Forward Lunge Research Articles

The impact of anterior knee displacement on knee joint load during the forward bow step in Tai Chi.

While the forward bow step is a crucial component of Tai Chi (TC) practice, little research has been conducted on its impact on knee joint load and muscle coordination. This study aims to investigate the effects of three different knee forward positions during the TC forward bow step on knee joint loading. Twenty TC practitioners were recruited, and motion capture systems, force platforms, and surface electromyography were utilized to synchronously collect biomechanical parameters of three types of forward bow steps: knee joint not exceeding the tip of the foot (NETT), knee joint forward movement level with the tip of the foot (LTT), and knee joint forward movement exceeding the tip of the foot (ETT). Ligament and muscle forces were calculated using OpenSim software for musculoskeletal modeling and simulation. One-way ANOVA was used to analyze the variations of the indicators during the peak anterior displacement of the knee joint in three movements. Additionally, spm1d one-way ANOVA was employed to examine the variations in the one-dimensional curve of the indicators throughout the entire movement process. Compared with LTT and ETT, the NETT posture was associated with significantly decreased knee flexion angle (F = 27.445, p = 0.001), knee anterior-posterior translation (F = 36.07, p < 0.001), flexion-extension torque (F = 22.232, p = 0.001), ligament force (F = 9.055, p = 0.011). Additionally, there was also a significant reduction in muscle strength, including quadriceps (F = 62.9, p < 0.001), long biceps femoris (F = 18.631, p = 0.002), lateral gastrocnemius (F = 24.933, p = 0.001) and soleus (F = 7.637, p = 0.017). This study further confirms that in the forward lunge movement of Tai Chi, the knee joint load is mainly concentrated during the forward movement phase. Compared to the knee joint load at the NETT position, the load is greater at the LTT position; and compared to the LTT position, the load is even greater at the ETT position.

Cubicle design and dairy cow rising and lying down behaviours in free-stalls with insufficient lunge space

Cubicle partitions divide the resting area of free-stalls into individual lying places for cows, thereby facilitating the maintenance of good hygiene and reducing competition by separating animals. The forward lunge space in lying cubicles is often insufficient for a natural head lunge movement during rising. Cubicles with open frame partitions and a flexible neck strap aim to alleviate this welfare issue. The open partition frame facilitates lateral space sharing (using space of neighbouring cubicles for the head lunge movement) and the flexible neck strap is presumably less painful upon collision. In an observational study, we investigated the lying behaviour of free-stall housed dairy cows in this ’permissive’ cubicle type with open frame partitions and a flexible neck strap positioned relatively high above the lying surface compared to ’restrictive’ cubicles with partitions with more bar work in the lateral lunge space and a lower-positioned rigid neck rail. The study was conducted on commercial Swiss dairy farms with exclusively wall-facing lying cubicles of either the permissive (four farms) or restrictive (six farms) type. The forward lunge space on these farms ranged from 55 to 70 cm, which we considered insufficient for adult cows to lunge their heads forward. On each farm, 18–20 lactating dairy cows were selected. In total, 188 animals were used in the statistical analysis. Over 1.5 days, rising and lying down movements were videotaped, and the prevalence of atypical behaviours during these movements was recorded. In addition, we determined the daily lying duration, the lying frequency, and the mean lying bout duration using accelerometers mounted on the left hind leg. The data was analysed in relation to the cubicle type (permissive or restrictive). In the permissive cubicle type, staggered head lunge movements during rising and displays of hesitance before lying down were less prevalent. The lying frequency was higher, and daily lying duration was longer in the permissive cubicle type, although these estimates should be interpreted with caution due to the short data collection period. The results of this study suggest that the permissive cubicle with open partitions and a high-positioned flexible neck strap may improve conditions for dairy cows to rise and lie down. A permissive cubicle design may therefore improve cow welfare in free-stalls with insufficient forward lunge space, where increasing lunge space is not feasible.

The influence of unstable surfaces on ankle muscle activation during functional exercises

BackgroundThe study aims to compare how 3 balance platform designs affect ankle muscle activation during various functional exercises, all performed on the dominant limb. MethodsFifteen healthy, active participants performed single-leg stance, single-leg squat, and forward lunge on BOSU® Ball, wobble board, stability trainer, and flat ground. Surface electromyography was used to measure Peroneus Longus, Tibialis Anterior, Gastrocnemius, and Soleus activation during these exercises on different platforms and flat ground. Repeated measures ANOVA with two factors (exercise and platform) were used for analysis. ResultsThere was a significant interaction between balance platforms and exercises (p < 0.05). Soleus displayed the highest activation amplitudes during the single leg stance and single leg squat on BOSU®, and peroneus longus displayed the greatest activation amplitudes during the forward lunge on BOSU® (p < 0.05). ConclusionsThe present study findings indicated that exercises conducted on a flexible platform resulted in greater muscle activation levels when compared to those executed on both a rigid platform and flat ground. Based on the level of ankle muscle activation in the current study, exercises for the ankle would progress from exercises on to a flat ground to on a BOSU® in order to achieve progressively greater ankle muscle activation. Level of evidenceLevel III.

Residual Effects of Same Day Lower Extremity Strength Training on Countermovement Jump Performance in Collegiate Women Athletes.

Balancing of strength programming intensity with sport demands is necessary to avoid excessive workloads that could inhibit performance. To expand previous jump height focused literature, this study evaluated whether countermovement jump (CMJ) movement strategies, including eccentric characteristics, might reveal CMJ execution strategy shifts to achieve similar afternoon CMJ height following a morning resistance training session (RTS). Fifteen collegiate women's soccer and volleyball athletes (18-24 years, 73.6 ± 8.4 kg, 1.74 ± 0.19 m) participating in an offseason RTS completed five CMJs during two afternoon sessions (48 h apart), one 4-6 h post morning RTS, and one on a rest day. The RTS consisted of 2 sets of 10 repetitions at 70-80% 1RM for the back squat, the front squat, and the forward lunge. Vertical ground reaction forces were recorded from which 13 outcome measures describing elements of the eccentric and concentric CMJ phases were computed. No significant differences in jump height (p = 0.427, d = 0.17) or outcome measures (p = 0.091-0.777, d = -0.07-0.21) between sessions with exception of a significant concentric phase time decrease (p = 0.026, d = 0.23) following the RTS were identified. Given the magnitude of the mean concentric phase time change (0.01 s), the result likely has limited practical meaning. As these results confirm previous CMJ height literature, practitioners have further evidence that a morning RTS does not interfere or enhance afternoon CMJ performance in athletic women.

Two Repetitions May Be Enough! Reliability of Movement Timing in Physical Fitness Exercises Performed by Young, Trained Adults Using Inertial Sensors

This study aimed to determine the minimum number of repetitions for a high reliability of movement timing in fundamental physical fitness exercises using inertial sensors. Fifteen young men and fifteen women performed eight exercises (two-leg hop, forward lunge, squat, sit-up, shoulder abduction, hip abduction, back extension, and push-up) (preferred tempo, 3 trials, 20 repetitions per trial). The movement timing (cycle of movement in seconds and its phases in seconds and %tcycle) was tested for intra- and inter-trial reliability (SPSS 28.0, p ≤ 0.05). Just two repetitions were adequate for excellent intra- and inter-trial relative reliability (ICCs ≥ 0.75, isolated exceptions only for durations expressed as %tcycle, in only three out of the eight exercises: hip abduction, back extension, and push-up), as well as for high absolute intra- and inter-trial reliability (average SEM% at 5.9%, respectively, and 6.8% and average MDC95% at 13.7% and 15.9%, respectively, which was consistently higher than the upper boundary limit of SEM%, and a rather low CV% ranging from 1.5% to 4.9% and averaging at 3.1%). A total of four repetitions, excluding the initial and the final one, appears adequate for high overall reliability of movement timing in the eight physical fitness exercises examined.

Reverse Nordic Curl Does Not Generate Superior Eccentric Activation of the Quadriceps Muscle Than Bodyweight Squat-Based Exercises.

The quadriceps femoris is consistently ranked among the muscles most prone to sustain strain injuries in sports involving kicking and sprinting actions. Given the documented preventive effect of Nordic hamstring curl programs against hamstring strain injuries, incorporating exercises that induce eccentric overload on the quadriceps could potentially help mitigate strain injuries within this muscle group. The Reverse Nordic Curl (RNC) has emerged as a viable field-based exercise for eccentrically working the quadriceps. This study aimed to compare quadriceps muscle eccentric activation during the RNC with 3 bodyweight squat-based exercises: single-leg squat (SLS), Bulgarian squat, and forward lunge. Cross-sectional study. Twenty-three healthy volunteers (15 men) were monitored for rectus femoris, vastus lateralis, and vastus medialis electromyographic signal, as well as knee range of motion, while performing 10 repetitions of each exercise. Electromyography data acquired during eccentric phases were normalized by maximum voluntary isometric contraction of the knee extensors. The exercises were compared based on the electromyography and knee range of motion values. RNC generated a similar rectus femoris and vastus medialis eccentric activation compared with the squat-based exercises (P > .05 for all), and a lower vastus lateralis activation than SLS (P < .001). Among the bodyweight squat-based exercises, SLS generated greater eccentric activation than forward lunge and Bulgarian squat for the 3 muscles (P < .05 for all). RNC was performed with lower knee-flexion range of motion than bodyweight squat-based exercises (P < .001). RNC did not produce superior eccentric quadriceps activation compared to bodyweight squat-based exercises, even proving to be less demanding for the vastus lateralis compared to the SLS. These findings may assist practitioners in selecting exercises to elicit quadriceps eccentric stimulus, with a focus on preventing strain injuries.

Comparison of ground reaction force and contact time during various-direction lunges between badminton shoes without and with a lateral forefoot wedge sole

This study compared the ground reaction force (GRF), GRF ratio, and contact time between badminton shoes without and with a lateral forefoot wedge sole during lunges in three directions. Fifteen collegiate athletes wore forefoot wedge shoes (5° incline) and control shoes without a lateral forefoot wedge sole (in random order) and performed three typical badminton lunge movements (forward, lateral, and backward directions). A total of nine GRF, GRF ratio, and contact time parameters were analyzed. A paired t test was performed to assess the differences between two shoes. The significance level was set at p &lt; 0.0056 (0.05/9) based on Bonferroni correction to avoid chances of type 1 errors. In the forward lunge, the forefoot wedge shoes resulted in a significantly higher average vertical ground reaction force (GRFv, 3.9%), average horizontal GRF (GRFh, 7.8%) in the braking phase and higher average GRFh (3.9%) in the propulsion phase than the control shoes. In the lateral lunge, the forefoot wedge shoes resulted in a significantly shorter total contact time (−4.6%) than the control shoes in the backward lunge, the forefoot wedge shoes resulted in a significantly higher GRFh to GRFv ratio (6.4%) in the braking phase compared with the control shoes. Thus, shoes with a lateral forefoot wedge sole can effectively enhance mechanical performance in direction changes during forward and backward badminton lunges, and shorter the contact time during lateral badminton lunges. Shoes with a lateral forefoot wedge sole can be considered when designing athletic footwear.

External weight mass and carrying position influence peak patellar tendon force and patellofemoral joint contact force independently during forward lunge

BackgroundThe forward lunge is a common exercise in the rehabilitation of patellar tendinopathy and patellofemoral pain syndrome. External weights are frequently used to increase the peak patellar tendon force and patellofemoral joint contact force during this exercise. The weight's position might influence this relationship. The objective of this study was to investigate the combined effect of an external weight's mass and carrying position on the peak patellar tendon force and patellofemoral joint contact force during a forward lunge. MethodsTen healthy individuals performed forward lunges holding external weights between 0.1 and 0.3 times body mass either in one hand at the ipsilateral or contralateral side of the leading leg, or in two hands at the side or in front of the trunk. Three-dimensional kinematic data and ground reaction forces were collected and peak patellar tendon force and patellofemoral joint contact force were calculated using musculoskeletal modelling. Two-way repeated measures ANOVA's determined the main effects for the external weight's mass and position as well as their interaction effect. FindingsIncreasing the mass of the external weights increased both the peak patellar tendon force and patellofemoral joint contact force linearly and at the same rate in all positions. Both peak forces were larger in the one-hand ipsilateral and two-hand side positions. InterpretationAn external weight's mass and position both influence the peak patellar tendon force and patellofemoral joint contact force during a forward lunge. The rate of increase in peak forces with increasing mass was similar for all weight-carrying positions.

Preliminary data of kinematics and kinetics of forward lunge in exercise-proficient individuals: Does dominant vs. non-dominant leg matter?

Preliminary data of kinematics and kinetics of forward lunge in exercise-proficient individuals: Does dominant vs. non-dominant leg matter?

Quadriceps and gluteus medius activity during stable and unstable loading exercises in athletes. A cross-sectional study.

The aim of this study was to evaluate the muscle activation of the vastus medialis, vastus lateralis, and gluteus medius during different strength and stability exercises with a water tank compared with a sandbag. A cross-sectional study was conducted in the Functional Anatomy Laboratory, and the sample consisted of 28 athletes. The main outcome measures were surface electromyography (dependent variable), water tank and sandbag, and exercise type (independent variables): Isometric Single Leg Stance (ISLS), One Leg Deadlift (OLDL), Front Rack Forward Lunge (FRFL), and Lateral Lunge (LL). Repeated measures analysis of variance (ANOVA) revealed a significant Group × Time interaction in gluteus medius root mean square (RMS) (F = 14.198, p < 0.001, ŋ2 = 0.35), vastus lateralis RMS (F = 24.374, p < 0.001, ŋ2 = 0.47), and vastus medialis RMS (F = 27.261, p < 0.001, ŋ2 = 0.50). In the between-group analysis, statistically significant differences were observed in gluteus medius RMS in the ISLS: 28.5 ± 15.8 water tank and 20.8 ± 12.6 sandbag (p < 0.001, ŋ2 = 0.08) and OLDL: 29.7 ± 13.3 water tank and 26.5 ± 13.1 sandbag (p < 0.001, ŋ2 = 0.01). In vastus lateralis in ISLS: 30.4 ± 37.6 water tank and 19.0 ± 26.7 sandbag (p < 0.001, ŋ2 = 0.03). In vastus medialis in ISLS: 14.2 ± 13.0 water tank and 7.0 ± 5.6 sandbag (p < 0.001, ŋ2 = 0.12), OLDL: 21.5 ± 16.9 water tank and 15.5 ± 10.7 sandbag (p = 0.002, ŋ2 = 0.04), and LL: 51.8 ± 29.6 water tank and 54.3 ± 29.3 sandbag (p = 0.017, ŋ2 = 0.00). These results confirm significantly greater activation of the gluteus medius and vastus medialis in the ISLS and OLDL exercises, and of the vastus lateralis in the water tank ISLS exercise. However, the vastus medialis shows greater activation in the LL exercise.

Biomechanical effects of exercise fatigue on the lower limbs of men during the forward lunge.

Background: During competition and training, exercises involving the lungs may occur throughout the sport, and fatigue is a major injury risk factor in sport, before and after fatigue studies of changes in the lungs are relatively sparse. This study is to investigate into how fatigue affects the lower limb's biomechanics during a forward lunge. Methods: 15 healthy young men participate in this study before and after to exposed to a fatigue protocol then we tested the forward lunge to obtain kinematic, kinetic changing during the task, and to estimate the corresponding muscles' strength changes in the hip, knee, and ankle joints. The measurement data before and after the fatigue protocol were compared with paired samples t-test. Results: In the sagittal and horizontal planes of the hip and knee joints, in both, the peak angles and joint range of motion (ROM) increased, whereas the moments in the sagittal plane of the knee joint smaller. The ankle joint's maximum angle smaller after fatigue. Peak vertical ground reaction force (vGRF) and peak contact both significantly smaller after completing the fatigue protocol and the quadriceps mean and maximum muscular strength significantly increased. Conclusion: After completing a fatigue protocol during lunge the hip, knee, and ankle joints become less stable in both sagittal and horizontal planes, hip and knee range of motion becomes greater. The quadriceps muscles are more susceptible to fatigue and reduced muscle force. Trainers should focus more on the thigh muscle groups.

The Effects of a Forward Lunge with Hip Adduction on Muscle Activity and Plantar Pressure in Healthy Subjects

The Effects of a Forward Lunge with Hip Adduction on Muscle Activity and Plantar Pressure in Healthy Subjects

The effects of ankle dorsiflexor fatigue on lower limb biomechanics during badminton forward forehand and backhand lunge.

Background: Local muscle fatigue may have an adverse effect on the biomechanics of the lunge movement and athletic performance. This study analyzed the biomechanical indicators of the forward lunge in badminton players before and after fatigue of the ankle dorsiflexors. Methods: Using the isometric muscular strength testing system, 15 badminton players underwent an ankle dorsiflexor fatigue test. Before and after the fatigue experiment, five lunges were done in both the forehand forward (FH) and backhand forward (BH) directions, five in each direction. A Vicon motion capture system and an AMTI force measuring station were used to record lower limb kinematic and ground reaction force (GRF). Pre-fatigue and post-fatigue variability were determined using paired-samples t-tests, Wilcoxon signed rank test, and Statistical Non-parametric Mapping (SNPM). Result: The results showed that after fatigue, the peak angle of ankle dorsiflexion was significantly reduced (p = 0.034), the range of motion (ROM) of the ankle sagittal plane (p = 0.000) and peak angle of ankle plantarflexion (p = 0.001) was significantly increased after forehand landing. After fatigue, ankle inversion was significantly increased after forehand and backhand landings (FH: p = 0.033; BH: p = 0.015). After fatigue, peak knee flexion angles increased significantly (FH: Max: p = 0.000, Min: p = 0.000; BH: Max: p = 0.017, Min: p = 0.037) during forehand and backhand landings and ROM in knee flexion and extension increased (p = 0.009) during forehand landings. Knee inversion range of motion was significantly increased after fatigue (p = 0.024) during forehand landings. Peak hip flexion angle (p = 0.000) and range of motion (p = 0.000) were significantly reduced in forehand landings after fatigue. The mean loading rate (p = 0.005) and the maximum loading rate (p = 0.001) increased significantly during backhand landings after fatigue. Post-fatigue, the center of pressure (COP) frontal offset increased significantly (FH: p = 0.000; BH: p = 0.000) in the forehand and backhand landings. Conclusion: These results indicate that when the ankle dorsiflexors are fatigued, the performance of the forehand is significantly negatively affected, and the impact force of the backhand is greater.

Peroneal muscle activity during stable and unstable load exercises. A cross-sectional study

ObjectiveTo evaluate the muscle activity of the peroneus longus during the execution of different unstable load exercises compared to stable load exercises. DesignCross-sectional study. SettingFunctional Anatomy Laboratory. Participants28 healthy athletes. Main outcome measuresSurface electromyography (sEMG), unstable load (water tank), Stable Load (Sandbag), type of exercise (Isometric single leg stance, single-leg Romanian deadlift, front rack forward lunge and lateral lunge). ResultsThe repeated measures ANOVA revealed significant Group ∗ Time interaction in Root Mean Square (RMS) (F = 51.307, P < 0.001, ŋ2 = 0.70). In the between-group analysis there were statistically significant differences in RMS isometric single leg stance in favor to unstable load (P < 0.001, ŋ2 = 0.07). In the within-group analysis of RMS statistically significant differences were found in the stable load group between isometric single leg stance and single-leg Romanian deadlift (P < 0.001, ŋ2 = 0.05). ConclusionsSingle leg stance exercise with unstable load showed higher peroneus muscle activity than stable load. However, no peroneus muscle activity differences were found between unstable and stable loads for single-leg Romanian deadlift, frontal rack forward lunge and lateral lunge. Single-leg Romanian deadlift with stable load showed higher peroneus muscle activity than isometric single leg stance with stable load.

ANALISIS BIOMEKANIK KINETIK PADA ATLET BADMINTON DENGAN NYERI LUTUT SAAT GERAKAN BACKHAND DIAGONAL FORWARD LUNGES

AbstractBadminton is a popular racquet sport around the world, this sport has the characteristics of explosive and intensive movements. The incidence of badminton injuries less than the other sports, but the severity is higher, one of the most common injuries is knee injury The purpose of this study was to see there was a relationship or not between the quality of knee pain (measured by KOOS), muscle activation (measured by surface EMG) and to determine whether there is an effect of multiregional history injury on the activation of m.vastus medialis oblique, m.vastus lateralis, m.biceps femoris and m.erector spine during backhand diagonal forward lunges. This type of research is a cross sectional study design The samples in this study were 21 athletes who were included in the inclusion criteria. The results of the normality test were by Shapiro Wilk the results obtained were p 0.064&gt; 0.05, the correlation test using Pearson correalation 0.00 &lt;00.5 there is a strong relationship between the quality of pain with muscle activation and different tests using the independent sample t-test m.erector spine (0.04 &lt;0.05) showed an effect of multiregional injury history on activation on m.erector spine. Keywords: Badminton, Lunges, Knee Pain, Muscle activation

Weight-Bearing Exercises on Slideboard Increase Quadriceps and Hamstring Activation Levels and Improve Hip- and Knee-Flexion Angles in Physically Active Individuals.

Slideboards are commonly used in exercise programs, but there is limited information about how they affect muscle activities during exercise. We aim to compare the activation levels of quadriceps and hamstring muscles and hip- and knee-flexion angles during lunge and single-leg squat exercises between normal ground and slideboard in physically active individuals. Cross-sectional study. Thirty healthy individuals (age: 23.83 [2.84]y, body mass index: 21.75 [1.72]kg/m2) were included in the study. Surface electromyography was used to measure vastus medialis, vastus lateralis, biceps femoris, and semitendinosus activation levels during reaching and returning phases of the forward, lateral, and back lunges and squats that were performed on the normal ground and slideboard. Exercises were performed at a slow pace (60 beats/min). Hip- and knee-flexion angles during the exercises were evaluated by using 2-dimensional motion analysis. Repeated measures of analysis of variance were used for statistical analysis. Vastus medialis and vastus lateralis activation levels were greater during reaching and returning phases of the exercises on slideboard compared with normal ground (P < .05). However, semitendinosus and biceps femoris activity were greater only during the returning phase of the forward lunge (P < .001) and the returning phase of the back squat (P = .002, P = .009, respectively). Hip-to-knee flexion ratios were closer to 1 when the forward lunge (P < .001), back lunge (P = .004), and forward squat (P = .001) exercises were performed on a slideboard. In exercise programs that target the quadriceps and hamstring muscles, slideboards can be effectively used in exercise progressions as they can increase muscle activity. Moreover, squat and lunge exercises on slideboard with a slow pace may also be helpful for improving the balance between hip- and knee-flexion angles.

Biomechanical demands of exercises commonly performed by older adults in falls prevention programs

BackgroundTailored, challenging and progressed exercise programs addressing risk factors are recommended for preventing falls in community-dwelling older adults. Knowing the biomechanical demands of exercises commonly performed in efficacious falls prevention programs provides evidence for exercise prescription. MethodsTwenty-one non-sedentary older adults (10 men, 11 women, mean age 69 [SD 5] years) performed five standing exercises (hip abduction, side-step, squat, forward lunge, and side lunge). A biomechanical analysis of the dominant limb was performed to calculate peak joint angles and net joint moments at the ankle, knee and hip in multiple planes. Repeated-measures one-way analyses of variance followed by post-hoc comparisons were performed to identify differences in the calculated variables between exercises. FindingsPeak hip abduction moments during hip abduction were greater than during the forward lunge and squat (P < 0.001). During the side-step, peak plantar flexion moments were greater than the squat and peak hip abduction moments were greater than the squat and forward lunge (P < 0.001). During the squat, peak hip flexion was greatest (P < 0.001) while peak plantar flexion (P < 0.001) and hip abduction moments (P ≤ 0.002) were less than all other exercises. During the forward lunge, peak hip extension moments (P < 0.001) were greatest. During the side lunge, peak knee extension moments were greater than all other exercises (P < 0.001). InterpretationThese biomechanical data will allow clinicians to tailor exercises for falls prevention to efficiently challenge but not overload muscle groups and minimize exercise prescription redundancies.

Altered movement strategy during functional movement after an ACL injury, despite ACL reconstruction.

Knee joint functional deficits are common after anterior cruciate ligament (ACL) injury, but different assessment methods of joint function seem to provide contradicting information complicating recovery monitoring. We previously reported improved perceived knee function and functional performance (forward lunge ground contact time) in patients with an ACL injury from pre to 10 months post ACL reconstruction without improvement in knee-specific biomechanics. To further investigate this discrepancy, we additionally analyzed knee extensor and flexor muscle strength, and movement quality in the forward lunge (subjective and objective evaluations) and performed a full lower limb biomechanical analysis of the forward lunge movement. We included 12 patients with an ACL injury (tested before and after ACL reconstructive surgery) and 15 healthy controls from the previous study to the current investigation. Outcome measures were obtained pre and ~11 months post ACL reconstruction for the patients and at a single time point for the controls. Objective movement quality in the patients with an ACL injury showed an improvement from their pre reconstruction surgery visit to the post reconstruction visit but this was not observable in the subjective evaluation. Knee extensor muscle strength declined after the ACL reconstruction by 29% (p = 0.002) and both knee extensors (p < 0.001) and flexors (p = 0.027) were weaker in the patients post ACL reconstruction compared to healthy controls. ACL injured patients had an altered movement strategy in the forward lunge with reduced knee extensors contribution and increased hip extensor contribution compared to the controls both before and after the reconstruction. The altered movement strategy was associated with knee extensor muscle strength. This explorative study with a limited sample size found that clinicians should be aware that significant functional deficits in the knee extensor muscles, both in isolated muscle strength testing and during a functional movement, may be present although patients perceive an improvement in their knee function and present good functional performance without obvious movement quality issues.

A biomechanical approach to study lunge in fence athletes

Fencing requires neuromuscular coordination, strength, and power, and it has a high impact on the musculoskeletal system [1–5]. The lunge is the most important strike action. It is produced with explosive power and surprises the opponent to score points. The lunge starts from the armed arm, which must be moved as quickly as possible toward the opponent, combined with lower body movements to provide a boosting action [4]. The present study aims at assessing kinematics and electromyographic differences between tasks and categories. The participants were 28 male and female, élite and recreational fencers, practicing foil and épée. The age ranged from 8 to 35 years old. Anthropometric and biographical information were taken. Kinematics data were acquired using a wearable inertial system BTS G-SENSOR2, positioned on the L5 vertebra. Four wearable EMG probes BTS FREEEMG 1000 were used to detect EMG signal of Deltoideus Anterior (DLTA) and Rectus femoris (RF) both on the armed side; Erector Longissimus muscle (LONG) and Gastrocnemius medialis (GAM), on the opposite one. These devices were synchronized by the acquisition software BTS EMG-Analyzer. Muscles' MVC and two trials of lunge (AF), step forward lunge (AA) and step backward lunge (DA) were taken. Data were processed with MATLAB and Tracker. VWilcoxon’s effect size for continuous variables and prevalence differences for categorical ones. Age and anthropometric measures were statistically different between the two categories (P < 0.05). No statistically significant differences are observed between the sexes, excluding thigh circumference (P < 0.05). The normalized distances and x-axis ROM between tasks and the y-axis ROM in the second trial (AA), the mean normalized muscle activation of DLTA, RF, and GAM between categories were statistically different (P <0.05). No significant statistical differences in muscle activation patterns were observed between different categories. Each correlation coefficient was interpreted based on a previously described classification using similar variables: 0-0.4 (weak), 0.4-0.7 (moderate), and 0.7-1.0 (strong). Table 1 summarizes the results observed from the correlation, the direction of the arrow stands for the direction of correlation (positive or negative), while the number of arrows is the intensity of correlation (weak, moderate, or strong). It is important to emphasize the negative correlation between lunge time and activation intensity of the LONG muscle, as well as the positive correlation between lunge distance and activation intensity of the GAM muscle. Differences have been observed in some kinematic and electromyographic parameters among categories and tasks. No substantial difference in muscle patterns is observed between different categories. Furthermore, correlations have emerged between muscular activity and spatiotemporal variables of movement: a greater rapidity of movement is associated with greater activity of the LONG, because it is balance responsible. A longer lunge distance is related to a greater activity of the GAM (boosting muscle).

Effects Of Step Speed On Anterior Cruciate Ligament Loading During Forward Lunge

Effects Of Step Speed On Anterior Cruciate Ligament Loading During Forward Lunge