Drop Landing Research Articles

FIFA 11+ Kids program effects on jump kinetics in soccer players – A randomized controlled clinical trial

ABSTRACT This study aimed to analyse the effects of the FIFA 11+ Kids programme on jump kinetics in soccer players. Twenty-four athletes (aged 9–11 years) were randomly allocated to the following groups: 1) the FIFA 11+ Kids programme (FT, n = 12), and 2) control training (CT, n = 12). Kinetic assessments of vertical jump (VJ), drop landing (DL), and anterior jump + maximum vertical jump (AJ) were performed on a force platform before and after eight weeks of training. Post-intervention impulse peak force and maximum impulse force (VJ) were significantly greater than the baseline values in the FT group (P < 0.001). Post-intervention landing peak force values for the first and second landings (DL) were significantly greater than the baseline values in the FT group (P = 0.01 and P = 0.05, respectively). Post-intervention landing peak force in the first landing (AJ) was significantly greater than the baseline values in the FT group (P = 0.005). The FT was effective in improving the impulsion performance during VJ. However, it increased the landing forces during DL and VJ.

Regression model for predicting knee flexion angles using ankle plantar flexion angles, body mass index and generalised joint laxity

ABSTRACT Increased knee flexion angles are associated with reduced non-contact anterior cruciate ligament (ACL) injury risks. Ankle plantar flexion angles and internal risk factors could influence knee flexion angles, but their correlations are unknown. This study aimed to establish and validate a regression model to predict knee flexion angles using ankle plantar flexion angles, body mass index (BMI) and generalised joint laxity (GJL) at initial contact of single-leg drop landings. Thirty-two participants performed single-leg drop landings from a 30-cm-high platform. Kinematics and vertical ground reaction forces were measured using a motion capture system and force plate. A multiple regression was performed, and it was validated using a separate data set. The prediction model explained 38% (adjusted R2) of the change in knee flexion angles at initial contact (p = 0.001, large effect size). However, only the ankle plantar flexion angle (p < 0.001) was found to be a significant predictor of knee flexion angles. External validation further showed that the model explained 26% of knee flexion angles (large effect size). The inverse relationship between ankle plantar flexion and knee flexion angles suggests that foot landing strategies could be used to increase knee flexion angles, thereby reducing non-contact ACL injury risks.

Effect of Six Weeks of Plyometric Training with Feedback on Maximum Knee Flexion and Maximum Vertical GRF on Drop Landing Technique of Male Basketball Players With Chronic Ankle Instability

Background and Aims: With respect to the prevalence of chronic ankle instability and adverse consequences, such as neuromuscular dysfunction of the proximal joints, the implementation of preventive proceeding in the proximal limb of the ankle is very necessary. Therefore, the present study was done to investigate the effect of six weeks of plyometric training with feedback on maximum knee flexion and maximum vertical GRF on the drop landing technique of male basketball players with chronic ankle instability. Methods: The present study has a quasi-experimental research design. Twenty-four male basketball players with chronic ankle instability participated in this study. After identifying individuals using the Cumberland Ankle Instability Tool, athletes were divided into two experimental groups (n=12) and a control (n=12) group. Evaluation of maximum knee flexion and maximum vertical ground reaction force was conducted using ten cameras and two distinct forces, respectively. The participants in the experimental groups performed plyometric training with feedback for six weeks. After examining the normality of data by the Shapiro-Wilk test, a paired t-test was used to compare differences within groups and an independent t-test was used to compare differences between groups. Results: The results showed that six weeks of plyometric training with feedback on maximum knee flexion and maximum vertical GRF on drop landing technique of male basketball players with chronic ankle instability significantly increased maximum knee flexion and reduced the maximum vertical GRF (P≤0.05). Conclusion: Adding plyometric training with feedback to the chronic ankle instability basketball program to prevent subsequent damage later in the proximal limb is recommended.

Effects of kinesiology tape with training shoes on ankle proprioception in individuals with chronic ankle instability during drop landing

Introduction: Kinesiology tape (KT) has been thought to be useful in enhancing performance and preventing injuries. However, it was unknown whether use of KT while wearing training shoes could improve ankle proprioception in individuals with chronic ankle instability (CAI) in functional movement, such as drop landing. The current research was to determine the effects of KT only and KT with training shoes on ankle proprioception in individuals with CAI during drop landing task.

Variability in Touchdown Technique and Ground Reaction Force Components during Drop Landing of 107 Healthy Adults.

The article's abstract is not available.

Drop Landing Biomechanics in Individuals With and Without a Concussion History.

Research has identified an increased risk of lower extremity injury postconcussion, which may be due to aberrant biomechanics during dynamic tasks. The purpose of this study was to compare the drop landing biomechanics between individuals with and without a concussion history. Twenty-five individuals with and 25 without a concussion history were matched on age (±3y), sex, and body mass index (±1kg/m2). Three-dimensional landing biomechanics were recorded to obtain dependent variables (peak vertical ground reaction force, loading rate, knee flexion angle and external moment, knee abduction angle and external moment, and knee flexion and abduction angle at ground contact). A 1-way multivariate analysis of variance compared outcomes between groups. There was no difference in drop landing biomechanics between individuals with and without a concussion history (F10,39 = 0.460, P = .877, Wilk Λ = .918). There was an effect of time since concussion on knee flexion characteristics. Time since most recent concussion explained a significant amount of variation in both peak (ΔR2 = .177, β = -0.305, ΔP = .046) and initial ground contact (ΔR2 = .292, β = -0.204, ΔP = .008) knee flexion angle after covarying for sex and body mass index. Therefore, time since concussion should be considered when evaluating biomechanical patterns.

Wearing Cushioning Shoes Reduce Load Rates More Effectively in Post-Fatigue than in Pre-Fatigue during Landings.

Simple SummaryAthlete experience high impact forces during landing, which is a contributing factor to injury risk potentials. As a potential factor of affecting the impact force, previous study of the effects of footwear cushioning effect on landing biomechanics were inconsistent. Furthermore, limited efforts have been exerted on the relationship between footwear cushioning and fatigue. In this study, the footwear cushioning effects on bipedal landing biomechanics before and after acute exercise-induced fatigue protocol were explored. The results of this study suggest that footwear cushioning can reduce landing-related rearfoot impact forces regardless of fatigue conditions. In a situation where the neuromuscular activity is reduced or absent, e.g., post-fatigue, wearing better cushioning shoes show superior attenuation, as indicated by low forefoot and rearfoot impacts.Purpose: this study aimed to investigate the footwear cushioning effects on impact forces and joint kinematics of the lower extremity during bipedal drop landings before and after acute exercise-induced fatigue protocol. Methods: in this case, 15 male collegiate basketball athletes performed drop landings from a 60 cm platform wearing highly-cushioned shoes (HS) and less cushioned shoes (control shoes, CS) before and after acute fatigue-inducing exercises (i.e., shuttle run combined with multiple vertical jumps). Force plates and motion capturing systems were synchronised to measure ground reaction forces and kinematic data during drop landings. Maximum jump height was analysed with one-way ANOVA. Two-way repeated measure ANOVAs were performed on each of the tested variables to examine if there was significant main effects of shoe and fatigue as well as the interaction. The significance level was set to 0.05. Results: rearfoot peak impact forces and loading rates significantly reduced when the participants wore HS in pre- and post-fatigue conditions. The peak loading rates in forefoot significantly reduced when HS were worn in post-fatigue. Compared with pre-fatigue, wearing HS contributed to with 24% and 13% reduction in forefoot and rearfoot peak loading rates, respectively, and the occurrence times of first and second peak impact forces and loading rates were much later. In the post-fatigue, a significant increase in the initial contact and minimum angles of the ankle were observed in HS compared with CS. Conclusion: these findings suggest that footwear cushioning can reduce landing-related rearfoot impact forces regardless of fatigue conditions. In a situation where the neuromuscular activity is reduced or absent such as post-fatigue wearing better cushioning shoes show superior attenuation, as indicated by lower forefoot and rearfoot impacts.

Biomechanical responses to landing strategies of female artistic gymnasts

ABSTRACT Inconsistencies between sexes in the landing criteria provided by the international gymnastics governing body (FIG) may predispose female gymnasts to lower extremity injury. This study aimed to investigate lower extremity biomechanics when performing the male and female landing strategy. Seven collegiate, female gymnasts (age: 20.5 ± 1.2 years, height: 1.64 ± 0.06 m, mass: 60.4 ± 10.2 kg) performed drop landings using the prescribed women’s and men’s landing strategy. Kinematic and kinetic data from 10 trials of each landing strategy were collected. Differences between landing strategy at individual and group level for key injury risk variables of the lower limb were explored. Group differences (p ≤ .05) were reported in the sagittal range of motion (ROM) at the knees and hips, with the men’s landing strategy eliciting a larger ROM decelerating the body upon impact. Large inter and intra-individual variation was apparent with different movement responses shown across individuals and demonstrating degeneracy as gymnasts satisfied the overall landing objective. These results indicate an individually favoured landing strategy to fulfil the informational constraints and hence supporting the use of a single-subject design. The current study emphasises the potential injury risk associated with the different informational constraints placed on females’ landing strategy by the FIG, whilst recognising the individual gymnasts’ task response. Highlights An increase in the range of motion at the knee and hip may support the recommendation of the men’s landing style. Gymnasts appear to utilise individual landing strategies to complete the landing objective, supporting the use of a single-subject design.

Comparisons of Vastus Lateralis Architecture and Biomechanical Characteristics during Drop Landing in Young Football Players

PURPOSE: The purpose of this study was to compare the vastus lateralis (VL) architecture and exercise biomechanics indices during drop landing in young football players.METHODS: Fifteen young football players were divided into a long vastus lateralis muscle fascicle length group (LFG, n=8) and short vastus lateralis muscle fascicle length group (SFG, n=7). All of the participants performed drop landing onto the ground reaction force plate from a platform 30 cm high. The muscle activities of the VL, tibialis anterior (TA), and gastrocnemius (GCM), angular velocity, and ground reaction force in the ankle, knee, and hip joints were measured during drop landing.RESULTS: The VL muscle activity (&lt;i&gt;p&lt;/i&gt;=.032), ankle ground contact angle (&lt;i&gt;p&lt;/i&gt;=.027), ankle maximum flexion angle (&lt;i&gt;p&lt;/i&gt;=.014), knee maximum flexion angle (&lt;i&gt;p&lt;/i&gt;=.007), and ground reaction force per body weight (&lt;i&gt;p&lt;/i&gt;=.032) were significantly higher in the LFG than in the SFG. Muscle activity of the TA (&lt;i&gt;p&lt;/i&gt;=.017), ankle (&lt;i&gt;p&lt;/i&gt;=.033), and hip (&lt;i&gt;p&lt;/i&gt;=.045) time to stability and the ground reaction force time to stability (&lt;i&gt;p&lt;/i&gt;=.043) were significantly lower in the LFG than in the SFG. Muscle activity of the GCM (&lt;i&gt;p&lt;/i&gt;=.053) and knee time to stability (&lt;i&gt;p&lt;/i&gt;=.057) tended to be lower in the LFG than in the SFG.CONCLUSIONS: These results confirmed that muscle activity, angular velocity, and ground reaction force variables during drop landing are affected by the VL muscle fascicle length in young football players.

Identification of the most effective muscles in landing impact forces

The aim of this study was to evaluate the role of the main lower limb muscles in increasing or decreasing each lower limb joint impact force during drop landing. To do so, the body was modeled by a four-link musculoskeletal model consisting of eight main Hill-type muscles. Different drop landing scenarios were modeled by changing the activation levels of the considered muscles. In each landing simulation, the impact GRF and impact joint forces were obtained. In order to compare and rank the muscles with respect to their effect on each impact force, a computationally feasible zero-one (off-on) muscle activation analysis was proposed. The proposed approach revealed important features regarding the relation between different impact forces and muscle activations. Specifically, the results can be interpreted in terms of the role that each muscle potentially plays in causing or preventing certain injuries. Moreover, the results obtained from the analysis were further used to classify the muscles into four categories, depending on the effect they have on each impact force. The proposed theoretical analysis is seen to be a promising tool in predicting the role of muscles and their order of importance in the generation of lower limb impact forces in landing, without the need for experimental tests.

اثر چهار هفته تمرینات ثبات مرکزی بر روی برخی از متغیرهای کینماتیکی اندام تحتانی ورزشکاران دختر دارای ‏بی‌ثباتی عملکردی مچ پا‎ ‎حین تکلیف افت فرود تک پا

Purpose:Functional ankle instability is one of the most common residual and debilitating symptoms of acute ankle sprain which usually makes the athlete to be out of training program for a while. This study aimed to investigate the effect of four weeks core stability training on some lower extremity kinematics variables in athletes with functional ankle instability during a single-leg drop landing taskMethod:In this semi-experimental research, study population included 24 athletes with functional ankle which were divided into two experimental (n=12), and control (n=12) groups. To assess the drop-landing task with functional instability foot,240 Hz frequency motion analysis system was used. The recorded movements were analyzed by Nexus 2.6 version. The hip, knee, and ankle angles were extracted on the sagittal plane, and finally, repeated measure ANOVA and Bonferroni posthoc were used to compare two groups (p≤0.05).Result:There was no significant difference in the angle of the ankle after four weeks training (p≥0.05). However, in the angle of the hip and knee were found a significant difference from pretest to post-test (p≤0.05)Conclusion:The results indicated that four weeks core stability training improves kinematics of landing in athletes with functional ankle instability, and it seems that these exercises can be a method of preventing re-injury of the ankle.

Landing mechanics of basketball and volleyball athletes: a kinematic approach

PurposeSingle-leg landing is frequent in basketball and volleyball, two sports with high incidence of anterior cruciate ligament injuries. The similarity in the number of landings between these sports could be the culprit of the high incidence of injuries. However, the comparison of knee joint motion during landings in both sports has yet to be investigated. This study aimed to contrast the knee kinematics of basketball and volleyball athletes during a single-leg landing task.MethodsOverall, 10 male athletes, 5 in basketball (181.4 ± 6.7 cm; 93.21 ± 33.06 kg) and 5 in volleyball (178.4 ± 6.6 cm, 79.11 ± 6.46 kg) performed single-leg drop landings. Differences between the groups were verified with the superposition of 95% confidence intervals. Additionally, the probability approach was applied with magnitude-based inferential statistics calculated to compare individual instants (40 ms after the initial ground contact, maximum flexion, and abduction).ResultsDifferent knee movement patterns were detected between the groups. While volleyball athletes showed greater knee flexion, basketball players exhibited greater knee abduction. The magnitude-based inference also demonstrated that volleyball athletes presented higher values in the sagittal plane.ConclusionsBasketball athletes exhibited greater valgus in the instants before and after ground contact. In addition, volleyball athletes showed greater knee flexion during the single-leg drop landing.

Changes in landing mechanics using augmented feedback: 4-Week training and retention study

ContextNon-contact ACL injuries are common in female athletes during landing tasks. Post-trial performance-based feedback may be an effective method to reduce landing forces and knee valgus during landing. Information regarding the retention of these changes based on such training is generally lacking for weekly and monthly retention. ObjectiveTo determine the effectiveness of post-trial feedback training to promote and retain changes in vertical ground reaction force (vGRF) and knee to ankle (K:A) ratio during a dual task drop landing in female collegiate athletes. DesignRepeated measures; SettingUniversity campus. Participants22 female collegiate athletes. Materials and methodsDual task drop landings were performed over 4 successive weeks with immediate post trial feedback on peak vGRF, symmetry, and K:A ratio. K:A ratio was a surrogate measure for knee valgus in drop landing. ResultsSignificant decreases in vGRF and increases in K:A ratio were found within training sessions (p = .000). Both variables were retained each week over the 4 weeks. ConclusionUsing a custom portable clinical feedback system may be an effective tool in reducing peak vGRFs and knee abduction angles during a drop landing over a 4-week period in female collegiate athletes.

An Investigation of Differences in Lower Extremity Biomechanics During Single-Leg Landing From Height Using Bionic Shoes and Normal Shoes.

Bionic shoes utilizing an actual foot shape sole structure can alter lower limb’s biomechanics, which may help in the development of specific training or rehabilitation programs. The purpose of this study was to investigate the biomechanical differences in the lower limb during a single-leg landing task using bionic shoes (BS) and normal shoes (NS). Fifteen healthy male subjects participated in this study, sagittal, and frontal plane data were collected during the landing phase (drop landing from 35 cm platform). Our study showed that BS depicted a significantly greater minimum knee flexion angle at initial contact (p = 0.000), a significantly greater minimum (initial contact) hip flexion angle at initial contact (p = 0.009), a significantly smaller sagittal plane total energy dissipation (p = 0.028), a significantly smaller frontal plane total energy dissipation (p = 0.008), a significantly smaller lower limb total energy dissipation (p = 0.017) than NS during the landing phase. SPM analysis revealed that BS depicted a significantly smaller knee joint vertical reaction force during the 13.8–19.8% landing phase (p = 0.01), a significantly smaller anterior tibia shear force during the 14.2–17.5% landing phase (p = 0.024) than NS. BS appears to change lower limb kinematics at initial contact and then readjust the landing strategies for joint work and joint reaction force, thereby reducing the risk of lower limb skeletal muscle injury. BS have great potential for future development and application uses, which may help athletes to reduce lower limb injury risk.

Determination of the Strongest Factor and Component in a Relationship between Lower-Extremity Assessment Protocol and Patient-Oriented Outcomes in Individuals with Anterior Cruciate Ligament Reconstruction: A Pilot Study.

Although the Lower-Extremity Assessment Protocol (LEAP) assesses multidimensional aspects of a patient with anterior cruciate ligament (ACL) injury, there is a need to reduce the dimensionality of LEAP items to effectively assess patients. Therefore, the present study aimed to establish the validity of LEAP and to determine associated factors and components in a relationship between LEAP and the International Knee Documentation Committee (IKDC) questionnaire. Fifteen patients who had ACL reconstruction more than 1 year and less than 5 years earlier were recruited. Patients performed LEAP, including muscular strength, fatigue index, static balance, drop landing, and functional hopping assessment. They also completed the IKDC questionnaire and the Tegner Activity Score. Factor analysis and stepwise regression analysis were performed. The 14 components of LEAP were categorized into four factors (functional task, muscle strength, neuromuscular control, and fatigue), which accounted for 83.8% of the cumulative variance by factor analysis. In the stepwise regression analysis, the functional task (R2 = 0.43, p = 0.008) in factors and single-leg hop (R2 = 0.49, p = 0.004) in components were associated with patient-oriented outcomes, respectively. In conclusion, the functional task and single-leg hop may be used for providing valuable information about knee joints to patients and clinicians.

The effects of strength training upon front foot contact ground reaction forces and ball release speed among high-level cricket pace bowlers

ABSTRACT The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance.

Acute Effect of Ankle Kinesio™ Taping on Lower-Limb Biomechanics During Single-Legged Drop Landing.

Chronic ankle instability is documented to be followed by a recurrence of giving away episodes due to impairments in mechanical support. The application of ankle Kinesiotaping (KT) as a therapeutic intervention has been increasingly raised among athletes and physiotherapists. This study aimed to investigate the impacts of ankle KT on the lower-limb kinematics, kinetics, dynamic balance, and muscle activity of college athletes with chronic ankle instability. A crossover study design. Twenty-eight college athletes with chronic ankle sprain (11 females and 17 males, 23.46 [2.65]y, 175.36 [11.49]cm, 70.12 [14.11]kg) participated in this study. The participants executed 3 single-leg drop landings under nontaped and ankle Kinesio-taped conditions. Ankle, knee, and hip kinematics, kinetics, and dynamic balance status and the lateral gastrocnemius, medial gastrocnemius, tibialis anterior, and peroneus longus muscle activity were recorded and analyzed. The application of ankle KT decreased ankle joint range of motion (P = .039) and angular velocities (P = .044) in the sagittal plane, ground reaction force rate of loading (P = .019), and mediolateral time to stability (P = .035). The lateral gastrocnemius (0.002) and peroneus longus (0.046) activity amplitudes also experienced a significant decrease after initial ground contact when the participants' ankles were taped, while the application of ankle KT resulted in an increase in the peroneus longus (0.014) activity amplitudes before initial ground contact. Ankle lateral supports provided by KT potentially decreases mechanical stresses applied to the lower limbs, aids in dynamic balance, and lowers calf muscle energy consumption; therefore, it could be offered as a suitable supportive means for acute usage in athletes with chronic ankle instability.

Effects of ankle instability type and bilateral leg on lower extremity kinetics during drop-landing

The purpose of this study was to investigate the analysis of the postural stability and leg stiffness according to the ankle instability types and bilateral legs during drop landing. Methods: Total 14 male athletes (n=7: mechanical ankle instability, n=7: functional ankle instability) Participants in the experiment. The leg stiffness, leg length, peak vertical force, loading rate, as well as the DPSI (medial-lateral [ML], anterior-posterior [AP], vertical [V], dynamic postural stability index) during drop landing were calculated. To analyze the variables measured in this study, SPSS version 21.0 was used to calculate the mean and standard deviation, while a two-way ANOVA was used to evaluate the ankle instability types (MAI, FAI) with landing leg (left: dominant, right: non-dominant leg) results. Dimensionless leg stiffness and change of leg lengths showed increased with significantly in non-dominant leg and MAI type than in dominant leg and FAI type. This resulted from decrease in the leg lengths with leg stiff. MLSI showed increased with significantly in dominant leg than in non-dominant leg during drop landing. Mechanically unstable individuals demonstrated increased leg stiffness, which may increase risk of musculoskeletal. Also, mechanically unstable participants demonstrated greater loading rate variability, which may indicate difficulty mitigating landing forces with lax ligaments.

Hybrid Parallel Compliance Allows Robots to Operate With Sensorimotor Delays and Low Control Frequencies

Animals locomote robustly and agile, albeit significant sensorimotor delays of their nervous system and the harsh loading conditions resulting from repeated, high-frequent impacts. The engineered sensorimotor control in legged robots is implemented with high control frequencies, often in the kilohertz range. Consequently, robot sensors and actuators can be polled within a few milliseconds. However, especially at harsh impacts with unknown touch-down timing, controllers of legged robots can become unstable, while animals are seemingly not affected. We examine this discrepancy and suggest and implement a hybrid system consisting of a parallel compliant leg joint with varying amounts of passive stiffness and a virtual leg length controller. We present systematic experiments both in computer simulation and robot hardware. Our system shows previously unseen robustness, in the presence of sensorimotor delays up to 60 ms, or control frequencies as low as 20 Hz, for a drop landing task from 1.3 leg lengths high and with a compliance ratio (fraction of physical stiffness of the sum of virtual and physical stiffness) of 0.7. In computer simulations, we report successful drop-landings from 3.8 leg lengths (1.2 m) for a 2 kg quadruped robot with 100 Hz control frequency and a sensorimotor delay of 35 ms.

Parametric analysis of landing injury : The effect of landing posture and joint displacement.

During landing, the lower limb joints work concertedly to reduce landing forces. Changing the biomechanics of one joint can alter landing strategies in other joints thus affecting the probability of injury. Therefore, understanding the mutual effects between the joints is crucial for the prevention of lower extremity injuries. The purpose of this study is to evaluate the effect of joint displacement and initial contact posture on the impact forces and joint kinematics during drop landing, via computational modeling. The impact dynamics of drop landing is modeled by a three link planar model. Different landing scenarios are then simulated to investigate how restricting the displacement of one joint and changing its initial contact angle affect the other joints' ranges of motion, the trunk motion, and the impact forces. Our study suggests that the impact force increases by up to [Formula: see text], [Formula: see text] and [Formula: see text], by restricting the hip, knee and ankle joints, respectively. Restricting each one of the hip and knee joints decreases the displacement of the other one. The association between the ankle displacement and the hip/knee motion depends on joints' stiffness and landing posture. Moreover, changing the landing posture affects the joints kinematics and impact forces significantly. A safe landing posture is a fore-foot landing with knee flexion angle of around 30° to 40° and a foot-ground angle of 40° to 55°, which decreases the impact force by more than [Formula: see text] in comparison to the erect posture with horizontal foot. The obtained results are of practical importance in training landing skills and designing force-reducing external components.