Squat Jump Research Articles

Lower Limb Skeletal Robustness Determines the Change of Directional Speed Performance in Youth Ice Hockey.

The factors that influence the on-ice change of directional speed (COD) of ice hockey players remain unclear. Therefore, this study aimed to determine which off-ice and anthropometric variables determine hockey COD with and without a puck. Thirty-two elite ice hockey players (age: 17.64 ± 1.02 years, body height: 180 ± 7.5 cm, body mass: 76.4 ± 7.8 kg) performed squat jumps, broad jumps, countermovement jumps, and pull-ups and were assessed on agility office and on-ice, with and without a puck. Anthropometric characteristics were determined according to the modified somatotype method. A moderate correlation (r = 0.59-0.6) was observed among all agility tests, between on-ice agility with a puck and lower limb skeletal robustness (r = 0.45), and between on-ice agility with a puck and sit-and-reach scores (r = -0.50). Agility without a puck correlated with squat jump height (r = -0.36). Multiple regression analysis indicated that off-ice agility (β = 0.51) and skeletal robustness of the lower limbs (β = 0.35) determined (R2 = 0.41) on-ice agility with a puck. Players' COD was assessed by Illinois tests of agility off-ice and on-ice, with and without a puck; each of these tests moderately predicted the others, but differed in their physical constraints. Players with higher skeletal robustness used more strength and power to achieve COD performance, while players with lower skeletal robustness used techniques and skills to achieve COD, resulting in superior COD performance with a puck compared to stronger athletes. CODs with and without a puck are discrete skills requiring different abilities.

Effects of repetitive different jump pre-conditioning activities on post activity performance enhancement

Purpose: The purpose of this study was to investigate effects of repetitive different jump pre-conditioning activities on post activity performance enhancement (PAPE). Methods: Twenty-six male sports science faculty students who were physically active between the ages of 18-22 to participate in the study were divided into a squat jump group (SJG) (n= 14, age 20.0 ± 1.3 year, height: 175.1 ± 6.7 cm, body weight: 71.9 ± 6.9 kg) and a countermovement jump group (CMJG) (n= 12, age 20.1 ± .9 year, height: 175.3 ± 7.9 cm, body weight: 71.3 ± 8.2 kg). Squat jump (SJ) and countermovement jump (CMJ) tests were performed before the pre-conditioning activity, 4 min and 10 min after the pre-conditioning activity. SJG performed SJ and CMJG performed CMJ as the pre-conditioning activity with three reps. One-way repeated measures ANOVA was performed to determine the PAPE effect of pre-conditioning activities, SJ and CMJ on the variables flight time (FT), jump height (JH) and power (P) in SJ and CMJ tests after 4 min and 10 min. Significance level was taken as P< .05. Results: Statistically significant differences were found as PAPE effect in SJ test FT, JH and P variables in the SJG at 4 min and 6 min after the pre-conditioning activity SJ (F(2;12)= 10.607; P= .002, η2= .639 for FT; F(2;12)= 9.323; P= .004, η2= .608 for JH and P). In CMJG, there were no statistically significant differences in PAPE effect in the CMJ test FT, JH, and P variables 4 min and 8 min after the pre-conditioning activity CMJ. Conclusions: In conclusion, the time-dependent differences in SJ and CMJ performance of PAPE effects caused by repetitive pre-conditioning activities, SJ and CMJ, showed the importance of determining the exercises that will create a pre-conditioning and optimal rest periods for post-PAPE performance. Keywords: Pre-conditioning activity, post activity performance enhancement, squat jump, counter-movement-jump

Relationship between vertical jump tests and ice-skating performance in junior Polish ice hockey players

The aim of this study was to determine the relationships between vertical jumps (VJ) and various on-ice skating performances of junior ice hockey players (n = 19). The three modes of VJ or off-ice measures were countermovement jump with arm swing (CMJ), squat jump (SJ) and depth drop jump (DDJ). The on-ice skating performance was measured by the skating multistage aerobic test (SMAT), forward and backward acceleration test, top speed test, and repeated sprint ability (RSA) test. The relationships between the variables were quantified using Pearson's product-moment correlation. DDJ showed a significant positive correlation with forward average skating speed (FASS) (r = 0.62) and strong correlations with backward average skating speed (BASS) (r = 0.81), and maximum skating speed (MSS) (r = 0.71). SJ was found to be strongly correlated with BASS (r = 0.82) and MSS (r = 0.76), whereas the only on-ice performance that significantly correlated with CMJ was BASS (r = 0.68). All three modes of VJ were inversely and non-significantly correlated with performance decrement index and fatigue index, as determined by the RSA test. SMAT was not significantly correlated with either VJ or RSA. Correlations between all three modes of VJ tests were significant. Therefore, this study concludes that: (1) DDJ can be used as a predictor of all the ice skating speed tests, whereas SJ can predict BASS and MSS. CMJ, on the other hand, can predict the performance of only BASS. (2) RSA performance cannot be predicted from CMJ, SJ, or DDJ tests, and (3) neither any of the VJ nor RSA can predict skating endurance of junior ice hockey players.

The load-velocity relationship in the jump squat exercise.

The purpose of this study was to test the load-velocity relationship in the jump squat (JS) exercise using three different velocity parameters (mean velocity [MV], mean propulsive velocity [MPV], and peak velocity [PV]). Twenty-six male rugby union players (24.3 ± 3.9 years; 1.81 ± 0.09 m; 101.3 ± 15.4 kg) performed a progressive loading test in the JS with loads corresponding to 20, 40, 60, and 80% of the half-squat 1RM (equivalent to 24, 46, 70, and 94% of the estimated JS-1RM). MV, MPV, and PV were continuously recorded during all attempts using a linear velocity transducer. Linear regression models were used to determine the relationships between JS loads and MV, MPV, and PV. Bar-velocity outputs demonstrated high levels of consistency and reliability (coefficient of variation ≤ 5% and intraclass correlation coefficient ≥ 0.90). The predictive power of MV, MPV, and PV were ≥ 91%, for all tested variables (P < 0.0001). The equations and bar-velocity values provided in this study can be used by coaches to precisely determine and prescribe JS training loads, from verylight to heavy loading conditions (i.e., ~20-100% JS 1RM).

Predictors of linear sprint performance in professional football players.

The purpose of this study was to analyze the relationship between sprint performance (time), and strength and power capabilities in football players. A total of 33 professional Portuguese football players performed isokinetic strength assessments, countermovement jumps (CMJ), squat jumps (SJ), and 10, 20 and 30 m sprints. Pearson's correlation (r) was used to determine the relationships between variables. Concentric knee extensor torque at 180° · s-1 was largely-to-very largely correlated with 10 m (r = -0.726), 20 m (-0.657) and 30 m sprints (r = -0.823). Moderate inverse correlation were observed between CMJ (r = -0.425 and r = -0.405) and SJ height (r = -0.417 and r = -0.430), and 20 m and 30 m sprint performance, respectively. Multiple linear regression combining KEcon 180° · s-1 and KFcon 180° · s-1 demonstrated that the model was significant for predicting 10 m sprint time (F (2, 8) = 5.886; R 2 = 0.595). The model combining SJ, CMJ and KEcon 180° · s-1 was also significant for predicting 20 and 30 m sprint times (F (3, 7) = 2.475; R 2 = 0.515 and F (3, 7) = 5.282; R 2 = 0.562; respectively). In conclusion, peak torque at higher velocities and vertical jump performance correlates significantly with linear sprint performance (time). For practitioners seeking to improve linear sprint performance in football players, evaluation of high speed strength and vertical jump indices should be undertaken.

A comparative study of vertical jump parameters in men's college basketball and volleyball players

This study aimed to compare lower limb strength disparities between male college volleyball and basketball players in four distinct vertical jump types. We recruited 100 second-level (above the national standard) male college athletes (50 basketball and 50 volleyball players) from Capital University of Physical Education and Sports who volunteered to participate. We assessed the performance of each athlete with regards to the squat jump (SJ), countermovement jump (CMJ), continuous jump with straight legs (CJs), and continuous jump with bent legs (CJb). Data analysis was performed by independent samples t-tests in SPSS version 25.0. software. In the CMJ test, volleyball players had a significantly higher vertical jump displacement (VJD; p = 0.047, t = −2.018), squat displacement (SD; p = 0.005, t = −2.883), peak force (p = 0.023, t = −1.964), and peak velocity (p = 0.011, t = −1.687) than basketball players. In the SJ test, volleyball players had a significantly higher VJD (p = 0.041, t = −1.21) and SD (p = 0.008, t = −1.46) than basketball players. In the CJs test, volleyball players had a significantly higher average vertical jump displacement (AVJD; p = 0.042, t = −2.067) than basketball players. In the CJb test, volleyball players had a significantly higher AVJD (p = 0.001, t = −3.448), average squat displacement (p = 0.017, t = −2.44), and average contact time (p = 0.045, t = −2.038) than basketball players. The overall vertical jump ability of college volleyball players was better than that of college basketball players. CMJ, SJ, CJs and CJb training should be included in daily training sessions and considered in the selection of basketball and volleyball players. In addition, coaches can use fast twitch Fibers, the effect of pre-stretch and k as the main evaluation indicators to assess daily training progress.

RELAÇÃO ENTRE O DESEMPENHO DE SALTO E SPRINT EM VELOCISTAS ADOLESCENTES

ABSTRACT Objectives: This study aimed to examine the relationship between vertical jumping at forces of specific time phase and sprint performance in teenage sprinters. Methods: Fifteen male teenage sprinters (age: 14±2 years, height: 168±2 cm, weight: 61±1 kg) participated in the study. The subjects performed the following bilateral/unilateral jumps on a force platform: a) squat jump (SJ), b) unilateral SJ (USJ), c) 40cm drop jump (DJ), and d) 20cm unilateral DJ (UDJ). The 60m sprint test was administered on the second day. Brower split timers were positioned to record subjects’ 5m, 10m, 50m and 60m split times. The variables for inclusion were vertical jump height, maximum force, and force output at 120ms in all jumps and sprint time measures. Results: The results of the Pearson Product Moment Correlation analysis showed that SJ120ms was correlated to 5m and USJ120ms was correlated to 10m. UDJ120ms showed a stronger correlation with 50m than DJ120ms. Although significant correlations using maximum force and height were observed, there were inconsistent results between bilateral and unilateral jumps. Conclusion: Our results highlighted that jumps that have similar form with certain force outputs at specific event timing could more precisely predict sprint performance in teenage sprinters. USJ120ms and UDJ120ms could better predict the acceleration (10m) and high-speed phase (50m) in sprint performance, respectively. Moreover, coaches and practitioners should be cautious when using only jump height or maximum force to predict sprint performance, since the results could be inaccurate when specific movement variables are not thoughtfully considered. Level of evidence III.

The Comparison of Unilateral and Bilateral Training Effect to Changes in Speed and Speed-Strength Abilities in Preadolescence Athletes

Introduction: The aim of the study was to compare the effectiveness of unilateral and bilateral training program on changes in the level of speed and speed-strength abilities. Methods: Experimental group 1 (EG1) consisted of 8 young athletes (age = 12.76±1.55 years) and experimental group 2 (EG2) consisted of 8 athletes (age = 12.51±1.59 years) who regularly participate in the training process at a frequency of three times a week. All of our athletes had more than 4 years experiences with regular athletic training 3 times per week prior to this study. During a period of 8 weeks in the preparatory period, such exercises were applied which were performed unilaterally in EG1 and bilaterally in EG2. To determine the effectiveness of take-off training on change in the level of speed and speed-strength abilities, the following tests were performed: relative strength index (RSI), squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), 20 m run from standing start. Results: We found out that in the posttest, the athletes of both groups achieved an improvement in the explosive strength of the lower extremities as well as in the acceleration speed. A significant improvement (p&lt;0.05) was recorded in EG1 in SLJ and in EG2 in RSI. The effect size coefficients showed a large effect in RSI in EG2 and in SLJ in EG1. Conclusion: The results clearly did not confirm a higher effect of the unilateral program in comparison with the bilateral program, but indicated a higher efficiency, especially in the take-off explosiveness of athletes with a unilateral training program.

TREINAMENTO PREVENTIVO DE FORÇA DE LESÕES NA GINÁSTICA AERÓBICA

ABSTRACT Introduction Aerobics is a combination of strength and beauty. The complexity of its movements is extreme, and it is easy to cause injuries from sports training in its athletes. Objective Analyze the effect of strength training on injury prevention in aerobic gymnastics. Methods The total duration of the experiment was 8 weeks, and the athletes in the experimental group were trained three times a week with the help of teachers in a dedicated strength training program. The exercise principle of the control group was to perform physical strength training based on running. The control group did not have the special protocol intervention. Their scores were collected and compared before and after the intervention. Statistical analysis was performed for scientific appreciation of the collected data. Results The scores on the deep squat, obstacle avoidance, front and back squat, scapular girdle joint flexibility, straight leg raising, stable trunk flexions, and rotational stability tests in the experimental group were all statistically differentiated. However, the control group’s scores had little difference, showing a slight decrease. Conclusion It is recommended to insert the presented program into the conventional aerobic gymnastics training, always with changes that adjust the reality of the athletes’ situation, protecting their physical health and improving their competitive level. Level of evidence II; Therapeutic studies - investigation of treatment results.

TREINAMENTO DE FORÇA EXPLOSIVA SOB MEMBROS INFERIORES NO FUTEBOL

ABSTRACT Introduction: Technical movements that mainly include running and jumping are soccer's main sport selection processes. These technical movements demand high requirements of lower limb endurance and explosive strength by athletes. Objective: Study the methods of strength and explosive force training in the lower limbs of soccer players. Methods: The experiment with 40 volunteers lasted 12 weeks and was conducted as a control experiment. The experimental group performed extensive lower limb strength training represented by weight resistance strength training on Monday and Wednesday. In contrast, the control group performed traditional modes of strength training such as half squats and deep squats. Diet was controlled, targeting to minimize the interference of unrelated variables. Results: The scores of the experimental group and the control group were improved and statistically more favorable in the experimental group. Conclusion: The strength training system with weight bearing on the lower limbs used in this study may promote better muscular development of the athletes, improve the explosive power of their lower limbs, and allow better performance on the field, and may be replicated. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

A new approach to preprocessing of EMG signal to assess the correctness of muscle condition

Purpose: Electromyography (EMG) is a technique dealing with the recording and analysis of myoelectric signals formed by physiological variations in the muscle fiber membrane. The voltage potential of surface myoelectrical signals (sEMG) varies over time and depends on the characteristics of the individual subject. One of the main drawbacks of sEMG analysis is that the given acquisition conditions strongly determine the amplitude of the signal. The analysis of sEMG requires appropriate preprocessing, including proper filtering and artifact removal. Moreover, the sEMG data must be converted to a scale standardized for all measurements. This research aimed both to propose a method of sEMG processing to eliminate the occurring disturbances, in particular impulsive artifacts, and to determine the level of muscle excitation based on normalized sEMG. The analysis of muscle excitation level can be applied to assess muscle activity during physical activity. Design/methodology/approach: The proposed algorithm uses set of digital filters, probabilistic distribution and the decomposition of the sEMG signal to attenuate artifacts. Variance analysis of the sEMG derivative is used to determine muscle excitation. The sEMG signals were acquired with the VICON system with the sampling frequency set at 1000 Hz, and processed in MATLAB. During sEMG recordings, standard silver/silver chloride (Ag/AgCl) surface electrodes were used. Findings: The suggested technique was validated using sEMG recorded for eight persons during deep squat. Normalized excitation was determined for the left and right muscles, the rectus femoris, the vastus medialis, and the biceps femoris. Obtained outcomes indicate a possibility to assess the correctness of muscles condition. Originality/value: The combination of the proposed filter and the analysis variance-based thresholding method can effectively eliminate impulse artifacts within the surface myoelectrical signals. Keywords: Spikes disturbance, EMG, Muscle excitation, Filtering, Kurtosis. Category of the paper: Research paper.

TREINAMENTO DA FORÇA E COORDENAÇÃO NOS MEMBROS INFERIORES DE FUTEBOLISTAS

ABSTRACT Introduction: The long distance running and the short distance running shot are common in soccer world, so that soccer presents a higher demand in relation to the strength of lower limbs and motor coordination by the athlete. Objective: Analyze the methods of training lower-limb strength and coordination in soccer. Methods: The experiment-by-control method was adopted. During the 12 weeks of training, the control group performed the traditional mode of lower limb strength training based on deep squat, while the experimental group adopted the global mode of lower limb strength training. The exercise training plans of the experimental group and control group were standardized. Results: The relative performance of the athletes in the experimental group and the control group was improved, however, the developmental effect of the experimental group was more significant. Conclusion: The comprehensive mode of lower limb strength training proposed in this study presents little difference in relation to the traditional mode of strength training in the optimization of maximum strength; however, it is more directed to soccer demand, and it can promote a better motor coordination to the athletes, besides optimizing the soccer sport level and making the athletes have more advantages in the field. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Physical qualities and body composition predictors of running performance in national level women's official soccer matches.

The purpose of the study was to (1) determine match running performance, anthropometry and various physical qualities of national level women soccer players and (2) identify key physical qualities and anthropometric predictors of match running profile during a competitive season. Twenty-five national level Finnish soccer players participated in the study. Players performed countermovement jump, loaded squat jumps, 30-meter sprint, maximum isokinetic knee flexor and extensor contractions, an incremental treadmill test and underwent body composition assessment in the lab. Match running performance was analyzed from 115 match observations during competitive league matches over 11 weeks after the laboratory tests. Pearson's correlation was used to determine bivariate relationships between match running variables and physical qualities and anthropometric variables. Identified significant bivariate relationships were then entered into multiple regression analyses to identify the best predictors of match running performance. Physical qualities and anthropometric variables predicted 65% of very high-intensity (VHIR) (> 19 km/h) and 63% of high-intensity (HIR) (13-19 km/h) running distances covered during matches, but only 22% of low-intensity (LIR) and 43% of total distances. Body fat percentage and high-speed knee flexor concentric strength were the most important predictors to VHIR and HIR while aerobic capacity-related variables were most important predictors to LIR and total distance. Physical qualities and anthropometry can predict a large portion of players' VHIR and HIR performance during matches in women's national level soccer. To increase player's VHIR and HIR distance, coaches could aim to develop players' high-speed (especially knee flexor concentric) strength and optimize player's body composition.

TREINAMENTO DE RESISTÊNCIA ASSOCIADO AO TREINO DE ATLETISMO

ABSTRACT Introduction Athletics has high requirements for resistance and strength. Therefore, more and more researchers are focusing on improving these athletes’ endurance and muscular strength, prioritizing their sports performance. Objective Explore methods of adding resistance to conventional training to increase performance and muscle strength in track and field. Methods Volunteers in the experiment and control groups were randomly assigned. Both groups received 10 weeks of physical training. The experimental group used a 10-meter lap run on the track, with squats, left and right-side squat jumps, fast bow squats, fast squats, fast trot runs, and lower limb lifting activities. The control group used only running in their conventional training. Results Significant differences were found in the blood lactate test rates of the experimental groups. The maximum heart rate and heart rate at 3 minutes after the end of the test decreased, the recovery rate increased, the number of continuous squats and average squats in one minute increased significantly, the 8RM squat, 1RM squat, vertical jump. Long jump had very significant differences, including the vertical stiffness in the drop jump. Conclusion The endurance and muscle strength of track and field athletes had positive impacts through the experimental training presented. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Squat Jump Goal Keeper and Field Player Biomechanics Analysis

Squat Jump Goal Keeper and Field Player Biomechanics Analysis

EFEITO DO TREINAMENTO COM PESOS SOBRE A FORÇA DOS MEMBROS INFERIORES EM ATLETAS DE ARTES MARCIAIS

ABSTRACT Introduction: It is believed that weight training on the lower limbs in martial arts athletes can contribute to a better performance of the whiplash, a specific movement that encompasses pliometry, balance and strength. Objective: Study the effects of weight training on lower limb strength in martial arts athletes when performing the whiplash. Methods: A controlled experiment was conducted involving 100 martial arts athletes, randomly divided into two groups of characteristics without statically relevant differences. The experimental group received weight training, while the control group received no additional intervention to their daily training. Results: The vertical jump in the experimental group increased from 31.24 ± 6.65 cm to 36.00 ± 9.62 cm; the vertical jump in horizontal standing position increased from 195.49 ± 4.16 cm to 196.51 ± 7.49 cm; the approach vertical jump varied from 32.94 ± 9.21 cm to 37.60 ± 11. 50 cm; the jump from the local half squat position was from 34.55 ± 6.40 cm to 40.30 ± 8.14 cm; the maximum force of a squat with weights was from 140.81 ± 10.05 kg to 142.06 ± 10.23 kg; the maximum number of supine leg raises in one minute increased from 43.43 ± 6.15 to 48.05 ± 7.29. Conclusion: Weight training positively influenced lower limb strength in martial arts athletes, whiplash performance was elevated. Weight training is recommended in the daily training of martial arts athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Squatting Facets and Trochlear Extensions of Talus Bone in Indian Population

Introduction: The talus is a tarsal bone articulated with the tibia, fibula, navicular, and calcaneus bones to form supratalar, pretalar, and subtalar joints, respectively. A squatting facet is a kind of anomaly that forms on the surfaces where the tibia and talus articulate. The squatting facet states the daily activities and living style of society. Squatting is described as the hyperflexion of the hip and the knee and the movement of hyperdorsiflexion between the leg and the ankle. Materials and Methods: In the present cross-sectional study, 600 dry adult human tali were taken from the osteology laboratory in the Department of Anatomy, King George's Medical University, UP, Lucknow. Each talus was examined for the presence of various patterns of articular facets on the neck of the talus and extensions of its trochlear surface. Ethical clearance was obtained from the Institutional Ethics Committee, King George's Medical University, Lucknow, as reference code: 121 ECMIIA/P3. Results: In our study, we observed that the lateral, medial, and combined squatting faces are 282 (47.64%), 49 (8.28%), and 22 (3.72%), respectively. Lateral, medial, and continuous trochlear extensions are 126 (21.12%), 120 (20.58%), and 31 (5.36%), respectively, in the Indian population. Conclusion: Modifications of the neck of the talus (squatting facets and trochlear extensions) are the result of prolonged squatting positions, which is a common habit of the Indian population, and incidences of these variations can be used as an anthropological marker for racial and regional differentiation of unidentified bones.

Association between the dry-land strength & power and the kick start kinetics in elite male and female swimmers

ABSTRACT The aim of this research was to determine the association between dry-land exercises and the start kinetics in elite swimmers. Fourteen swimmers (eight males and six females) included in a national team took part in this study. A fixed smith-machine was used to measure the maximal full squat strength (Smax). The height of squat (SJ) and countermovement (CMJ) jumps were collected with a contact mat. The ground reaction force of the kick starts in the three-dimensional axis (Fz horizontal; Fy, vertical; Fx, lateral) was obtained by an instrumented force plate in the starting block. Overall, the Smax showed a high and significant association with Fz (r = 0.60) and Fy (r = 0.87). Moderate and significant associations were found between Fy and SJ (r = 0.51) and CMJ (r = 0.57). While Smax in males showed high association with Fy (r = 0.77), the Smax for females showed greater association with Fz (r = 0.84). As conclusion, the full back squat seems to be the dry-land exercise with higher association with the kick start kinetics. While in males the full squat defines better the vertical component, for females it defines the horizontal one.

Speed, Agility and Power Potential of Young Basketball Players

Background. As basketball constantly evolves, physical performance becomes more and more important. Physical fitness assessments are the most reliable way to find out at what level a basketball player is prepared to perform. Therefore, the main aim of this research was to determine if the speed, agility and power of under-16-year-old (U16) basketball players is related to their playing positions. Methods. The study included (n = 40) young basketball (aged 14.99 ± 0.84 years) players. The variables included height, body mass, body mass index (BMI), fat-free mass (FFM), the percentage of body fat (BF%), the counter movement jump (CMJ), counter movement jump with free arms (CMJ free arms), squat jump (SJ), 5m, 10m, 15m and 20m sprints, T-test, Illinois test and 505 test. Results. The results showed that centers are taller and heavier than other positions, while the speed, agility and power of forwards are greater than other positions. Conclusions. At the youth basketball level there are differences in anthropometric and physical fitness testing results between positions. This supports the fact that athletes may be more likely to be selected for a given position based on how their anthropometric and athletic abilities pair with the demands of a given position. Keywords: body composition; physical testing; playing position; performance.

Estimation and Comparison of Knee Joint Contact Forces During Heel Contact and Heel Rise Deep Squatting.

Increased knee flexion is required for deep squatting in the daily life of the non-western population as well as in many sports activities. The purpose of this study was to estimate as well as to compare knee joint contact forces during heel contact (HC) and heel rise (HR) deep squatting in 10 healthy young Indian participants. Kinematic data were captured using a 12-camera Motion Analysis system. Kinetic data were collected using two Kistler force plates. EMG of 6 lower limb muscles was monitored by Noraxon wireless EMG. OpenSim musculoskeletal model was customized to increase the maximum knee flexion capability of the existing model and knee joint contact forces were estimated. A significant difference in tibiofemoral (p < 0.001) as well as patellofemoral (p = 0.006) knee joint contact force was observed between HC and HR squatting. The resultant maximum tibiofemoral KJCF was 5.9 (± 0.54) times body weight (BW) and 5.3 (± 0.6) BW for the HC and HR, respectively. The resultant maximum patellofemoral KJCF was 7.8 (± 0.57) BW and 7.1 (± 0.73) BW for the HC and HR, respectively. The findings can provide implications for physiotherapists to design rehabilitation exercise protocols, exercise professionals, and the development of high flexion knee implants. The online version contains supplementary material available at 10.1007/s43465-022-00798-y.