Hip Flexion Range Research Articles

The Effectiveness of PNF Versus Static Stretching on Increasing Hip-Flexion Range of Motion.

Clinical Scenario: Stretching is applied for the purposes of injury prevention, increasing joint range of motion (ROM), and increasing muscle extensibility. Many researchers have investigated various methods and techniques to determine the most effective way to increase joint ROM and muscle extensibility. Despite the numerous studies conducted, controversy still remains within clinical practice and the literature regarding the best methods and techniques for stretching. Focused Clinical Question: Is proprioceptive neuromuscular facilitation (PNF) stretching more effective than static stretching for increasing hamstring muscle extensibility through increased hip ROM or increased knee extension angle (KEA) in a physically active population? Summary of Key Findings: Five studies met the inclusion criteria and were included. All 5 studies were randomized control trials examining mobility of the hamstring group. The studies measured hamstring ROM in a variety of ways. Three studies measured active KEA, 1 study measured passive KEA, and 1 study measured hip ROM via the single-leg raise test. Of the 5 studies, 1 study found greater improvements using PNF over static stretching for increasing hip flexion, and the remaining 4 studies found no significant difference between PNF stretching and static stretching in increasing muscle extensibility, active KEA, or hip ROM. Clinical Bottom Line: PNF stretching was not demonstrated to be more effective at increasing hamstring extensibility compared to static stretching. The literature reviewed suggests both are effective methods for increasing hip-flexion ROM. Strength of Recommendation: Using level 2 evidence and higher, the results show both static and PNF stretching effectively increase ROM; however, one does not appear to be more effective than the other.

2D VIDEO FEEDBACK IMPROVES LANDING TECHNIQUE IN ELITE FEMALE HANDBALL PLAYERS

BackgroundIn handball an anterior cruciate ligament injury often occurs during a jump shot landing. Video feedback is effective to improve landing although little is known about its influence in sport-specific...

Effect of Dry Needling on Thigh Muscle Strength and Hip Flexion in Elite Soccer Players.

Increase in muscle force, endurance, and flexibility is desired in elite athletes to improve performance and to avoid injuries, but it is often hindered by the occurrence of myofascial trigger points. Dry needling (DN) has been shown effective in eliminating myofascial trigger points. This randomized controlled study in 30 elite youth soccer players of a professional soccer Bundesliga Club investigated the effects of four weekly sessions of DN plus water pressure massage on thigh muscle force and range of motion of hip flexion. A group receiving placebo laser plus water pressure massage and a group with no intervention served as controls. Data were collected at baseline (M1), treatment end (M2), and 4 wk follow-up (M3). Furthermore, a 5-month muscle injury follow-up was performed. DN showed significant improvement of muscular endurance of knee extensors at M2 (P = 0.039) and M3 (P = 0.008) compared with M1 (M1:294.6 ± 15.4 N·m·s, M2:311 ± 25 N·m·s; M3:316.0 ± 28.6 N·m·s) and knee flexors at M2 compared with M1 (M1:163.5 ± 10.9 N·m·s, M2:188.5 ± 16.3 N·m·s) as well as hip flexion (M1: 81.5° ± 3.3°, M2:89.8° ± 2.8°; M3:91.8° ± 3.8°). Compared with placebo (3.8° ± 3.8°) and control (1.4° ± 2.9°), DN (10.3° ± 3.5°) showed a significant (P = 0.01 and P = 0.0002) effect at M3 compared with M1 on hip flexion; compared with nontreatment control (-10 ± 11.9 N·m), DN (5.2 ± 10.2 N·m) also significantly (P = 0.049) improved maximum force of knee extensors at M3 compared with M1. During the rest of the season, muscle injuries were less frequent in the DN group compared with the control group. DN showed a significant effect on muscular endurance and hip flexion range of motion that persisted 4 wk posttreatment. Compared with placebo, it showed a significant effect on hip flexion that persisted 4 wk posttreatment, and compared with nonintervention control, it showed a significant effect on maximum force of knee extensors 4 wk posttreatment in elite soccer players.

How well do lower femoral neck-shaft angles match native anatomies in patients with deformed coxa vara hip? A retrospective chart review

Background and objectives: Patients undergoing total hip arthroplasty (THA) may have femoral deformities classified as either coxa vara, coxa valga, or physiologic. Understanding patients' anatomies is of importance for surgeons in an effort to tailor not only surgical approach, but also implant selection, and ultimately ensure optimal outcomes. The goal of the present study is to determine the efficacy of implanting a lower neck shaft angle (NSA) femoral stem in patients with coxa vara deformities and determine short-term clinical outcomes. Design: A retrospective chart review study. Methods: The study took place at The Texas Center for Joint Replacement in Plano, Texas. Two patient groups, clinical outcomes group and EOS group, were used for this study. The clinical outcomes group contained 55 patients who had undergone primary THA surgery from June 2013 to June 2015 by the senior author. The EOS group contained 36 patients who had undergone primary THA, and completed both preoperative and postoperative biplanar X-rays (low dose imaging device EOS) to obtain three-dimensional reconstructions of the skeletal system from October 2015 to November 2016. Operations were performed in all hips through the anterior supine intermuscular approach utilizing a 123° NSA femoral stem, which was lower than the NSA (133°) found in standard femoral stem implants. Outcome measures: Pre- and postoperative Harris hip scores used to assess clinical outcomes following surgery. Pre- and postoperative femoral offset, NSA, and femur length determined by EOS. Results: In the EOS group, mean femoral offset decreased by 3.5 mm, from 41.08 mm preoperatively to 37.6 mm postoperatively. Mean femoral NSAs decreased by 0.02°, from 123.02° preoperatively to 123.00° postoperatively. Mean femur length decreased by 2.4mm, from 404.2 mm preoperatively to 401.8 mm postoperatively. In the clinical outcomes group, mean Harris hip scores rose from 47 preoperatively to 93 postoperatively. Hip flexion range of motion improved from 87.5° preoperatively to 98° postoperatively. Conclusion: The lower NSA femoral stem examined in this study was proven to accurately restore NSA by 0.03°, femoral offset by 3.47 mm, and femur length by 2 mm, all within clinically documented satisfactory ranges without no revisions, suggesting excellent clinical outcomes in patients with coxa vara hip deformities. THA surgeons may consider utilizing femoral stems with a lower NSA in an effort to adequately restore hip function in patients with coxa vara hip deformities. Trial registration: This is a retrospective chart review study, therefore registration was not required.

Subcapital reorientation for moderate and severe slipped capital femoral epiphysis: early results of Ain Shams University Hospitals

Background Subcapital reorientation for severe slipped capital femoral epiphysis offers the double benefit of immediate restoration of range of motion (ROM), limb length discrepancy (LLD), and long-term hip preservation from premature osteoarthrosis. Patients and methods Modified Dunn’s technique through safe surgical hip dislocation was performed in 12 adolescents who presented with moderate-to-severe slipped capital femoral epiphysis. There were 10 males and only two females, with a mean age of 15 years. The mean Southwick’s slip angle was 47°. Only two slips were clinically unstable. Results After a mean follow-up of 23 months, the mean α angle measured 37°, and the mean slip angle decreased to 4.7°. The mean hip flexion range was 104°; the mean internal rotation in flexion was 33°; and the mean external rotation in flexion was 34°. The mean Harris hip score at the latest follow-up was 99.6. None of the cases developed chondrolysis or osteonecrosis. Conclusion It has been a long-standing orthopedic myth, believed by many surgeons, that the capital epiphysis cannot be realigned for fear of avascular necrosis. On the basis of the present study, we believe that subcapital reorientation through safe surgical hip dislocation approach restores close to normal the proximal femoral anatomy, and thus, presumably, would offer good long-term outcomes for a condition that can have serious lifelong consequences on young adults.

Long Term Effects of Various Manual Techniques on Hip Flexion Range of Motion in Collegiate Players with Hamstring Tightness: A Randomized Control Trial

Hamstring strain is a common injury in sports like football, basketball, kabaddi and hockey which involve sprinting, kicking, high-speed skilled movements and jumping actions. It is a frustrating injury well known to physiotherapists, coaches, and athletes due to its prolonged periods of recovery, acute functional loss of performance, and subsequent increase of reoccurrence in athletes. Though there has been many studies comparing the effectiveness of the different stretching techniques to improve hamstring tightness but there is no evidence of follow-up to check whether the effect of the stretch persists

Correlation Between Ankle-Dorsiflexion and Hip-Flexion Range of Motion and the Functional Movement Screen Hurdle-Step Score.

Functional movement screening (FMS) has been gaining popularity in the fields of sports medicine and performance. Currently, limited research has examined whether FMS screening that identifies low FMS scores is attributed primarily to limits in range of motion (ROM). To compare scores from the FMS hurdle-step movement with ROM measurements for ankle dorsiflexion and hip flexion (HF). Correlational research design. Sports medicine research laboratory. 20 healthy active male (age 21.2 ± 2.4 y, weight 77.8 ± 10.2 kg, height 180.8 ± 6.8 cm) and 20 healthy active female (21.3 ± 2.0 y, 67.3 ± 8.9 kg, 167.4 ± 6.6 cm) volunteers. All 40 participants completed 3 trials of the hurdle-step exercise bilaterally and goniometric ROM measurements for active ankle dorsiflexion and HF. Correlations were determined between ROM and FMS scores for right and left legs. In addition, mean data were compared between FMS scores, gender, and dominant and nondominant limbs. There were no significant correlations present when all participants were grouped. However, when separated by gender significant correlations were identified. There was a weak correlation with HF and both hurdle-step (HS) and average hurdle-step (AHS) scores on both left (r = .536, P = .015 and r = .512, P = .012) and right (r = .445, P = .049 and r = .565, P = .009) legs for women. For men, there was a poor negative correlation of HF and both HS and AHS on the left leg (r = -.452, P = .045 and r = .451, P = .046). Our findings suggest that although hip and ankle ROMs do not have a strong relationship with FMS hurdle-step scores, they are a contributing factor. More research should be conducted to identify other biomechanical factors that contribute to individual FMS test scores.

Innovative Video Feedback on Jump Landing Improves Landing Technique in Males.

Video feedback may be a powerful tool to change biomechanical landing patterns associated with anterior cruciate ligament (ACL) injury risk. This study investigated the effect of video feedback on drop vertical jump (DVJ) landing strategies in team sport athletes. 59 athletes were assigned to a video feedback (VI) or control (CTRL) group. A pretest, 2 training sessions and a posttest were conducted. In both training sessions, video feedback, consisting of a video of the athlete's contour superimposed onto an expert's contour performing the DVJ landing task, was provided to the VI group; the CTRL group did not receive feedback. Outcomes included: kinematics and kinetics at peak knee valgus/varus moment during pre- and posttest and percentage overlap of expert and athlete during the training sessions. At posttest, males in the VI group showed greater hip flexion angles (p=0.001) and range of motion (p<0.001), smaller vertical ground reaction force, and smaller ankle dorsiflexion moment (p<0.001) compared to pretest. At posttest, males in the VI group demonstrated smaller vertical ground reaction force (p=0.031) and ankle dorsiflexion moment (p=0.001) compared to males in the CTRL group. The VI group increased percentage overlap with the expert during training sessions and from start of the first to the end of the second training session (p<0.001). Overall, video feedback was effective to modify landing strategies favorably in males. While females imitated the expert model, their landing strategy did not change significantly. While Females may need additional (verbal) feedback to benefit from video feedback.

Effects of a combined inversion and plantarflexion surface on knee and hip kinematics during landing

Although landing in a plantarflexion and inversion position is a well-known characteristic of lateral ankle sprains, the associated kinematics of the knee and hip is largely unknown. Therefore, the purpose of this study was to examine the changes in knee and hip kinematics during landings on an altered landing surface of combined plantarflexion and inversion. Participants performed five drop landings from 30 cm onto a trapdoor platform in three different conditions: flat landing surface, 25° inversion, or a combined 25° plantarflexion and 25° inversion. Kinematic data were collected using a seven camera motion capture system. A 2 × 3 (leg × surface) repeated measures ANOVA was used for statistical analysis. The combined surface showed decreased knee and hip flexion range of motion (ROM) and increased knee abduction ROM (p < 0.05). The altered landing surface creates a stiff landing pattern where reductions in sagittal plane motion are transferred to the frontal plane, resulting in increased knee abduction. A stiff landing pattern is frequently related to increased risk of anterior cruciate ligament injury. It may be beneficial for athletes at risk to train for alternate methods of increasing their sagittal plane motion of the knee and hip with active knee or trunk flexion.

A Comparison of Two Thermal Modalities on Passive Hip Flexion Range of Motion.

A Comparison of Two Thermal Modalities on Passive Hip Flexion Range of Motion.

Influence of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres

ABSTRACTLimb dominance theory suggests that females tend to be more one-leg dominant and exhibit greater kinematic and kinetic leg asymmetries than their male counterparts, contributing to the increased risk of anterior cruciate ligament injury among female athletes. Thus, the purpose of this study was to examine the influences of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres. Twenty-one women and 21 men completed land-and-cut manoeuvres on their dominant limb as well as their nondominant limb. Three-dimensional kinematics and kinetics were calculated bilaterally for the entire stance phase of the manoeuvre. Women performed land-and-cut manoeuvres with altered hip motions and loads as well as greater knee abduction at touchdown compared to men. Dominant limb land-and-cut manoeuvres where characterised by decreased hip flexion at touchdown as well as decreased hip flexion and adduction range of motion compared to nondominant land-and-cuts regardless of sex. The observed sex differences are consistent with previous research regarding mechanisms underlying the sex disparity in anterior cruciate ligament injury rates. However, observed differences regarding limb dominances appear somewhat arbitrary and did not suggest that the dominant or nondominant limb would be at increased risk of anterior cruciate ligament injury.

Does High Hip Center Decrease Range of Motion in Total Hip Arthroplasty? A Computer Simulation Study

BackgroundHigh placement of a cementless acetabular cup is often required to have sufficient bone coverage in hip dysplasia. We examined whether a high hip center decreases the postoperative range of motion (ROM) in total hip arthroplasty. MethodsUsing a computer software, ROM and bone coverage were examined in 32 patients with unilateral osteoarthritis of the hip with Crowe type II or III hip dysplasia. The cup was placed at the anatomic hip center and moved vertically in 5-mm increments. Vertical center of rotation (V-COR) was defined as the distance from the head center to the interteardrop line. The required ROM was defined as flexion ≥110°, internal rotation (IR) at 90° flexion ≥30°, extension ≥30°, and external rotation ≥30°. We determined the V-COR to satisfy the required ROM and cup center-edge angle (Cup-CE) ≥0°. ResultsOnly 40.6% of the patients satisfied Cup-CE ≥0° at the anatomic hip center. Bone coverage increased with the peak at 30, 35 mm of V-COR (90.6% satisfied Cup-CE ≥0°) and decreased at ≥40 mm. Higher V-COR resulted in lower range of flexion and IR, but increased the range of extension and external rotation. The cutoff value from the receiver-operating characteristic curve for both flexion and IR was a V-COR of 35 mm. ConclusionThe higher hip center gained more bone coverage but decreased the range of hip flexion and IR. Acceptable V-COR in hip dysplasia was around 35 mm, about 20 mm above the true hip center, in terms of ROM.

Influence of Topical Analgesic Cream on Passive Hip Flexion Range of Motion, Sensation of Pressure, and Temperature

Influence of Topical Analgesic Cream on Passive Hip Flexion Range of Motion, Sensation of Pressure, and Temperature

Effect of Ankle Positioning During Hamstring Stretches for Improving Straight Leg Hip Flexion Motion.

To compare the effects of stretching the hamstrings with the ankle in either a plantar-flexed (PF) or dorsiflexed (DF) position for improving straight leg hip flexion range of motion (ROM) over a 4-week period. Randomized, single-blinded, pretest, posttest design. Athletic training facility. Each limb of 34 asymptomatic individuals (15 males, 19 females) was randomly assigned to one of the 3 groups. Twenty-four limbs received hamstring stretches with the ankle in DF, 24 limbs received hamstring stretches with the ankle in PF, and 20 limbs received no stretch (control). Ankle position (PF, DF) during hamstring stretching. We measured pretest and posttest passive straight leg hip flexion ROM with the test ankle in a neutral position. For the intervention groups, the test limb was passively stretched with the ankle held in end range DF or PF for their respective group. Each stretch was held for 30 seconds for a total of 3 applications. Two treatment sessions were completed per week for a total of 4 weeks. The control limbs received no stretching during the 4-week period. We conducted 1-way analyses of covariance to determine significant changes in ROM between groups (P < 0.05). There was no significant difference between treatment groups (P = 0.90), but a significant difference was found for both the PF (P = 0.04) and DF (P = 0.01) groups when compared with the control group. Our findings indicate that both stretching the hamstrings in either PF or DF improve straight leg hip ROM compared with a control group. The results of this study should be considered by clinicians when determining the optimal stretching techniques aimed at increasing hamstring length.

The effects of neurodynamic straight leg raise treatment duration on range of hip flexion and protective muscle activity at P1

Study design: Randomized, single blind, same subject crossover trial.Objectives: To compare the effects of two neurodynamic treatment doses on range of hip flexion (ROM HF) and electromyographic (EMG) activity of semitendinosus, at first onset of pain (P1).Methods: A total of 26 healthy participants without low back or leg pain received each treatment in a random order with at least 48 hours between sessions. Baseline ROM HF and EMG magnitude of semitendinosus at P1 were collected. Subjects then received either 361 or 362 minutes of oscillating end of range (grade IVz) straight leg raise (SLR) neurodynamic treatment and were re-assessed for baseline measures.Results: There was no significant difference between groups in EMG magnitude (P50.190) and ROM HF (P50.739) at P1. There was also no significant difference within groups in EMG magnitude at P1 (P50.182); however, there was a significant improvement in ROM HF at P1 in both groups compared to baseline readings (P50.000), with increases of 6.7u and 5.1u for the 361- and 362-minute groups, respectively.Conclusion: Findings indicate that 362 minutes of oscillating grade IVz SLR neurodynamic treatment has no additional benefit over 361 minute, on ROM HF or EMG magnitude of semitendinosus at P1. Using an oscillating SLR treatment may, however, help to increase pain-free ROM HF, although further studies are necessary to confirm this.

Comparison of effects of static, proprioceptive neuromuscular facilitation and Mulligan stretching on hip flexion range of motion: a randomized controlled trial.

The aim of this study was to compare the effects of static stretching, proprioceptive neuromuscular facilitation (PNF) stretching and Mulligan technique on hip flexion range of motion (ROM) in subjects with bilateral hamstring tightness. A total of 40 students (mean age: 21.5±1.3 years, mean body height: 172.8±8.2 cm, mean body mass index: 21.9±3.0 kg · m-2) with bilateral hamstring tightness were enrolled in this randomized trial, of whom 26 completed the study. Subjects were divided into 4 groups performing (I) typical static stretching, (II) PNF stretching, (III) Mulligan traction straight leg raise (TSLR) technique, (IV) no intervention. Hip flexion ROM was measured using a digital goniometer with the passive straight leg raise test before and after 4 weeks by two physiotherapists blinded to the groups. 52 extremities of 26 subjects were analyzed. Hip flexion ROM increased in all three intervention groups (p<0.05) but not in the no-intervention group after 4 weeks. A statistically significant change in initial–final assessment differences of hip flexion ROM was found between groups (p<0.001) in favour of PNF stretching and Mulligan TSLR technique in comparison to typical static stretching (p=0.016 and p=0.02, respectively). No significant difference was found between Mulligan TSLR technique and PNF stretching (p=0.920). The initial–final assessment difference of hip flexion ROM was similar in typical static stretching and no intervention (p=0.491). A 4-week stretching intervention is beneficial for increasing hip flexion ROM in bilateral hamstring tightness. However, PNF stretching and Mulligan TSLR technique are superior to typical static stretching. These two interventions can be alternatively used for stretching in hamstring tightness.

Breathing Techniques Affect Female but Not Male Hip Flexion Range of Motion.

Two protocols were undertaken to help clarify the effects of breathing techniques on hamstrings (hip flexion) range of motion (ROM). The protocols examined effects of breathing conditions on ROM and trunk muscle activity. Protocol 1: Thirty recreationally active participants (15 male, 15 female, 20-25 years) were monitored for changes in single-leg raise (SLR) ROM with 7 breathing conditions before or during a passive supine SLR stretch. Breathing conditions included prestretch inhale, prestretch exhale, inhale-during stretch, exhale-during stretch, neutral, hyperventilation, and hypoventilation before stretch. Protocol 2: Eighteen recreationally active participants (9 male, 9 female, 20-25 years) were monitored for electromyographic (EMG) activity of the rectus abdominus, external obliques, lower abdominal stabilizers, and lower erector spinae while performing the 7 breathing conditions before or during a passive SLR stretch. Control exhibited less ROM (p = 0.008) than the prestretch inhale (7.7%), inhale-during stretch (10.9%), and hypoventilation (11.2%) conditions with females. Protocol 3: Greater overall muscle activity in the prestretch exhale condition was found compared with inhale-during stretch (43.1%↓; p = 0.029) and hypoventilation (51.2%↓; p = 0.049) conditions. As the inhale-during stretch and hypoventilation conditions produced the lowest levels of muscle activity for both sexes and the highest ROM for the females, it can be assumed that both mechanical and neural factors affect female SLR ROM. Lesser male ROM might be attributed to anatomical differences such as greater joint stiffness. The breathing techniques may have affected intra-abdominal pressure, trunk muscle cocontractions, and sympathetic neural activity to enhance female ROM.

Running Mechanics and Variability with Aging.

As the elderly population in the United States continues to grow, issues related to maintenance of health become increasingly important. Physical activity has positive benefits for healthy aging. Running, a popular form of exercise, is associated with the risk of developing injury, especially in older runners. Initial differences between older and younger runners have been observed, but these were observed without consideration of other differences between groups, such as running mileage. This study aims to compare running mechanics and lower-extremity coordination variability in matched groups of healthy younger and healthy older runners. Three-dimensional kinetics and kinematics were collected while 14 older adults (45-65 yr) and younger adults (18-35 yr) ran overground at 3.5 m·s. Knee, ankle, and hip joint angles and moments were determined. Discrete measures at foot strike (maximum and minimum) were determined and compared between groups. Segment angles during stance were utilized to calculate segment coordination variability between pelvis and thigh, thigh and shank, and shank and foot, using a modified vector coding technique. Knee and ankle joint angles were similar between groups (P > 0.05). Older runners had greater hip range of motion (P = 0.01) and peak hip flexion (P = 0.001) at a more extended hip position than younger runners. Older runners had smaller ankle plantarflexion moment (P = 0.04) and hip rotational moment (P = 0.005) than younger runners. There were no between-group differences in any of the variability measures (P > 0.05). Runners appear to maintain movement patterns and variability during running with increasing age, indicating that running itself may be contributing to maintenance of health among older runners in the current study.

Physiological factors contributing to mobility loss over 9 years of follow-up—results from the InCHIANTI study.

Mobility is an essential aspect of everyday life and enables autonomy and participation. Although many risk factors for mobility loss have been previously described, their relative importance and independent contributions to the long-term risk of losing mobility have not been well defined. This study is based on 1,013 men and women aged ≥65 years enrolled in 1998-2000 and followed for 9 years through 2007-2008 in the population-based InCHIANTI (Invecchiare in Chianti, aging in the Chianti area) study. We considered 44 different measures assessed at baseline to explore six subsystems: (i) central nervous system, (ii) peripheral nervous system, (iii) muscles, (iv) bone and joints, (v) energy production and delivery, and (vi) perceptual system. The outcome was incident mobility loss defined as self-report of inability to walk 400 m or climb and descend 10 steps without help from another person. Random survival forest analysis was used to rank the candidate predictors by their importance. The most important physiological markers predicting mobility loss that emerged from the random survival forest modeling were older age among women (81-95 vs 65-68 years, hazard ratio [HR] 9.60 [95% CI 3.35, 27.50]), weaker ankle dorsiflexion strength (lowest vs highest quintile, HR 5.25 [95% CI 2.35, 11.72]), low hip flexion range of motion (lowest vs highest quintile, HR 2.30 [95% CI 1.20, 4.41]), presence of primitive reflexes (yes vs no, HR 1.47 [95% CI 1.03, 2.09]), and tremor (yes vs no, HR 1.91 [95% CI 1.18, 3.07]). Prevention of mobility loss with aging should focus on prevention and treatment of neuromuscular impairments.

Kinematic Patterns Associated with the Vertical Force Produced during the Eggbeater Kick

The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees.