scholarly journals Effects of a Curved Heel Shape in a Running Shoe on Biomechanical Variables and Comfort

2021 ◽  
Vol 11 (8) ◽  
pp. 3613
Author(s):  
Sihyun Ryu ◽  
Darren Stefanyshyn ◽  
Sejin Kong ◽  
Sang-Kyoon Park
Keyword(s):  
Lower Extremity ◽  
Ankle Joint ◽  
Reaction Force ◽  
Positive Influence ◽  
Vertical Ground Reaction Force ◽  
Lower Extremity Muscle ◽  
Heel Contact ◽  
Vertical Ground ◽  
Infrared Cameras ◽  
Muscle Activations

(1) Background: The purpose of this study was to investigate the effects of a rounded heel shoe (RHS) and rounded lateral heel shoe (RLHS) on impact and lower extremity stability as well as their relationships with comfort during running. (2) Methods: Twenty healthy male adults participated in the study. The data were collected using eight infrared cameras while participants were running at a speed of 2.7 m/s in three shoe conditions on an instrumented treadmill. (3) Results: The peak vertical ground reaction force (PVGRF) was statistically smaller for the RHS and RLHS compared with the normal shoes (NS) (p < 0.05). The range of motion of inversion–eversion at the ankle joint was statistically smaller for the RLHS compared with the NS and RHS (p < 0.05). Increased dorsiflexion of the ankle joint at heel contact was negatively related to the comfort of a running shoe, and increased dorsi-plantarflexion ROM was positively related to comfort. (4) Conclusions: Based on these results, a curved heel shape of a running shoe may provide a positive influence on the biomechanical function and the comfort of running shoes. Future study, including measurements of lower extremity muscle activations and long-term comfort, would be beneficial to help validate current findings and develop further applications.

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.

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 An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
AmirAli Jafarnezhadgero ◽  
Elahe Mamashli ◽  
Urs Granacher
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Exercise Program ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Significant Group ◽  
Heel Contact ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Post Hoc

BackgroundThe prevalence of diabetes worldwide is predicted to increase from 2.8% in 2000 to 4.4% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility.ObjectiveWe aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO2max), ground reaction forces, and muscle activities during walking in patients with moderate DN.MethodsSixty male and female individuals aged 45–65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40–55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO2max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s.ResultsNo statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO2max (p &lt; 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p &lt; 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001–0.037; d = 0.56–1.53). For IG, post-hoc analyses showed decreases in peak lateral (p &lt; 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p &lt; 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001–0.044; d = 0.54–0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p &lt; 0.001; d = 1.28).ConclusionsThis study demonstrated that an endurance-dominated exercise program has the potential to improve VO2max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics.

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.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

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