Bilateral Squatting Mechanics Are Associated With Landing Mechanics in Anterior Cruciate Ligament Reconstruction Patients

2021 ◽  
pp. 036354652110237
Author(s):  
Alexander T. Peebles ◽  
Blaise Williams ◽  
Robin M. Queen
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Knee Extension ◽  
Abduction Angle ◽  
Return To Sports ◽  
Vertical Ground Reaction Force ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Ground

Background: Proper lower extremity biomechanics during bilateral landing is important for reducing injury risk in athletes returning to sports after anterior cruciate ligament reconstruction (ACLR). Although landing is a quick ballistic movement that is difficult to modify, squatting is a slower cyclic movement that is ideal for motor learning. Hypothesis: There is a relationship between lower extremity biomechanics during bilateral landing and bilateral squatting in patients with an ACLR. Study Design: Descriptive laboratory study. Methods: A total of 41 patients after a unilateral ACLR (24 men, 17 women; 5.9 ± 1.4 months after ACLR) completed 15 unweighted bilateral squats and 10 bilateral stop-jumps. Three-dimensional lower extremity kinematics and kinetics were collected, and peak knee abduction angle, knee abduction/adduction range of motion, peak vertical ground-reaction force limb symmetry index (LSI), vertical ground-reaction force impulse LSI, and peak knee extension moment LSI were computed during the descending phase of the squatting and landing tasks. Wilcoxon signed-rank tests were used to compare each outcome between limbs, and Spearman correlations were used to compare outcomes between the squatting and landing tasks. Results: The peak vertical ground reaction force, the vertical ground reaction force impulse, and the peak knee extension moment were reduced in the surgical (Sx) limb relative to the nonsurgical (NSx) limb during both the squatting and landing tasks ( P < .001). The relationship between squatting and landing tasks was strong for the peak knee abduction angle ( R = 0.697-0.737; P < .001); moderate for the frontal plane knee range of motion (NSx: R = 0.366, P = .019; Sx: R = 0.418, P = 0.007), the peak knee extension moment LSI ( R = 0.573; P < .001), the vertical ground reaction force impulse LSI ( R = 0.382; P < .014); and weak for the peak vertical ground reaction force LSI ( R = 0.323; P = .039). Conclusion: Patients who have undergone an ACLR continue to offload their surgical limb during both squatting and landing. Additionally, there is a relationship between movement deficits during squatting and movement deficits during landing in patients with an ACLR preparing to return to sports. Clinical Relevance: As movement deficits during squatting and landing were related before return to sports, this study suggests that interventional approaches to improve squatting biomechanics may translate to improved landing biomechanics in patients with an ACLR.

Effects of Toe Direction on Biomechanics of Trunk, Pelvis, and Lower-Extremity During Single-Leg Drop Landing

2020 ◽  
Vol 29 (8) ◽  
pp. 1069-1074
Author(s):  
Aiko Sakurai ◽  
Kengo Harato ◽  
Yutaro Morishige ◽  
Shu Kobayashi ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Abduction Angle ◽  
Vertical Ground Reaction Force ◽  
Knee Ligament ◽  
Drop Landing ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Ground

Context: Toe direction is an important factor affecting knee biomechanics during various movements. However, it is still unknown whether toe direction will affect trunk and pelvic movements. Objective: To examine and clarify the effects of toe directions on biomechanics of trunk and pelvis as well as lower-extremities during single-leg drop landing (SLDL). Design: Descriptive laboratory study. Setting: Research laboratory. Participants: A total of 27 male recreational-level athletes. Intervention(s): Subjects performed SLDL under 3 different toe directions, including 0° (toe neutral), 20° (toe-in [TI]), and −20° (toe-out). SLDL was captured using a motion analysis system. Nondominant leg (27 left) was chosen for the analysis. Main Outcome Measures: Peak values of kinematic and kinetic parameters during landing phase were assessed. In addition, those parameters at the timing of peak vertical ground reaction force were also assessed. The data were statistically compared among 3 different toe directions using 1-way repeated measures of analysis of variance or Friedman χ2 r test. Results: Peak knee abduction angle and moment in TI were significantly larger than in toe neutral and toe-out (P < .001). Moreover, peak greater anterior inclination, greater inclination, and rotation of trunk and pelvis toward the nonlanding side were seen in TI (P < .001). At the timing of peak vertical ground reaction force, trunk inclined to the landing side with larger knee abduction angle in TI (P < .001). Conclusions: Several previous studies suggested that larger knee abduction angle and moment on landing side as well as trunk and pelvic inclinations during landing tasks were correlated with knee ligament injury. However, it is still unknown concerning the relationship between toe direction and trunk/pelvis movements during landing tasks. From the present study, TI during SLDL would strongly affect biomechanics of trunk and pelvis as well as knee joint, compared with toe neutral and toe-out.

scholarly journals Variable Heights Influence Lower Extremity Biomechanics and Reactive Strength Index during Drop Jump: An Experimental Study of Male High Jumpers

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zehao Tong ◽  
Feng Zhai ◽  
Hang Xu ◽  
Wenjia Chen ◽  
Jiesheng Cui
Keyword(s):  
Lower Extremity ◽  
Hip Joint ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Lower Limbs ◽  
Drop Height ◽  
Strength Index ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Biomechanical Parameters

Introduction. This study finds the lower limbs’ reactive strength index and biomechanical parameters on variable heights. Objective. This research aims to reveal the effects of drop height on lower limbs’ reactive strength index and biomechanical parameters. Methods. Two AMTI force platforms and Vicon motion capture system were used to collect kinematic and dynamic signals of the lower limbs. Results. The drop height had significant effects on peak vertical ground reaction force and peak vertical ground reaction force in the extension phase, lower limbs’ support moment, eccentric power of the hip joint, eccentric power of the knee joint, eccentric power of the ankle joint, and concentric power of the hip joint. The drop height had no significant effects on the reactive strength index. Reactive strength index (RSI) had no significant correlations with the personal best of high jumpers. The optimal loading height for the maximum reactive strength index was 0.45 m. Conclusion. The optimal loading height for the reactive strength index can be used for explosive power training and lower extremity injury prevention.

Single-Leg Drop Jump Biomechanics After Ankle or Knee Joint Cooling in Healthy Young Adults

2021 ◽  
pp. 1-8
Author(s):  
Jihong Park ◽  
Kyeongtak Song ◽  
Sae Yong Lee
Keyword(s):  
Angular Velocity ◽  
Knee Joint ◽  
Lower Extremity ◽  
Knee Flexion ◽  
Reaction Force ◽  
Drop Jump ◽  
Vertical Ground Reaction Force ◽  
Time To Peak ◽  
Peak Knee ◽  
Vertical Ground

Context: It is unclear if lower-extremity joint cooling alters biomechanics during a functional movement. Objective: To investigate the effects of unilateral lower-extremity cryotherapy on movement alterations during a single-leg drop jump. Design: A crossover design. Setting: Laboratory. Patients: Twenty healthy subjects (10 males and 10 females; 23 y, 169 cm, 66 kg). Intervention(s): Subjects completed a single-leg drop jump before and after a 20-minute ankle or knee joint cooling on the right leg, or control (seated without cooling) on 3 separate days. Main Outcome Measures: Time to peak knee flexion, vertical ground reaction force, lower-extremity joint angular velocity (sagittal plane only), and angle and moment (sagittal and frontal planes) in the involved leg over the entire ground contact (GC; from initial contact to jump-off) during the first landing. Time to peak knee flexion was compared using an analysis of variance; the rest of the outcome measures were analyzed using functional analyses of variance (P < .05). Results: Neither joint cooling condition changed the time to peak knee flexion (F2,95 = 0.73, P = .49). Ankle joint cooling reduced vertical ground reaction force (55 N at 4% of GC), knee joint angular velocity (44°/s during 5%–9% of GC), and knee varus moment (181 N·m during 18%–20% of GC). Knee joint cooling resulted in a reduction in knee joint angular velocity (24°/s during 37%–40% of GC) and hip adduction moment (151 N·m during 46%–48% of GC), and an increase in hip joint angular velocity (16°/s during 49%–53% of GC) and plantarflexion angle (1.5° during 11%–29% of GC). Conclusion: Resuming activity immediately after lower-extremity joint cooling does not seem to predispose an individual to injury during landing because altered mechanics are neither overlapping with the injury time period nor of sufficient magnitude to lead to an injury.

Early biomechanical outcome in patients with acetabular fractures treated using the pararectus approach: a gait and stair climb analysis study

2021 ◽  
Author(s):  
Andreas Brand ◽  
Christian von Rüden ◽  
Carina Probst ◽  
Lisa Wenzel ◽  
Peter Augat ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Acetabular Fractures ◽  
Functional Evaluation ◽  
Vertical Ground Reaction Force ◽  
Pararectus Approach ◽  
Vertical Ground ◽  
Hip Muscles ◽  
Hip Extension

Abstract Purpose Patients with surgically treated acetabular fractures using extensive dissection of hip muscles demonstrate an incomplete biomechanical recovery and limited joint mobility during movement. The purpose of this study was to evaluate the early biomechanical outcome in a series of patients with acetabular fractures treated using the less invasive anatomical pararectus approach. Methods Eight patients (48 ± 14 years, BMI 25.8 ± 3 kg/m2) were investigated 3.8 ± 1.3 months after surgery and compared to matched controls (49 ± 13 years, BMI 26 ± 2.8 kg/m2). Trunk and lower extremity kinematics and kinetics during gait and stair climb were calculated. SF-12 and the Merle d’Aubigné score were used for functional evaluation. Statistical analysis was conducted using Mann–Whitney test and Student’s t test. Effect sizes were calculated using Cohen’s d. Results No group differences for lower extremity kinematics during walking and stair climbing were found. During walking, patients showed significant reductions (p < 0.05) of the vertical ground reaction force (8%) and knee and hip extension moments (29 and 27%). Ipsilateral trunk lean was significantly increased by 3.1° during stair descend while reductions of vertical ground reaction force were found for stair ascend (7%) and descend (20%). Hip extension moment was significantly reduced during stair descend by 37%. Patients revealed acceptable SF-12 physical and mental component outcomes and a good rating for the Merle d’Aubigné score (15.9 ± 1.7). Conclusion Patients showed some biomechanical restrictions that can be related to residual deficits in weight bearing capacity and strength of the hip muscles. In contrast, an immediate recovery of mobility was achieved by preserving lower extremity and pelvic movement. Therefore, the pararectus approach can serve as a viable strategy in the surgical treatment of acetabular fractures. Clinical trial Trial registration number DRKS00011308, 11/14/2016, prospectively registered.

Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern

2000 ◽  
Vol 16 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Dorsey S. Williams ◽  
Irene S. McClay ◽  
Kurt T. Manal
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Three Dimensional ◽  
Vertical Ground Reaction Force ◽  
Running Performance ◽  
Vertical Ground ◽  
The Impact

Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.

scholarly journals Progression of Fatigue Modifies Primary Contributors to Ground Reaction Forces During Drop Landing

2021 ◽  
Vol 76 (1) ◽  
pp. 161-173
Author(s):  
Qiang Zhang ◽  
Mianfang Ruan ◽  
Navrag B. Singh ◽  
Lingyan Huang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Joint Stiffness ◽  
Knee Flexion Angle ◽  
Vertical Ground Reaction Force ◽  
Severe Fatigue ◽  
Peak Knee ◽  
Vertical Ground

Abstract Few studies have focused on the effect of fatigue severity on landing strategy. This study aimed to investigate the effect of fatigue progression on ground reaction force during landing. Eighteen participants performed a fatigue exercise protocol. Then participants performed drop landings at three levels of fatigue: no fatigue, medium fatigue, and severe fatigue. Multiple linear regression was conducted to identify the predictors of the peak vertical ground reaction force at each level of fatigue. Two-way ANOVAs were conducted to test the effect of fatigue on the vertical ground reaction force and the predictors. For the vertical ground reaction force, the knee joint stiffness and the knee angle at initial contact were the main predictors at no fatigue. The peak knee flexion angle and knee power were the main predictors at medium fatigue. However, the peak ankle plantarflexion moments became the main predictor at severe fatigue. The vertical ground reaction force decreased from no to medium fatigue (p = 0.001), and then increased from medium to severe fatigue (p = 0.034). The knee joint stiffness decreased from no to medium fatigue (p = 0.049), and then remained unchanged from medium to severe fatigue. The peak knee flexion angle increased from no to medium fatigue (p = 0.001), and then slightly decreased from medium to severe fatigue (p = 0.051). The results indicate that fatigue progression causes a transition from stiff to soft landing, and then to stiff landing. Participants used ankle joints more to control the landing intensity at severe fatigue.

Effects of Gender and Foot-Landing Techniques on Lower Extremity Kinematics during Drop-Jump Landings

2007 ◽  
Vol 23 (4) ◽  
pp. 289-299 ◽  
Author(s):  
Nelson Cortes ◽  
James Onate ◽  
João Abrantes ◽  
Linda Gagen ◽  
Elizabeth Dowling ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
The Self ◽  
Initial Contact ◽  
Knee Valgus ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Hip Flexion

The purpose of this study was to assess kinematic lower extremity motion patterns (hip flexion, knee flexion, knee valgus, and ankle dorsiflexion) during various foot-landing techniques (self-preferred, forefoot, and rear foot) between genders. 3-D kinematics were collected on 50 (25 male and 25 female) college-age recreational athletes selected from a sample of convenience. Separate repeated-measures ANOVAs were used to analyze each variable at three time instants (initial contact, peak vertical ground reaction force, and maximum knee flexion angle). There were no significant differences found between genders at the three instants for each variable. At initial contact, the forefoot technique (35.79° ± 11.78°) resulted in significantly (p= .001) less hip flexion than did the self-preferred (41.25° ± 12.89°) and rear foot (43.15° ± 11.77°) techniques. At peak vertical ground reaction force, the rear foot technique (26.77° ± 9.49°) presented significantly lower (p= .001) knee flexion angles as compared with forefoot (58.77° ± 20.00°) and self-preferred (54.21° ± 23.78°) techniques. A significant difference for knee valgus angles (p= .001) was also found between landing techniques at peak vertical ground reaction force. The self-preferred (4.12° ± 7.51°) and forefoot (4.97° ± 7.90°) techniques presented greater knee varus angles as compared with the rear foot technique (0.08° ± 6.52°). The rear foot technique created more ankle dorsiflexion and less knee flexion than did the other techniques. The lack of gender differences can mean that lower extremity injuries (e.g., ACL tears) may not be related solely to gender but may instead be associated with the landing technique used and, consequently, the way each individual absorbs jump-landing energy.

scholarly journals Associations Among Eccentric Hamstrings Strength, Hamstrings Stiffness, and Jump-Landing Biomechanics

2020 ◽  
Vol 55 (7) ◽  
pp. 717-723 ◽  
Author(s):  
Derek R. Dewig ◽  
Jonathan S. Goodwin ◽  
Brian G. Pietrosimone ◽  
J. Troy Blackburn
Keyword(s):  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Acl Injury ◽  
Ground Contact ◽  
Vertical Ground Reaction Force ◽  
Landing Biomechanics ◽  
Peak Knee ◽  
Acl Injury Risk ◽  
Vertical Ground

Context Anterior cruciate ligament (ACL) injury risk can be assessed from landing biomechanics. Greater hamstrings stiffness is associated with a landing-biomechanics profile consistent with less ACL loading but is difficult to assess in the clinical setting. Eccentric hamstrings strength can be easily evaluated by clinicians and may provide a surrogate measure for hamstrings stiffness. Objective To examine associations among eccentric hamstrings strength, hamstrings stiffness, and landing biomechanics linked to ACL injury risk. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants A total of 34 uninjured, physically active participants (22 women, 12 men; age = 20.2 ± 1.6 years, height = 171.5 ± 9.7 cm, mass = 67.1 ± 12.7 kg). Intervention(s) We collected eccentric hamstrings strength, active hamstrings stiffness, and double- and single-legged landing biomechanics during a single session. Main Outcome Measure(s) Bivariate associations were conducted between eccentric hamstrings strength and hamstrings stiffness, vertical ground reaction force, internal knee-extension moment, internal knee-varus moment, anterior tibial shear force, knee sagittal-plane angle at initial ground contact, peak knee-flexion angle, knee frontal-plane angle at initial ground contact, peak knee-valgus angle, and knee-flexion displacement using Pearson product moment correlations or Spearman rank-order correlations. Results We observed no association between hamstrings stiffness and eccentric hamstrings strength (r = 0.029, P = .44). We also found no association between hamstrings stiffness and landing biomechanics. However, greater peak eccentric strength was associated with less vertical ground reaction force in both the double-legged (r = −0.331, P = .03) and single-legged (r = −0.418, P = .01) landing conditions and with less internal knee-varus moment in the single-legged landing condition (r = −0.326, P = .04). Conclusions Eccentric hamstrings strength was associated with less vertical ground reaction force during both landing tasks and less internal knee-varus moment during the single-legged landing but was not an acceptable clinical estimate of active hamstrings stiffness.

Sign in / Sign up

Export Citation Format

Share Document