Dynamic Stability Of Knee Joint Research Articles

A clinical practice review of therapeutic movement-based anterior cruciate ligament reconstruction return to sports bridge program: the biological, biomechanical and behavioral rationale.

This clinical practice review describes the biological, biomechanical and behavioral rationale behind a return to sport bridge program used predominantly with non-elite, youth and adolescent high school and college athletes following anterior cruciate ligament (ACL) reconstruction. Post-physiotherapy, this program has produced outcomes that meet or exceed previous reports. With consideration for athletic identity and the Specific Adaptations to Imposed Demands (SAID) principle, the early program focus was on restoring non-impaired bilateral lower extremity joint mobility and bi-articular musculotendinous extensibility. Building on this foundation, movement training education, fundamental bilateral lower extremity strength and power, and motor learning was emphasized with use of external focus cues and ecological dynamics-social cognition considerations. Plyometric and agility tasks were integrated to enhance fast twitch muscle fiber recruitment, anaerobic metabolic energy system function, and fatigue resistance. The ultimate goal was to achieve the lower extremity neuromuscular control and activation responsiveness needed for bilateral dynamic knee joint stability. The rationale and conceptual basis of selected movement tasks and general philosophy of care concepts are described and discussed in detail. Based on the previously reported efficacy of this movement-based therapeutic exercise program we recommend that supplemental programs such as this become standard practice following release from post-surgical physiotherapy and before return to sports decision-making.

Effect of Mobilization with Movement and Kinesio Taping on Knee Function and Pain in Gonarthrosis

Background. Gonarthrosis is one of the most common diseases of the musculoskeletal system. As the disease progresses, the patient’s social and physical activities change. Reliable and effective therapies that slow the progression of gonarthrosis have not yet been found. There is a lack of evidence that a short course of physiotherapy and exercise-based treatment is effective or of how mobilization with movement and kinesio taping affects knee function and pain. We believe that in patients with knee gonarthrosis, the positive effects of physiotherapy combined with mobilization with movement and kinesio taping on knee functions and pain will be better than in those subjects who received only traditional physiotherapy.
 Aim. To determine the effect of mobilization with movement and kinesio taping on knee function parameters and pain in gonarthrosis.
 Methods. The study included 22 people diagnosed with gonarthrosis. For the experimental group (n=11), physiotherapy exercise, mobilization with movement and kinesiotape were applied, whereas the control group (n=11) used only physiotherapy exercise procedures. Subjects were evaluated for pain intensity, active knee range of motion, dynamic knee joint stability and evaluation of thigh muscle strength.
 Results. In the experimental group, there was a significant decrease in pain after 7 days and a significant difference with control group. Significant knee flexion results were recorded in the experimental group and significant knee extension results were recorded in the control group. In the experimental group, the dynamic knee joint stabilization significantly increased after 14 days. The strength of the thigh muscles was significantly increased in the experimental group after 14 days.
 Conclusion. The effect of mobilization with movement and kinesio taping of knee function, dynamic stability pain improving functional performance of dynamic stability was more significant than an exercise program lasting two weeks in subjects with knee gonarthrosis.
 Keywords: gonarthrosis, mobilization with movement, kinesio taping.

Vertical stiffness is not related to anterior cruciate ligament elongation in professional rugby union players

BackgroundNovel research surrounding anterior cruciate ligament (ACL) injury is necessary because ACL injury rates have remained unchanged for several decades. An area of ACL risk mitigation which has not been...

ACL injury risk in elite female youth soccer: Changes in neuromuscular control of the knee following soccer-specific fatigue.

Fatigue is known to influence dynamic knee joint stability from a neuromuscular perspective, and electromechanical delay (EMD) plays an important role as the feedback activation mechanism that stabilizes the joint. The aim of this study was to investigate the influence of soccer-specific fatigue on EMD in U13-, U15-, and U17-year-old female soccer players. Thirty-six youth soccer players performed eccentric actions of the hamstrings in a prone position at 60, 120, and 180°/s before and after a soccer-specific fatigue trial. Surface electromyography was used to determine EMD from the semitendinosus, biceps femoris and gastrocnemius. A time × age × muscle × velocity repeated measures analysis of variance was used to explore the influence of fatigue on EMD. A significant main effect for time (P = 0.001) indicated that EMD was significantly longer post- compared with pre-fatigue (58.4% increase). A significant time × group interaction effect (P = 0.046) indicated EMD was significantly longer in the U13 age group compared with the U15 (P = 0.011) and U17 (P = 0.021) groups and greater post-fatigue. Soccer-specific fatigue compromised neuromuscular feedback mechanisms and the age-related effects may represent a more compliant muscle-tendon system in younger compared with older girls, increasing risk of injury.

Mechanisms and Risk Factors for Noncontact ACL Injury in Age Mature Athletes Who Engage in Field Or Court Sports

Epidemiological data show that in the last 10 years alone the incidence and rate of anterior cruciate ligament (ACL) injuries have not changed appreciably. Furthermore, many ACL injuries appear to be noncontact in nature and sustained while engaging in some field or court sport. Thus, the need to investigate novel methods and adopt training strategies to prevent ACL injuries is paramount. To do so, however, requires an understanding of the mechanisms and risk factors for the injury. The aim of this review was to investigate the mechanisms and risk factors for noncontact ACL injuries in age mature athletes who compete in field or court sports. A search of the entire MEDLINE database for biomedicine was performed, and an iterative reference check was also conducted. A total of 87 articles disclosed met the eligibility criteria. Articles were grouped into 'themes'; 'anatomical and biomechanical mechanisms and risk factors,' 'intrinsic mechanisms and risk factors,' and 'extrinsic mechanisms and risk factors.' In this review, it is concluded that there are still a number of risk factors and mechanisms for noncontact ACL injury that are not well understood. However, the importance of dynamic knee joint stability is highlighted. It is also suggested that novel methods for preventing ACL injury be investigated and developed.

The effects of hypohydration and fatigue on neuromuscular activation performance

This study investigated the effects of hypohydration by fluid restriction on voluntary and evoked indices of neuromuscular performance at a functional joint angle. Measures of static volitional peak force (2-3-s maximal muscle actions) and evoked peak twitch force, electromechanical delay, and rate of force development were obtained from the knee extensors (30° knee flexion) of 10 males (age, 24 (4) years; height, 1.76 (0.10) m; body mass, 78.7 (9.13) kg (mean (SD))) prior to and immediately following 24 h of (i) euhydration (EU) and (ii) hypohydration (HYP). Neuromuscular performance was also assessed in response to a fatiguing task (3 × 30-s maximal static knee extensions) following each condition. Repeated-measures ANOVAs showed that HYP was associated with a significant 2.1% loss in body mass (p < 0.001) and a 7.8% reduction in volitional peak force (p < 0.05). Following fatigue, data indicated statistically similar levels of impairment to volitional peak force (11.6%, p < 0.01) and rate of force development (21.0%, p < 0.01) between conditions (EU; HYP). No changes to any other indices of performance were observed. The substantive hypohydration-induced deficits to muscle strength at this functional joint angle might convey a decreased performance capability and should be considered by the hypohydrated athlete. Whilst hypohydration did not affect fatigue-related performance of the knee extensors, the additive changes associated with lower baseline levels of strength performance (7.8%) and fatigue (11.6%) coupled with slower rate of muscle force production (from 0-100 ms) following fatigue may present significant challenges to the maintenance of dynamic knee joint stability, particularly at this vulnerable joint position.

Does higher anterior knee joint laxity alter landing biomechanics in pubescent girls? Implications for non-contact ACL ruptures

Introduction: From the onset of puberty females are at a greater risk of sustaining a non-contact anterior cruciate ligament (ACL) rupture compared to males. Increased anterior knee laxity (AKL) in females has been proposed as a possible cause of this increased ACL injury risk, due to the associated decrease in dynamic knee joint stability during movements such as landing. Despite this association, there is a dearth of literature investigating the effects of increased AKL on lower limb landing biomechanics in adolescent girls.

Hamstring force control following ACL injury and reconstruction and its relation to quadriceps coactivation and dynamic knee joint stability

Introduction: Typically, isokinetic muscle performance is assessed by measuring the peak or angle-specific torque; yet, another distinct aspect of muscle performance relates to torque steadiness—that is, the ability to control muscle force output. Following anterior cruciate ligament (ACL) injury and surgery, hamstrings force steadiness may reflect dynamic joint stability. Procurement of the combined semitendinosus and gracilis tendon (STGT) graft as an ACL substitute – because the insult incurred to the medial hamstring musculotendinous unit – may potentially alter the hamstrings ability to control muscle force output.

Update on rehabilitation following ACL reconstruction

As anterior cruciate ligament (ACL) reconstruction has evolved to less invasive, more anatomical approaches, rehabilitation of the injured athlete has likewise become more progressive and innovative, with a sound understanding of graft and fixation strength and biologic healing-remodeling constraints. This review discusses these innovations including specific considerations before surgery, when planning rehabilitation timetables, and the importance of reestablishing nonimpaired active and passive knee range of motion and biarticular musculotendinous extensibility in positions of function. Concepts of self-efficacy or confidence and reestablishing the "athlete role" are also addressed. Since ACL injury and reinjury are largely related to the influence of structure-form-function on dynamic knee joint stability, the interrelationships between sensorimotor, neuromuscular, and conventional resistance training are also discussed. Although pivot shift "giving way" relates to function loss following ACL injury, anterior translational laxity often does not. Although there is growing evidence that progressive eccentric training may benefit the patient following ACL reconstruction, there is less evidence supporting the use of functional ACL knee braces. Of considerable importance is selecting and achieving a criteria-based progression to sports-specific training, reestablishing osseous homeostasis and improved bone density, blending open and closed kinetic chain exercises at the appropriate time period, and appreciating the influence of the trunk, upper extremities, and sports equipment use on knee loads. We believe that knee dysfunction and functional recovery should be considered from a local, regional, and global perspective. These concepts are consolidated into our approach to prepare patients for return to play including field testing and maintenance training.

Fatigue Effects on Knee Joint Stability During Two Jump Tasks in Women

Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 +/- 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes.

Comparison of hamstring neuromechanical properties between healthy males and females and the influence of musculotendinous stiffness

The hamstrings limit anterior cruciate ligament (ACL) loading, and neuromuscular control of these muscles is crucial for dynamic knee joint stability. Sex differences in electromechanical delay (EMD) and rate of force production (RFP) have been reported previously, and attributed to differences in musculotendinous stiffness (MTS). These characteristics define the neuromechanical response to joint perturbation, and sex differences in these characteristics may contribute to the greater female ACL injury risk. However, it is unclear if these differences exist in the hamstrings, and the relationship between MTS and neuromechanical function has not been assessed directly. Hamstring MTS, EMD, the time required to produce 50% peak force (Time50%), and RFP were assessed in 20 males and 20 females with no history of ACL injury. EMD did not differ significantly across sex ( p = 0.788). However, MTS ( p < 0.001) and RFP ( p = 0.003) were greater in males, Time50% ( p = 0.013) was shorter in males, and Time50% was negatively correlated with MTS ( r = −0.332, p = 0.039). These results suggest that neuromechanical hamstring function in females may limit dynamic knee joint stability, potentially contributing to the greater female ACL injury risk. However, future research is necessary to determine the direct influences of MTS and neuromechanical function on dynamic knee joint stability and ACL injury risk.

A simple acceleration model used to assess the dynamic stability of knee joint in ACL injured patients

A simple acceleration model used to assess the dynamic stability of knee joint in ACL injured patients

Valgus knee motion during landing in high school female and male basketball players.

The purpose of this study was to utilize three-dimensional kinematic (motion) analysis to determine whether gender differences existed in knee valgus kinematics in high school basketball athletes when performing a landing maneuver. The hypothesis of this study was that female athletes would demonstrate greater valgus knee motion (ligament dominance) and greater side-to-side (leg dominance) differences in valgus knee angle at landing. These differences in valgus knee motion may be indicative of decreased dynamic knee joint control in female athletes. Eighty-one high school basketball players, 47 female and 34 male, volunteered to participate in this study. Valgus knee motion and varus-valgus angles during a drop vertical jump (DVJ) were calculated for each subject. The DVJ maneuver consisted of dropping off of a box, landing and immediately performing a maximum vertical jump. The first landing phase was used for the analysis. Female athletes landed with greater total valgus knee motion and a greater maximum valgus knee angle than male athletes. Female athletes had significant differences between their dominant and nondominant side in maximum valgus knee angle. The absence of dynamic knee joint stability may be responsible for increased rates of knee injury in females but is not normally measured in athletes before participation. No method for accurate and practical screening and identification of athletes at increased risk of ACL injury is currently available to target those individuals that would benefit from neuromuscular training before sports participation. Prevention of female ACL injury from five times to equal the rate of males would allow tens of thousands of young females to avoid the potentially devastating effects of ACL injury on their athletic careers.

A new concept for isokinetic hamstring: quadriceps muscle strength ratio.

Conventionally, the hamstring:quadriceps strength ratio is calculated by dividing the maximal knee flexor (hamstring) moment by the maximal knee extensor (quadriceps) moment measured at identical angular velocity and contraction mode. The agonist-antagonist strength relationship for knee extension and flexion may, however, be better described by the more functional ratios of eccentric hamstring to concentric quadriceps moments (extension), and concentric hamstring to eccentric quadriceps moments (flexion). We compared functional and conventional isokinetic hamstring: quadriceps strength ratios and examined their relation to knee joint angle and joint angular velocity. Peak and angle-specific (50 degrees, 40 degrees, and 30 degrees of knee flexion) moments were determined during maximal concentric and eccentric muscle contractions (10 degrees to 90 degrees of motion; 30 and 240 deg/sec). Across movement speeds and contraction modes the functional ratios for different moments varied between 0.3 and 1.0 (peak and 50 degrees), 0.4 and 1.1 (40 degrees), and 0.4 and 1.4 (30 degrees). In contrast, conventional hamstring:quadriceps ratios were 0.5 to 0.6 based on peak and 50 degrees moments, 0.6 to 0.7 based on 40 degrees moment, and 0.6 to 0.8 based on 30 degrees moment. The functional hamstring:quadriceps ratio for fast knee extension yielded a 1:1 relationship, which increased with extended knee joint position, indicating a significant capacity of the hamstring muscles to provide dynamic knee joint stability in these conditions. The evaluation of knee joint function by use of isokinetic dynamometry should comprise data on functional and conventional hamstring:quadriceps ratios as well as data on absolute muscle strength.

Activity in receptor afferents from the anterior cruciate ligament evokes reflex effects on fusimotor neurones

Responses from 2–4 muscle spindle afferents from triceps surae and/or posterior biceps and semitendinosus muscles were simultaneously recorded in cats anaesthetized with α-chloralose. It was demonstrated that stretch of the anterior cruciate ligament (ACL) of the ipsilateral knee causes changes in dynamic and/or static sensitivity of primary and secondary spindle afferents to sinusoidal stretching. The changes were due to reflex actions of stretch/tension-sensitive receptor afferents from ACL on dynamic and static fusimotor neurones. The findings support the hypothesis that ACL-afferents contribute to the regulation of muscular stiffness around the knee, and thereby also to dynamic knee joint stability.