Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury.The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association.

• What is the role of physical examination and additional diagnostic tools?
• Which patient-related outcome measures should be used?
• What are the relevant parameters that influence the indication for an ACL reconstruction?
• Which findings or complaints are predictive of a bad result of an ACL injury treatment?
• What is the optimal timing for surgery for an ACL injury?
• What is the outcome of different conservative treatment modalities?
• Which kind of graft gives the best result in an ACL reconstruction?
• What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy?

These 8 questions were answered and recommendations were made, using the “Appraisal of Guidelines for Research and Evaluation” instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.Anterior cruciate ligament injury is a common sports injury with a worldwide reconstruction rate of more than 200,000 per year (Meuffels et al. 2011). Clinically practical guidelines have been used for a long time; the Dutch Orthopaedic Association has a long experience of guideline development, since the 1980s. This is the recommendation from the multidisciplinary clinical guideline “anterior cruciate ligament injury”, set up and aimed at all the members of the medical disciplines concerned with diagnosis and treatment of anterior cruciate ligament injury. This injury is seen by a large number of diverse medical caregivers, and the importance of a team approach to injury treatment with a view to reintegration in sport has been established. This guideline was set up using the “Appraisal of Guidelines for Research and Evaluation (AGREE)” instrument (www.agreecollaboration.org).     

The Effect of Gender and Fatigue on the Biomechanics of Bilateral Landings from a Jump: Peak Values

Female athletes are substantially more susceptible than males to suffer acute non-contact anterior cruciate ligament injury. A limited number of studies have identified possible biomechanical risk factors that differ between genders. The effect of fatigue on the biomechanics of landing has also been inadequately investigated. The objective of the study was to examine the effect of gender and fatigue on peak values of biomechanical variables during landing from a jump. Thirty-two recreational athletes performed bilateral drop jump landings from a 40 cm platform. Kinetic, kinematic and electromyographic data were collected before and after a functional fatigue protocol. Females landed with 9° greater peak knee valgus (p = 0.001) and 140% greater maximum vertical ground reaction forces (p = 0.003) normalized to body weight compared to males. Fatigue increased peak foot abduction by 1.7° (p = 0.042), peak rectus femoris activity by 27% (p = 0.018), and peak vertical ground reaction force (p = 0.038) by 20%. The results of the study suggest that landing with increased peak knee valgus and vertical ground reaction force may contribute to increased risk for knee injury in females. Fatigue caused significant but small changes on some biomechanical variables. Anterior cruciate ligament injury prevention programs should focus on implementing strategies to effectively teach females to control knee valgus and ground reaction force.

Key points

• Female athletes landed with increased knee valgus and VGRF which may predispose them to ACL injury.
• Fatigue elicited a similar response in male and female athletes.
• The effectiveness of sports injury prevention programs may improve by focusing on teaching females to land softer and with less knee valgus.

Key words: Anterior cruciate ligament injury, injury prevention, knee injury, sports biomechanics     

Whole Body Vibration Exercise Protocol versus a Standard Exercise Protocol after ACL Reconstruction: A Clinical Randomized Controlled Trial with Short Term Follow-Up

The suitability and effectiveness of whole body vibration (WBV) exercise in rehabilitation after injury of the anterior cruciate ligament (ACL) was studied using a specially designed WBV protocol. We wanted to test the hypothesis if WBV leads to superior short term results regarding neuromuscular performance (strength and coordination) and would be less time consuming than a current standard muscle strengthening protocol. In this prospective randomized controlled clinical trial, forty patients who tore their ACL and underwent subsequent ligament reconstruction were enrolled. Patients were randomized to the whole body vibration (n=20) or standard rehabilitation exercise protocol (n=20). Both protocols started in the 2^nd week after surgery. Isometric and isokinetic strength measurements, clinical assessment, Lysholm score, neuromuscular performance were conducted weeks 2, 5, 8 and 11 after surgery. Time spent for rehabilitation exercise was reduced to less than a half in the WBV group. There were no statistically significant differences in terms of clinical assessment, Lysholm score, isokinetic and isometric strength. The WBV group displayed significant better results in the stability test. In conclusion, preliminary data indicate that our whole body vibration muscle exercise protocol seems to be a good alternative to a standard exercise program in ACL-rehabilitation. Despite of its significant reduced time requirement it is at least equally effective compared to a standard rehabilitation protocol.

Key points

• In this prospective randomized controlled clinical trial, we tested the hypothesis if WBV leads to superior short term results regarding neuromuscular performance (strength and coordination) and would be less time consuming than a current standard muscle strengthening protocol in forty patients who underwent ACL reconstruction.
• Time spent for rehabilitation exercise was reduced to less than a half in the WBV group as compared to the standard exercise group. Both protocols showed no differences regarding clinical assessment, Lysholm score, isokinetic and isometric strength.
• Despite a more than 50% reduction in time spent for exercise sessions, the WBV group achieved significant better results in the stability test.
• In conclusion, the presented WBV program can be considered as a practical alternative to a standard exercise program during ACL-rehabilitation.

Key words: Knee injury, anterior cruciate ligament, rehabilitation, exercise protocol, neuromuscular performance     

Effects of an Injury Prevention Program on Anterior Cruciate Ligament Injury Risk Factors in Adolescent Females at Different Stages of Maturation

The ideal timing to implement anterior cruciate ligament injury prevention programs with respect to maturation is unclear. The purpose of this study was to investigate the effects of an injury prevention program on knee mechanics in early-, late-, and post-pubertal females. In the study, 178 adolescent female basketball players were assigned to six groups: early-pubertal training, early-pubertal control, late-pubertal training, and late-pubertal control, post-pubertal training, and post-pubertal control. The training groups performed an injury prevention program for six months. Medial knee displacement, knee flexion range of motion, and the probability of high knee abduction moment were assessed before and after the training period. After the six-month training period, medial knee displacement was significantly increased in the early-pubertal control group whereas it was unchanged in the early-pubertal training group. Knee flexion range of motion was significantly decreased in the early-pubertal control group whereas it did not change in the early-pubertal training group. The probability of high knee abduction moment was increased in the early-pubertal control group whereas it was unchanged in the earl-pubertal training group. The probability of high knee abduction moment was also decreased in the post-pubertal training group whereas it did not change in the post-pubertal control group. The program limited the development of high-risk movement patterns associated with maturation in early puberty while improving the knee mechanics in post-pubertal adolescents. Therefore, an injury prevention program should be initiated in early puberty and continue through the post-puberty years.Key points

• An ACL injury prevention program limited the development of high-risk movement patterns associated with maturation in early puberty while it improved the knee mechanics in post-pubertal adolescents.
• An improvement through a program might not be obvious due to the natural development of the faulty movement patterns in early-pubertal adolescents, while significant improvement through the training program can be expected in post-pubertal adolescents.
• An ACL injury prevention program should be initiated in early puberty and continue through the post-puberty years.

Key words: Knee injuries, landing, neuromuscular control, puberty     

Differences in Pivot Leg Kinematics and Electromyography Activation in Various Round House Kicking Heights

The round house kick (RHK) is a common technique in taekwondo (TKD). The kicking action originates from the dynamic stability of the pivot leg. However, some knee injuries are caused by more difficult kicking strategies, such as kicks to the opponent’s head. This study analyses the effects on TKD players in the lower extremity kinematic and neuromuscular reactions from different kicking heights. This study recruited 12 TKD players (age=20.3 ± 1.3 years, height = 1.72 ± 0.09 m, mass = 62.17 ± 9.45 kg) with no previous lower extremity ligament injuries. All athletes randomly performed 3 RHK at different heights (head, chest, and abdomen), repeating each kick 5 times. During the RHK action, the kinematics and muscle activations of the pivot leg were collected using six high-speed cameras and electromyography devices. The results found that during the RHK return period a high kicking position demonstrated larger knee valgus with the straight knee, and more hamstring activation on the pivot leg. The RHK pivot foot for TKD players encountered more risk of injury from high target kicking. The hamstring muscle played an important stabilizing role. It is recommended that sports medicine clinicians or sports coaches use this information to provide further protective injury prevention strategies.Key points

• Head position kicking will exhibit greater knee joint instability in the pivot leg during RHK, because TKD players must change the joint range of motion to add kicking range to increase their chance to score.
• BF and RF co-activation will promote pivot leg stability in RHK kicking, especially in the return phase, to avoid a more dangerous alignment.
• The RHK pivot foot for TKD players encountered greater risk for injury in high target kicking. The hamstring muscle played an important stabilizing role.

Key words: Taekwondo, anterior cruciate ligament injury, knee valgus, co-contraction activation     

A Hypothesis: Could Portable Natural Grass be a Risk Factor for Knee Injuries?

Previous study has shown a likely link between increased shoe- surface traction and risk of knee Anterior Cruciate Ligament (ACL) injury. Portable natural grass systems are being used more often in sport, but no study to date has investigated their relative safety. By their nature, they must have high resistance to falling apart and therefore newly laid systems may be at risk of creating excessive shoe-surface traction. This study describes two clusters of knee injuries (particularly non-contact ACL injuries), each occurring to players of one professional football team at single venue, using portable grass, in a short space of time. The first series included two ACL injuries, one posterolateral complex disruption and one lateral ligament tear occurring in two rugby league games on a portable bermudagrass surface in Brisbane, Australia. The second series included four non-contact ACL injuries over a period of ten weeks in professional soccer games on a portable Kentucky bluegrass/perennial ryegrass surface in Barcelona, Spain. Possible intrinsic risk factors are discussed but there was no common risk shared by the players. Although no measures of traction were made at the Brisbane venue, average rotational traction was measured towards the end of the injury cluster at Camp Nou, Barcelona, to be 48 Nm. Chance undoubtedly had a part to play in these clusters, but the only obvious common risk factor was play on a portable natural grass surface soon after it was laid. Further study is required to determine whether portable natural grass systems may exhibit high shoe-surface traction soon after being laid and whether this could be a risk factor for knee injury.

Key points

• Excessive shoe-surface traction is a hypothesised risk factor for knee ligament injuries, including anterior cruciate ligament injuries.
• Portable natural grass systems (by their nature in order to prevent grass rolls or squares from falling apart) will tend to exhibit high resistance to tearing when first laid. This may lead to excessive shoe-surface traction.
• This dual case series describes two clusters of non-contact knee ligament injuries which occurred in circumstances of newly laid portable turf.
• Further research is warranted to undercover any link between non-contact knee ligament injuries and ground surfaces conditions.

Key words: Anterior cruciate ligament, bermudagrass, perennial ryegrass, Kentucky bluegrass     

Is There a Sex Difference in Trunk Neuromuscular Control among Recreational Athletes during Cutting Maneuvers?

Trunk motion is most likely to influence knee joint injury risk, but little is known about sex-related differences in trunk neuromuscular control during changes of direction. The purpose of the present study was to test whether differences in trunk control between males and females during changes of direction exist. Twelve female and 12 male recreational athletes (with at least 10 years of experience in team sport) performed unanticipated changes of direction with 30° and 60° cut angles, while 3D trunk and leg kinematics, ground reaction forces and trunk muscles electromyography were recorded. Trunk kinematics at the time of peak knee abduction moment and directed co-contraction ratios for trunk muscles during the pre-activation and weight acceptance phases were determined. None of the trunk kinematics and co-contraction ratio variables, nor peak knee abduction moment differed between sexes. Compared to the 30° cut, trunk lateral flexion remained unchanged and trunk external rotation was reduced (p < 0.001; η²_p (partial eta squared for effect size) = 0.78), while peak knee abduction moment was increased (p < 0.001; η²_p = 0.84) at 60°. The sharper cutting angle induced muscle co-contraction during the pre-activation directed less towards trunk flexors (p < 0.01; η²_p = 0.27) but more towards trunk medial flexors and rotators opposite to the movement direction (p < 0.001; η²_p > 0.46). However, muscle co-contraction during the weight acceptance phase remained comparable between 30° and 60°. The lack of sex-related differences in trunk control does not explain knee joint injury risk discrepancies between sexes during changes of direction. Trunk neuromuscular strategies during sharper cutting angles revealed the importance of external oblique muscles to maintain trunk lateral flexion at the expense of trunk rotation. This provides new information for trunk strength training purposes for athletes performing changes of direction. Key points

• Trunk neuromuscular control is not different between males and females during unanticipated changes of direction.
• Sharper cutting angles increase knee joint loads and trunk neuromuscular activity during unanticipated changes of direction.
• Trunk neuromuscular strategy during sharper cutting angles is to avoid leaning forward too much prior to contact, while maintaining trunk lateral flexion at the expense of trunk rotation.
• External oblique muscles play an important role during unanticipated changes of direction.

Key words: Core stability, trunk lateral flexion, knee abduction moment, anterior cruciate ligament, co-contraction     

Is a Cognitive-Behavioural Biofeedback Intervention Useful to Reduce Injury Risk in Junior Football Players?

Athletes participating in sport are exposed to a relatively high injury risk. Previous research has suggested that it could be possible to reduce sports injuries through psychological skills training. The purpose of this study was to examine the extent to which a cognitive behavioural biofeedback intervention could reduce the number of sports injuries in a sample of players in Swedish elite football high schools. Participants from four elite football high schools (16-19 years old) were divided into one experiment (n = 13) and one control group (n = 14). Participants were asked to complete three questionnaires to assess anxiety level (Sport Anxiety Scale), history of stressors (Life Event Scale for Collegiate Athletes) and coping skills (Athletic Coping Skills Inventory - 28) in a baseline measure. Mann-Whitney U-tests showed no significant differences in pre-intervention scores based on the questionnaires. The experimental group participated in a nine-week intervention period consisting of seven sessions, including: somatic relaxation, thought stopping, emotions/problem focused coping, goal setting, biofeedback training as well as keeping a critical incident diary. A Mann-Whitney U test showed no significant difference between the control and experimental group U (n1 = 13, n2 = 14) = 51.00, p = 0.054. However, considering the small sample, the statistical power (0.05 for present study), to detect effects was low. The results of the study are discussed from a psychological perspective and proposals for future research are given.

Key points

• Cognitive-behavioral training together with biofeedback training seems to be an effective strategy to decrease the occurrence of injuries.
• More intervention studies should be conducted applying existing biofeedback methodology, especially in the injury preventive area.
• Future research should develop a bio-psychological injury model aimed at predicting injury occurrence which describes the physiological stress responses and how they can be measured in more detail.

Key words: Coping skills, elite sport, psychological injury prevention, psychological stress, soccer     

Lower Extremity Malalignments and Anterior Cruciate Ligament Injury History

To identify if lower extremity malalignments were associated with increased propensity of a history of anterior cruciate ligament (ACL) ruptures in males and females using a case control design. Twenty subjects (10 males, 10 females) had a history of ACL injury and twenty (10 males, 10 females) had no history of ACL injury. Subjects were assessed for navicular drop, quadriceps angle, pelvic tilt, hip internal and external rotation range of motion, and true and apparent leg length discrepancies. Statistical analysis was performed to identify differences in these measures in regard to injury history and gender, and to identify if any of these measures were predictive of ACL injury history. Increased navicular drop and anterior pelvic tilt were found to be statistically significant predictors of ACL injury history regardless of gender. Limbs that had previously suffered ACL ruptures were found to have increased navicular drop and anterior pelvic tilt compared to uninjured limbs. Based on the results of this retrospective study, the lower extremity malalignments examined do not appear to predispose females to tearing their ACLs more than males.

Key Points

• Hyperpronation and greater anterior pelvic tilt were the two malalignments most associated with history of ACL injury.
• Females had larger quadriceps angles than males, but this measure was not significantly related to ACL injury history.
• Not all structural differences between genders help explain the increased risk of ACL injuries in female athletes.

Key Words: Hyperpronation, navicular drop, quadriceps angle     

Design and implementation of a neuromuscular training program following anterior cruciate ligament reconstruction.

Neuromuscular training programs are increasingly integrated into clinical practice for lower extremity rehabilitation. A few rehabilitation programs have been evaluated for patients with anterior cruciate ligament (ACL) deficiency and for injury prevention, but there is limited scientific evidence of the effect of neuromuscular training following ACL reconstruction. Therefore, a neuromuscular training program was developed for patients after ACL reconstruction. The objective of the neuromuscular training was to improve the ability to generate a fast and optimal muscle firing pattern, to increase dynamic joint stability, and to relearn movement patterns and skills necessary during activities of daily living and sports activities. The main areas considered when designing the postoperative rehabilitation program after ACL reconstruction were: ACL graft healing and ACL strain values during exercises, proprioception and neuromuscular control, and clinical studies on the effect of neuromuscular training programs. The rehabilitation program consists of balance exercises, dynamic joint stability exercises, jump training/plyometric exercises, agility drills, and sport-specific exercise. The patients exercise 3 times a week for 6 months. The scientific and clinical evidence for the rehabilitation program are described and the main exercises in the program are outlined.     

The Effectiveness of Electromyographic Biofeedback as Part of a Meniscal Repair Rehabilitation Programme

The objective of the study was to assess the effectiveness of using electromyographic biofeedback in the early stages of rehabilitation after meniscal repair. In this randomised, controlled, parallel group study, the evolution of patients with meniscal lesions treated by meniscal suture who received (study group, n = 33) or did not receive (control group, n = 31) electromyographic biofeedback as part of their early rehabilitation programme has been compared. A total of 64 patients with previous meniscal repair participated in the study. The patients received a baseline assessment (after 1 postoperative week) and a follow-up (after 8 postoperative weeks) consisting of surface electromyography, dynamometry of thigh muscles and the assessment of the Knee injury and Osteoarthritis Outcome Score (KOOS). The electrical potential in contraction and the speed for contraction and relaxation for all monitored muscles increased significantly in the study group (p < 0.05). The difference between groups in the assessed score was significant for sport and recreational function (p < 0.05). The strength of the thigh muscles was not significantly influenced by the introduction of electromyographic biofeedback (EMG- BFB) in the rehabilitation programme. Electromyographic biofeedback helped patients to control their muscles after meniscal repair to accomplish physical activities that require better neuromuscular coordination and control. For these reasons, one may consider electromyographic biofeedback as an important component of rehabilitation after meniscal repair.

Key Points

• Exercises during the early phases of rehabilitation after meniscal repair are difficult to perform because of pain, oedema, and possibly a disruption in normal joint receptor activity.
• Electromyographic biofeedback is a painless, non-invasive method that can be used in muscle recovery after meniscal repair and enhances the rehabilitation process, especially related to muscular function.
• The rehabilitation programme that includes electromyographic biofeedback after meniscal repair increased the speed of muscle response to acoustic stimulation in both the initiation of contraction (onset time) and relaxation (offset time) and, also, the capacity of performing some specific physical acti-vities after 8 weeks of rehabilitation (according to KOOS values).
• Electromyographic biofeedback is not responsible for the decrease in pain, swelling or other postoperative symptoms but it is important in order to help the patient to conduct the activities which require neuromuscular coordination and muscle control.

Key words: Knee, injury, physical therapy     

The Lower Extremity Biomechanics of Single- and Double-Leg Stop-Jump Tasks

The anterior cruciate ligament (ACL) injury is a common occurrence in sports requiring stop-jump tasks. Single- and double-leg stop-jump techniques are frequently executed in sports. The higher risk of ACL injury in single-leg drop landing task compared to a double-leg drop landing task has been identified. However the injury bias between single- and double-leg landing techniques has not been investigated for stop-jump tasks. The purpose of this study was to determine the differences between single- and double-leg stop-jump tasks in knee kinetics that were influenced by the lower extremity kinematics during the landing phase. Ground reaction force, lower extremity kinematics, and knee kinetics data during the landing phase were obtained from 10 subjects performing single- and double-leg stop-jump tasks, using motion-capture system and force palates. Greater peak posterior and vertical ground reaction forces, and peak proximal tibia anterior and lateral shear forces (p < 0.05) during landing phase were observed of single-leg stop-jump. Single-leg stop-jump exhibited smaller hip and knee flexion angle, and knee flexion angular velocity at initial foot contact with the ground (p < 0.05). We found smaller peak hip and knee flexion angles (p < 0.05) during the landing phase of single-leg stop-jump. These results indicate that single-leg landing may have higher ACL injury risk than double-leg landing in stop-jump tasks that may be influenced by the lower extremity kinematics during the landing phase.

Key points

• Non-contact ACL injuries are more likely to occur during the single-leg stop-jump task than during the double-leg stop-jump task.
• Single-leg stop-jump exhibited greater peak proximal tibia anterior and lateral shear forces, and peak posterior and vertical ground reaction forces during the landing phase than the double-leg stop-jump task.
• Single-leg stop-jump exhibited smaller hip flexion angle, knee flexion angle, and knee flexion angular velocity at initial foot contact with the ground.
• Single-leg stop-jump exhibited greater peak knee extension and valgus moment during the landing phase than the double-leg stop-jump task.
• Single-leg stop-jump extended the hip joint at initial foot contact with the ground.

Key words: Anterior cruciate ligament, kinematics, kinetics, ground reaction force     

Neuromuscular electrical stimulation after anterior cruciate ligament surgery

This randomized, double blind, controlled trial was designed to determine the effectiveness of neuromuscular electrical stimulation of the knee extensor and flexor muscles in the prevention of muscular weakening after anterior cruciate ligament surgery. Neuromuscular electrical stimulation treatment was given in addition to an early exercise therapy regimen and compared with an early exercise therapy regimen alone. Forty-nine patients after anterior cruciate ligament surgery were assigned randomly either to a neuromuscular electrical stimulation and exercise group, a transcutaneous electrical nerve stimulation as analgesic and exercise group, or an exercise alone group as control. All groups received a standard regimen of rehabilitation after anterior cruciate ligament surgery. The neuromuscular electrical stimulation and transcutaneous electrical nerve stimulation group additionally received electrical stimulation during the first 6 weeks after surgery. Patients were measured for isometric and isokinetic torque in the knee extensor and flexor muscles after 6, 12, and 52 weeks. No statistical difference among groups was observed. It is concluded that neuromuscular electrical stimulation in combination with an early exercise therapy regimen is not significantly more effective in reducing weakening than an early exercise therapy regimen alone after anterior cruciate ligament surgery.     

Differential neuromuscular training effects onACL injury risk factors in"high-risk" versus "low-risk" athletes

Background  

Neuromuscular training may reduce risk factors that contribute to ACL injury incidence in female athletes. Multi-component, ACL injury prevention training programs can be time and labor intensive, which may ultimately limit training program utilization or compliance. The purpose of this study was to determine the effect of neuromuscular training on those classified as "high-risk" compared to those classified as "low-risk." The hypothesis was that high-risk athletes would decrease knee abduction moments while low-risk and control athletes would not show measurable changes.     

Mechanisms of the Anterior Cruciate Ligament Injury in Sports Activities: A Twenty-Year Clinical Research of 1,700 Athletes

The mechanisms of anterior cruciate ligament (ACL) injuries are still inconclusive from an epidemiological standpoint. An epidemiological approach in a large sample group over an appropriate period of years will be necessary to enhance the current knowledge of the ACL injury mechanism. The objective of the study was to investigate the ACL injury occurrence in a large sample over twenty years and demonstrate the relationships between the ACL injury occurrence and the dynamic knee alignment at the time of the injury. We investigated the activity, the injury mechanism, and the dynamic knee alignment at the time of the injury in 1,718 patients diagnosed as having the ACL injuries. Regarding the activity at the time of the injury, “competition ”was the most common, accounting for about half of all the injuries. The current result also showed that the noncontact injury was the most common, which was observed especially in many female athletes. Finally, the dynamic alignment of “Knee-in & Toe- out ”(i.e. dynamic knee valgus) was the most common, accounting for about half. These results enhance our understanding of the ACL injury mechanism and may be used to guide future injury prevention strategies.

Key points

• We investigated the situation of ACL injury occurrence, especially dynamic alignments at the time of injury, in 1,718 patients who had visited our institution for surgery and physical therapy for twenty years.
• Our epidemiological study of the large patient group revealed that “knee-in & toe-out ”alignment was the most frequently seen at the time of the ACL injury.
• From an epidemiological standpoint, we need to pay much attention to avoiding “Knee-in & Toe-out ”alignment during sports activities.

Key words: Anterior cruciate ligament, injury mechanism, dynamic alignment, prevention     

The Influence of a Foot Orthotic on Lower Extremity Transverse Plane Kinematics in Collegiate Female Athletes with Pes Planus

Non-contact anterior cruciate ligament (ACL) injuries in female athletes remain prevalent. Athletes with excessive foot pronation have been identified to be at greater risk for non-contact ACL injury. Excessive foot pronation has been linked to increased medial tibial rotation. Increased medial tibial rotation heightens ACL strain and has been observed at or near the time of ACL injury. Foot orthotics have been shown to decrease medial tibial rotation during walking and running tasks. The effect of a foot orthotic on activities that simulate a non-contact ACL injury mechanism (i.e. landing) however is unknown. Therefore, the objective of this study was to determine whether a foot orthotic was capable of altering transverse plane lower extremity kinematics in female athletes during landing. Twenty uninjured collegiate female athletes participating in the sports of basketball, soccer or volleyball with pes planus volunteered. Utilizing a repeated measures counterbalanced design, subjects completed two landing tasks with and without a foot orthotic using standardized footwear. The prefabricated orthotic had a rigid shell and a 6 extrinsic rear-foot varus post. Dependent measures included initial contact angle, peak angle, excursion and time to peak angle for both the tibia and femur. Statistical analysis suggested that the selected foot orthosis had little influence over lower extremity transverse plane kinematics. Several factors including: the limitation of a static measure to predict dynamic movement, inter-subject variability and the physical characteristics of the orthotic device likely account for the results. Future research should examine the influence of different types of foot orthotics not only on lower extremity kinematics but also tibiofemoral kinetics.

Key Points

• Lower extremity transverse plane kinematics in female athletes during a landing task exhibit substantial variability.
• A rigid prefabricated foot orthotic does not significantly alter transverse plane lower extremity kinematics in female athletes with a navicular drop of at least 8mm.
• Additional study is necessary before firm conclusions regarding the influence of an orthotic device on lower extremity kinematics, kinetics, neuromuscular control and ultimately injury rates can be made.

Key words: ACL, hyperpronation, intervention, navicular drop, pes planus     

Knee kinematics and kinetics in former soccer players with a 16-year-old ACL injury – the effects of twelve weeks of knee-specific training

Background  

Training of neuromuscular control has become increasingly important and plays a major role in rehabilitation of subjects with an injury to the anterior cruciate ligament (ACL). Little is known, however, of the influence of this training on knee stiffness during loading. Increased knee stiffness occurs as a loading strategy of ACL-injured subjects and is associated with increased joint contact forces. Increased or altered joint loads contribute to the development of osteoarthritis.     

In Vivo Motion of Femoral Condyles During Weight-Bearing Flexion After Anterior Cruciate Ligament Rupture Using Biplane Radiography

The purpose of this study was to investigate in vivo three- dimensional tibiofemoral kinematics and femoral condylar motion in knees with anterior cruciate ligament (ACL) deficiency during a knee bend activity. Ten patients with unilateral ACL rupture were enrolled. Both the injured and contralateral normal knees were imaged using biplane radiography at extension and at 15°, 30°, 60°, 90°, and 120° of flexion. Bilateral knees were next scanned by computed tomography, from which bilateral three-dimensional knee models were created. The in vivo tibiofemoral motion at each flexion position was reproduced through image registration using the knee models and biplane radiographs. A joint coordinate system containing the geometric center axis of the femur was used to measure the tibiofemoral motion. In ACL deficiency, the lateral femoral condyle was located significantly more posteriorly at extension and at 15° (p < 0.05), whereas the medial condylar position was changed only slightly. This constituted greater posterior translation and external rotation of the femur relative to the tibia at extension and at 15° (p < 0.05). Furthermore, ACL deficiency led to a significantly reduced extent of posterior movement of the lateral condyle during flexion from 15° to 60° (p < 0.05). Coupled with an insignificant change in the motion of the medial condyle, the femur moved less posteriorly with reduced extent of external rotation during flexion from 15° to 60° in ACL deficiency (p < 0.05). The medial- lateral and proximal-distal translations of the medial and lateral condyles and the femoral adduction-abduction rotation were insignificantly changed after ACL deficiency. The results demonstrated that ACL deficiency primarily changed the anterior-posterior motion of the lateral condyle, producing not only posterior subluxation at low flexion positions but also reduced extent of posterior movement during flexion from 15° to 60°.

Key Points

• Three-dimensional tibiofemoral kinematics and femoral condylar motion in ACL-deficient knees during upright weight-bearing flexion were measured using biplane radiography with the geometric center axis.
• ACL deficiency caused posterior subluxation of the lateral condyle with excess external femoral rotation at early flexion positions.
• On flexion from 15° to 60°, the lateral condyle moved slightly posteriorly in ACL deficiency leading to reduced extent of external femoral rotation.

Key words: anterior cruciate ligament, injury, kinematics, tibiofemoral, femoral condyle, radiography     

Improving Functional Performance and Muscle Power 4-to-6 Months After Anterior Cruciate Ligament Reconstruction

The purpose of this study was to examine the effects of 8-week retraining programs, with either two or three training sessions per week, on measures of functional performance and muscular power in athletes with anterior cruciate ligament reconstruction (ACLR). Sixteen male athletes were randomly assigned to two groups after ACLR: a functional training group (FTG, n = 8) training 2 intense sessions per week (4hrs/week), and a control group (CG, n = 8) training 3 sessions per week with moderate intensity (6hrs/week). The two groups were assessed at four and six months post-ACLR and the effects of retraining were measured using the following assessments: the functional and the muscular power tests, and the agility T-test. After retraining, the FTG had improved more than the CG in the operated leg in the single leg hop test (+34.64% vs. +10.92%; large effect), the five jump test (+8.87% vs. +5.03%; medium effect), and single leg triple jump (+32.15% vs. +16.05%; medium effect). For the agility T-test, the FTG had larger improvements (+17.26% vs. +13.03%, medium effect) as compared to the CG. For the bilateral power tests, no significant training effects were shown for the two groups in the squat jump (SJ), the counter movement jump (CMJ) and the free arms CMJ (Arm CMJ). On the other hand, the unilateral CMJ test with the injured and the uninjured legs showed a significant increase for the FTG with respect to CG (p < 0.05). The present study introduces a new training modality in rehabilitation after ACLR that results in good recovery of the operated limb along with the contra-lateral leg. This may allow the athletes to reach good functional and strength performance with only two physical training sessions per week, better preparing them for a return to sport activity at 6 months post- ACLR and eventually sparing time for a possible progressive introduction of the sport specific technical training.

Key points

• Functional training (plyometrics, neuromuscular, proprioceptive and agility exercises) in athletes during 4th to 6th months post-ACLR further improved functional outcomes, compared to a conventional rehabilitation program.
• The former program was more time-efficient compared to the latter one as indicated by the weekly training duration (4hrs/week vs. 6hrs/week).
• This study provides evidence of the functional training in knee rehabilitation and provides important information that is highly relevant to clinicians, physiotherapists, coaches and trainers who are in charge of the injured athletes during the later phase of the rehabilitation after ACLR.

Key words: ACL reconstruction, knee injury, retraining, agility, strength testing, power testing