Kinetics of the lower limb during two typical Tai Chi movements in the elderly

Tai Chi (TC) is a recommended exercise for elderly people; however, its loading on the joints of the lower limbs is unknown. This study examined the 3D kinetics of the lower limbs during two typical TC movements and walking in the elderly. Fifteen experienced TC practitioners participated. Ground reaction forces, joint moments and time-to-peak joint moment generation were analysed. Compared with walking, both TC movements generated significantly (1) smaller peak ground reaction forces in all directions, except the anterior; (2) larger hip extension, adduction and internal rotational moments, knee adduction/abduction and internal rotation moments and eversion/inversion and external/internal moments of ankle–foot; and (3) longer peak moment generation time for hip extension, adduction and internal rotation, knee extension and ankle dorsiflexion and inversion. The TC loading patterns are consistent with the mechanical behaviour of biological tissues, which could help to strengthen the lower extremities and prevent falls in the elderly.     

Comparison of knee biomechanical characteristics during exercise between pinnacle and step trainers

BackgroundA novel stair-climber called a pinnacle trainer (PT) provides both sagittal and frontal plane exercise, making it different from a step trainer (ST), which provides only sagittal plane exercise. Exercise with different trajectories may produce different biomechanical responses. There are currently no guidelines for choosing between a PT and a ST for different training or rehabilitation purposes.Research questionsAre there differences in the electromyographic patterns of lower extremity musculature and biomechanical responses of the knee joint during exercise between using a PT and a ST?MethodsThis study utilizes a prospective observational study design. Eighteen healthy males participated in the study. A six-axis force and torque transducer embedded in the machine pedal synchronized with a three-dimensional motion capture system were utilized to measure kinematic and kinetic data of the right knee during the stepping movement. The activities of six lower extremity muscles of the same limb were captured with surface electromyography during exercise on the two trainer types.ResultsThe co-activation index of the vastus lateralis (VL) and the biceps femoris (BF) recorded during ST exercise was significantly greater than that for the PT exercise. Moreover, exercise using the ST produced a significantly greater knee downward force compared to that for the PT. Exercise with the PT produced a significantly greater internal knee varus moment compared to that for the ST.SignificanceThe ST provided greater co-activation of the BF and VL and a greater knee joint downward force, which may decrease the antero-posterior displacement of the tibia relative to the femur. Exercise with the PT produced a significant internal knee varus moment and a more balanced muscular activation on the vastus medialis and VL compared to that for the ST, which may decrease the maltracking of the patella.     

Gender differences in the knee joint loadings during gait

BackgroundThe differences in anatomical structure between men and women are widely known. Unfortunately, the influence of gender on the biomechanics of a healthy knee joint during gait is still poorly understood.Research questionThe aim of the presented study was to determine loads acting in the knee joint during gait, based on the observation of a large group of healthy young adults, in particular to determine the influence of gender on values of forces and moments and their time characteristics during gait cycle.MethodsTime-spatial gait parameters and ground reaction force were registered for 86 persons (43 females and 43 males) using a motion capture system and force plates. The numerical simulation with the AnyBody system was used to estimate loadings acting in the knee joint. Differences between women and men were tested using the unpaired Student's t-test with a Bonferroni correction.ResultsThe maximum values of loadings acting in the knee joint were: 411.1 %BW (body weight) for resultant force, 390.6 %BW for proximo-distal force, 110.8 %BW for antero-posterior force, 77.0 %BW for medio-lateral force, 2.63 %BWh (body weight times height) for flexion/extension moment, 0.97 %BWh for internal/external rotation moment and 5.7 %BWh for abduction/adduction moment. In general, the normalised forces were greater in the male group, while the normalised external moments acting on the knee were greater in the female group. Local extrema of forces during the stance phase were observed earlier for women.SignificanceKnowledge about gender differences in loadings acting in the knee joint can be of great importance in the case of detecting the early stages of gait abnormalities and treatment planning.     

Biomechanics during exercise with a novel stairclimber

The current study aimed to investigate the stair-climbing biomechanics related to the lower extremities when subjects used the novel designed stair-climber, which could provide opportunity for both sagittal and frontal movements. 12 volunteers were required to step while either keeping the trunk static (STATIC) or allowing the trunk to shift with weight bearing (SHIFT). A motion analysis system and the 6-axis force and torque sensor embedded in the pedal were used to collect data. Foot contact forces and joint moments were calculated to represent loading characteristics. The joint angle and corresponding moments at the terminal point of the stance phase were computed to serve as the indicator of safety. Significant differences were found in peak foot contact forces, knee extensor moment, and hip abductor moment. At the end of the stance phase, various directions of moment between conditions were found in the knee and the ankle. The knee valgus angle, hip abductor moment, and knee extensor moment were significantly greater in SHIFT than in STATIC. The various stepping strategies caused differences in joint loading characteristics; therefore, these findings need to be given greater consideration in the design of training protocols.     

Joint loading in the lower extremities during elliptical exercise

PURPOSE: To determine the joint loading during elliptical exercise (EE) by a detailed three-dimensional dynamic analysis, and to compare the results with those during level walking. METHODS: Fifteen male adults performed level walking and EE while 3D kinematic data, right pedal reaction forces (PRF), and ground reaction forces (GRF) were measured. Pedal rate (cadence) and step length during EE without workload were set according to those measured during level walking for each subject. The motion of the body's center of mass, lower-limb-joint angles and moments were obtained. RESULTS: Pedal rates and step lengths were 52.20 rpm (SD=2.34) and 50.56 cm (SD=2.14), respectively. During early stance the vertical PRF was smaller than the GRF, and the medial and posterior shear components were greater. PRF also occurred during swing. Loading rates around heelstrike during EE were all smaller than those during walking. During EE, the peak flexion angles of the hip, knee and ankle were greater. Peak hip flexor and knee extensor moments were also greater, whereas peak ankle plantarflexor moments and all abductor moments were smaller. CONCLUSIONS: Different lower-limb kinematics and kinetics were found between EE and level walking. Smaller vertical PRF and loading rates during EE were achieved at the expense of greater hip flexor and knee extensor moments. Use of the elliptical trainer for athletic and rehabilitative training would have to consider users' joint function and muscle strength, especially at the knee, to avoid injuries.     

Hip and knee frontal plane moments in persons with unilateral, trans-tibial amputation

Persons with unilateral, lower-extremity amputation are at risk of developing osteoarthritis in their intact limb. Among persons without amputation, knee osteoarthritis disease severity has been linked to elevated frontal plane knee moments. Therefore, the purpose of this study was to examine knee and hip frontal plane moments in persons with unilateral, trans-tibial amputation. We hypothesized that knee and hip internal abduction moments are greater in the intact limb compared to the prosthetic side. Three-dimensional gait mechanics were measured bilaterally from 10 persons with unilateral, trans-tibial amputation during walking to calculate lower-extremity joint moments. The intact limb knee and hip peak internal abduction moments were 46% and 39% greater, respectively, than on the prosthetic side. The intact side knee and hip peak internal abduction moments were 17% and 6% greater, respectively, than normal. Larger moments suggest joint loading is of higher magnitude on the intact side, which may be predisposed to premature joint degeneration, particularly knee osteoarthritis.     

Assessment of the effect of a total contact cast on lower limb kinematics and joint loading

BackgroundTotal contact casts (TCCs) are used to immobilize and unload the foot and ankle for the rehabilitation of ankle fractures and for the management of diabetic foot complications. The kinematic restrictions imposed by TCCs to the foot and ankle also change knee and hip kinematics, however, these changes have not been quantified before. High joint loading is associated with discomfort and increased risk for injuries. To assess joint loading, the effect of the muscle forces acting on each joint must also be considered. This challenge can be overcome with the help of musculoskeletal modelling.Research questionHow does a TCC affect lower extremity joint loading?MethodsTwelve healthy participants performed gait trials with and without a TCC. Kinematic and kinetic recordings served as input to subject-specific musculoskeletal models that enabled the computation of joint angles and loading. Cast-leg interaction was modelled by means of reaction forces between a rigid, zero-mass cast segment and the segments of the lower extremity.Resultsand Significance: Reduced ankle, knee and hip range of motion was observed for the TCC condition. Statistical parametric mapping indicated decreased hip abduction and flexion moments during initial contact with the TCC. The anterior knee force was significantly decreased during the mid and terminal stance and the second peak of the compressive knee force was significantly reduced for the TCC. As expected, the TCC resulted in significantly reduced ankle loading.SignificanceThis study is the first to quantify the effect of a TCC on lower limb joint loading. Its results demonstrate the efficiency of a TCC in unloading the ankle joint complex without increasing the peak loads on knee and hip. Future studies should investigate whether the observed knee and hip kinematic and kinetic differences could lead to discomfort.     

Offloading Effects on Impact Forces and Patellofemoral Joint Loading During Running in Females

BackgroundStructure-specific loading is being increasingly recognized as playing a role in running related injuries. The use of interventions targeted at reducing patellofemoral joint loads have shown effectiveness in reducing symptoms of patellofemoral pain. Use of bodyweight support (BWS) has the potential to reduce loading on the patellofemoral joint during running to augment rehabilitation efforts.Research Question:How is patellofemoral joint loading different when using a harness-based BWS system during running?MethodsTwenty-five healthy females free from lower extremity injury were included. Participants completed four running trials on an instrumented treadmill with varying amounts of BWS using a commercially available harness system. Kinematic data from a 3D motion capture system and kinetic data from the treadmill were combined in a computer model to estimate measures of patellofemoral joint loading, knee kinematics, ground reaction force, and stride frequency.ResultsPeak patellofemoral joint stress and time-integral were reduced when running under BWS conditions compared to control conditions. Incremental decreases in patellofemoral loading were not observed with incremental increases in BWS. Peak knee flexion angle was reduced in all BWS conditions compared to control but was not different between BWS conditions. Knee flexion excursion was reduced in only the high BWS condition. Peak ground reaction force and stride frequency incrementally decreased with increased amounts of BWS.SignificanceHarness-based BWS systems may provide a simple means to reduce patellofemoral joint loading to assist in rehabilitation efforts, such as addressing patellofemoral pain.     

Concurrent validity of two-dimensional video analysis of lower-extremity frontal plane of movement during multidirectional single-leg landing

ObjectivesEstablish the concurrent validity between 2D video analysis and 3D motion analysis of frontal plane lower limb movements during multidirectional landing tasks.DesignCorrelation study.SettingUniversity Biomechanics laboratory.Participants34 (19 male, 15 female) uninjured physical active individuals.Main outcome measuresknee abduction and hip adduction angles during a variety of single leg landing tasks.Results2D knee abduction showed an association with 3D knee abduction angle ranging from r = 0.17–0.42 across the tasks, with r² values ranging between 0.03 and 0.17. 2D hip adduction angle in both legs reported a strong and significant correlation with 3D hip adduction angle, ranging from r = 0.70–0.90 across all tasks. Linear regression analysis (r²) revealed that 49–81% of 3D hip adduction angle can be explained by 2D measurement.ConclusionIt might be difficult to explain 3D knee abduction angle using 2D video analysis during single leg landing tasks, whereas 2D hip adduction angle is a strong predictor or 3D hip adduction angle. It would appear 2D video analysis has strong concurrent validity when assessing hip adduction angle, but it is weak when assessing knee abduction angle during a variety of single leg landing tasks.     

Heel height affects lower extremity frontal plane joint moments during walking

Wearing high heels alters walking kinematics and kinetics and can create potentially adverse effects on the body. Our purpose was to determine how heel height affects frontal plane joint moments at the hip, knee, and ankle, with a specific focus on the knee moment due to its importance in joint loading and knee osteoarthritis. 15 women completed overground walking using three different heel heights (1, 5, and 9 cm) for fixed speed (1.3 ms(-1)) and preferred speed conditions while kinematic and force platform data were collected concurrently. For both fixed and preferred speeds, peak internal knee abduction moment increased systematically as heel height increased (fixed: 0.46, 0.48, 0.55 N m kg(-1); preferred: 0.47, 0.49, 0.53 N m kg(-1)). Heel height effects on net frontal plane moments of the hip and ankle were similar to those for the knee; peak joint moments increased as heel height increased. The higher peak internal knee abduction moment with increasing heel height suggests greater medial loading at the knee. Kinetic changes at the ankle with increasing heel height may also contribute to larger medial loads at the knee. Overall, wearing high heels, particularly those with higher heel heights, may put individuals at greater risk for joint degeneration and developing medial compartment knee osteoarthritis.     

Impact of fatigue on gender-based high-risk landing strategies

PURPOSE: Noncontact anterior cruciate ligament (ACL) injuries carry significant short- and long-term morbidity, particularly in females. To combat this epidemic, neuromuscular training has evolved aimed at modifying high-risk lower-limb biomechanics. However, injury rates and the gender disparity in these rates remain, suggesting that key components of the injury mechanism continue to be ignored. This study examined the potential contributions of neuromuscular fatigue to noncontact ACL injuries. METHODS: Ten male and 10 female NCAA athletes had 3D lower-limb-joint kinematics and kinetics recorded during 10 drop jumps, both before and after fatigue. Mean subject-based initial-contact (N = 9) and peak stance-phase kinematic (N = 9) and normalized (mass x height) kinetic (N = 9) parameters were quantified before and after fatigue and submitted to a three-way ANOVA to determine for the main effects of leg, gender, and fatigue. A Bonferroni corrected alpha level of 0.002 was adopted for all statistical comparisons. RESULTS: Females landed with more initial ankle plantar flexion and peak-stance ankle supination, knee abduction, and knee internal rotation compared with men. They also had larger knee adduction, abduction, and internal rotation, and smaller ankle dorsiflexion moments. Fatigue increased initial and peak knee abduction and internal rotation motions and peak knee internal rotation, adduction, and abduction moments, with the latter being more pronounced in females. CONCLUSIONS: Fatigue-induced modifications in lower-limb control may increase the risk of noncontact ACL injury during landings. Gender dimorphic abduction loading in the presence of fatigue also may explain the increased injury risk in women. Understanding fatigue effects at both the central and peripheral levels will further afford elucidation of the ACL injury mechanism and, hence, more successful prevention strategies.     

Dynamic loading of the knee and hip joint and compensatory strategies in children and adolescents with varus malalignment

Three-dimensional gait analysis is a diagnostic tool that can be used to gain a better understanding of the relationship between joint loading and the onset or progression of articular cartilage degeneration in subjects with varus malalignment. The purpose of the present study was to investigate knee and hip joint angles and moments in children and adolescents with pathological varus alignment of the knee without signs of knee osteoarthritis (OA). Moreover, we wanted to know if compensatory mechanisms are present in this young patient group. Fourteen, otherwise healthy patients with varus malalignment of the knee and 15 healthy control subjects were analysed. Patients showed a reduced knee extension and a significantly lower maximum knee extension moment in terminal stance compared to controls. The maximum knee adduction moment in mid and terminal stance and the maximum hip abduction moment in loading response were significantly higher in the patient group. In the transverse plane, abnormally increased knee internal rotation and hip external rotation moments were present in patients with varus malalignment. These findings imply that varus malalignment is not an isolated problem in the frontal plane. In contrast to adult patients with established medial knee OA, the young patients assessed in the present study did not show typical compensatory mechanisms such as increased foot progression angle or reduced walking speed. This suggests that children and adolescents with varus malalignment of the knee probably do not need to alter their spatio-temporal gait parameters in order to decrease knee joint loading.     

Effect of external marker sets on between-day reproducibility of knee kinematics and kinetics in stair climbing and level walking

The purpose of this study was to compare the between-day repeatability of the knee kinematics and kinetics in stair climbing and level walking among three marker sets: the Helen-Hays marker set with some markers on well-defined bony landmarks and some on not well-defined locations on soft tissues, the modified Helen-Hays marker set with a static calibration trial, and the UNC-CH marker set with all marker on well defined bony landmarks and a static calibration trial. Three-dimensional coordinates of markers in stair climbing and level walking were collected for six subjects on three days. Three-dimensional knee joint angles and resultant forces and moments were calculated. A between-day coefficient of multiple correlation was used to represent between-day repeatability of the knee joint angles, and resultant forces and moments during the stance phases of the stair climbing and level walking. Marker set had significant effect on the knee joint angles and resultant forces and moments (p < 0.02), except the knee axial force. The modified Helen-Hays marker set with a static calibration significantly improved the between-day repeatability for most of the knee angles and resultant forces and moments. The UNC-CH marker set with all markers on well-defined bony landmarks and a static calibration trial further improved the between-day repeatability of most the knee angles and resultant forces and moments.     

Effect of External Marker Sets on Between-Day Reproducibility of Knee Kinematics and Kinetics in Stair Climbing and Level Walking

The purpose of this study was to compare the between-day repeatability of the knee kinematics and kinetics in stair climbing and level walking among three marker sets: the Helen-Hays marker set with some markers on well-defined bony landmarks and some on not well-defined locations on soft tissues, the modified Helen-Hays marker set with a static calibration trial, and the UNC-CH marker set with all marker on well defined bony landmarks and a static calibration trial. Three-dimensional coordinates of markers in stair climbing and level walking were collected for six subjects on three days. Three-dimensional knee joint angles and resultant forces and moments were calculated. A between-day coefficient of multiple correlation was used to represent between-day repeatability of the knee joint angles, and resultant forces and moments during the stance phases of the stair climbing and level walking. Marker set had significant effect on the knee joint angles and resultant forces and moments (p < 0.02), except the knee axial force. The modified Helen-Hays marker set with a static calibration significantly improved the between-day repeatability for most of the knee angles and resultant forces and moments. The UNC-CH marker set with all markers on well-defined bony landmarks and a static calibration trial further improved the between-day repeatability of most the knee angles and resultant forces and moments.     

Effect of prosthetic alignment on gait and biomechanical loading in individuals with transfemoral amputation: A preliminary study

BackgroundInappropriate biomechanical loading usually leads to a high incidence of hip and knee osteoarthritis (OA) in individuals with lower-limb amputation, and prosthetic alignment may be an important influencing factor. The effect of alignment on the lower limb loading remains quantitatively unclear, and the relationship between malalignment and joint diseases is undefined.Research questionHow does alignment affect spatiotemporal gait parameters and ground reaction force (GRF) in individuals with transfemoral amputation?MethodsGait tests of 10 individuals with transfemoral amputation were performed with recommended alignment and eight malalignments, including 10 mm socket translation (anterior, posterior, medial, and lateral) and 6° socket angular changes (flexion, extension, abduction, and adduction). Fifteen individuals without amputation were recruited as a control group. The differences in spatiotemporal and GRF parameters under different alignments were analyzed and compared with those of the control group. Statistical analyses were performed by one-way ANOVA, repeated measure multivariate ANOVA, and paired t tests.ResultsThe medial GRF peaks and impulse on both sides and load rate on the intact side are significantly higher than those of the control group (P < 0.0056). The propulsive and braking peaks, vertical impulse, and medial and vertical load rates of GRF on the intact side are higher than those on the residual side (P < 0.05). The alignment of socket adduction significantly increases medial GRF peak and impulse on both sides (P < 0.0056).SignificanceAlignments exert remarkable and complicated effects on the biomechanical performance. The considerably higher GRF on the intact side of the individuals with transfemoral amputation may lead to internal stress changes of the intact joint, which may be an inducement for high incidence of joint diseases. Probably due to the increased lateral deviation of the center of gravity, the socket adduction alignment significantly increases medial GRF, which may lead to an increased risk of knee OA.     

Reliability and validity of the Kinect V2 for the assessment of lower extremity rehabilitation exercises

BackgroundBesides its initial use as a video gaming system the Kinect might also be suitable to capture human movements in the clinical context. However, the system’s reliability and validity to capture rehabilitation exercises is unclear.Research questionThe purpose of this study was to evaluate the test-retest reliability of lower extremity kinematics during squat, hip abduction and lunge exercises captured by the Kinect and to evaluate the agreement to a reference 3D camera-based motion system.MethodsTwenty-one healthy individuals performed five repetitions of each lower limb exercise on two different days. Movements were simultaneously assessed by the Kinect and the reference 3D motion system. Joint angles and positions of the lower limb were calculated for sagittal and frontal plane. For the inter-session reliability and the agreement between the two systems standard error of measurement (SEM), bias with limits of agreement (LoA) and Pearson Correlation Coefficient (r) were calculated.ResultsParameters indicated varying reliability for the assessed joint angles and positions and decreasing reliability with increasing task complexity. Across all exercises, measurement deviations were shown especially for small movement amplitudes. Variability was acceptable for joint angles and positions during the squat, partially acceptable during the hip abduction and predominately inacceptable during the lunge. The agreement between systems was characterized by systematic errors. Overestimations by the Kinect were apparent for hip flexion during the squat and hip abduction/adduction during the hip abduction exercise as well as for the knee positions during the lunge. Knee and hip flexion during hip abduction and lunge were underestimated by the Kinect.SignificanceThe Kinect system can reliably assess lower limb joint angles and positions during simple exercises. The validity of the system is however restricted. An application in the field of early orthopedic rehabilitation without further development of post-processing techniques seems so far limited.     

The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus

BackgroundPes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required.Research questionThe aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus.Methodskinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle.ResultsThe results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037).SignificanceFOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments.     

Knee contact forces are not altered in early knee osteoarthritis

ObjectiveThis study calculated knee contact forces (KCF) and its relations with knee external knee adduction moments (KAM) and/or flexion moments (KFM) during the stance phase of gait in patients with early osteoarthritis (OA), classified based on early joint degeneration on Magnetic Resonance Imaging (MRI). We aimed at assessing if altered KCF are already present in early structural degeneration.DesignThree-dimensional motion and ground reaction force data in 59 subjects with medial compartment knee OA (N = 23 established OA, N = 16 early OA, N = 20 controls) were used as input for a musculoskeletal model. KAM and KFM, and KCF were estimated using OpenSim software.ResultsNo significant differences were found between controls and subjects with early OA. In early OA patients, KAM significantly explained 69% of the variance associated with the first peaks KCF but only KFM contributed to the second peaks KCF. The multiple correlation, combining KAM and KFM, showed to be higher. However, only 20% of the variance of second peak KCF was explained by both moments in established OA.ConclusionKCF are not increased in patients with early OA, suggesting that knee joint overload is more a consequence of further joint degeneration in more advanced stages of OA. Additionally, our results clearly show that KAM is not sufficient to predict joint loading at the end of the stance, where KFM contributes substantially to the loading, especially in early OA.     

Influence of lower extremity rotation on knee kinematics in single-leg landing

ObjectivesAlthough the rotation of lower extremities has gained increasing recognition as a risk factor for anterior cruciate ligament (ACL) injury. This study clarified the influence of lower extremity rotation on the knee during single-leg landing. Design and Setting: We recruited 30 students to perform single-leg landing from a height of 30 cm with their lower extremities in neutral, and externally and internally rotated. The knee abduction, flexion angles, and abduction angular velocity were measured. Furthermore, the abduction angle was analyzed at knee flexion angles of 15°, 20°, 25°, and 30° and compared among the three conditions using a repeated measures analysis of variance with Bonferroni post hoc tests.ResultsThe maximum abduction angle was significantly greater when internally rotated than in the neutral. The maximum abduction angular velocity was significantly greater in the internally rotated compared to in the neutral. Finally, the abduction angle at a knee flexion angle of 30° was significantly greater when internally rotated compared to in the neutral.ConclusionRotation of the lower extremities affects knee kinematics, and landing on a knee that is internally rotated may increase the risk of ACL injury.     

The immediate effects of Kinesio Taping on running biomechanics,muscle activity,and perceived changes in comfort,stability and running performance in healthy runners,and the implications to the management of Iliotibial band syndrome

BackgroundKinesio Taping is frequently used in the management of lower limb injuries, and has been shown to improve pain, function, and running performance. However, little is known about the effects of Kinesio Taping on running biomechanics, muscle activity, and perceived benefits.Research questionThis study aimed to explore the immediate effects of Kinesio Taping on lower limb kinematics, joint moments, and muscle activity, as well as perceived comfort, knee joint stability, and running performance in healthy runners.MethodsTwenty healthy participants ran at a self-selected pace along a 20-metre runway under three conditions; no tape (NT), Kinesio Tape with tension (KTT), and Kinesio tape without tension (KTNT). Comparisons of peak hip, knee angles and moments, and EMG were analysed during the stance phase of running.ResultsKTT exhibited significant increases in peak hip flexion, peak hip abduction and hip external rotation compared to NT. Moreover, the KTT condition showed a trend towards a decrease in peak hip internal rotation and adduction angle compared to the NT condition. EMG results showed that Tensor Fascia Latae activity decreased with KTT compared with NT, and Gluteus Maximus activity reduced with KTNT when compared with NT. Ten of the 20 participants indicated important improvements in the comfort score, six participants in the knee stability score, and seven participants in the running performance score when using KTT.SignificanceThese results suggest that changes in running biomechanics previously associated with ITBS can be improved with the application of kinesio tape, with the greatest effect seen with the application of kinesio tape with tension. Perceived improvements were seen in comfort, stability and running performance, however these benefits were only seen in half the participants. Further work is required to explore the biomechanical effects and perceived benefits in different patient groups.