largest majority of free flaps continue to be performed in a delayed time frame.

Free versus Pedicled Perforator Flaps for Lower Extremity Reconstruction: A Multicenter Comparison of Institutional Practices and Outcomes.

BACKGROUND: Of all body regions, lower extremity wounds have been and remain the greatest challenge. Perforator free flaps have been accepted as a reasonable option to solve this dilemma but require the complexity of microsurgery. As a consequence, the possibility that pedicled perforator flaps could supplant even perforator free flaps has recently gained intense enthusiasm. METHODS: A retrospective investigation was undertaken to compare the validity for the use of perforator flaps of all types at three dissimilar institutions, that is, a university, a regional center, and a community hospital. All flaps performed in the 5-year period, 2011 to 2015, were included to allow at least 1-year follow-up before data analysis. A total of 433 free perforator flaps and 52 pedicled perforator flaps had been performed specifically for the lower extremity. RESULTS: Patient demographics, wound etiology, and comorbidities were similar for all institutions. Free flaps were more commonly needed after trauma and for chronic ulcers. Pedicled flaps were more likely an option after tumor excision. Large defects or those involving the foot were better served by free flaps. Overall success for free perforator flaps was 90.1% and for pedicled perforator flaps was 92.3%, with no significant difference noted (p = 0.606) between institutions. Peripheral vascular disease was the only significant comorbidity risk factor for both free and pedicled flap failure. CONCLUSION: Perforator flaps in general have become a reasonable solution for soft tissue defects of the lower extremity. Following careful consideration of the etiology, dimensions, location, patient comorbidities, and presence of adequate perforators, a pedicled or free perforator flap could potentially be successful. Pedicled perforator flaps, if adequate healthy soft tissues remain adjacent to the defect, forecast a continuance of the evolution in seeking simplicity yet reliability by the best flap possible for soft tissue closure of the lower limb wound.