Lower-Extremity Biomechanics and Maintenance of Vertical-Jump Height During Prolonged Intermittent Exercise

2014 ◽  
Vol 23 (4) ◽  
pp. 319-329
Author(s):  
Randy J. Schmitz ◽  
John C. Cone ◽  
Timothy J. Copple ◽  
Robert A. Henson ◽  
Sandra J. Shultz
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Principal Components ◽  
Intermittent Exercise ◽  
Vertical Jump ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
Jump Height ◽  
Lower Extremity Biomechanics ◽  
Biomechanical Factors

Context:Potential biomechanical compensations allowing for maintenance of maximal explosive performance during prolonged intermittent exercise, with respect to the corresponding rise in injury rates during the later stages of exercise or competition, are relatively unknown.Objective:To identify lower-extremity countermovement-jump (CMJ) biomechanical factors using a principal-components approach and then examine how these factors changed during a 90-min intermittent-exercise protocol (IEP) while maintaining maximal jump height.Design:Mixed-model design.Setting:Laboratory.Participants:Fifty-nine intermittent-sport athletes (30 male, 29 female) participated in experimental and control conditions.Interventions:Before and after a dynamic warm-up and every 15 min during the 1st and 2nd halves of an individually prescribed 90-min IEP, participants were assessed on rating of perceived exertion, sprint/cut speed, and 3-dimensional CMJ biomechanics (experimental). On a separate day, the same measures were obtained every 15 min during 90 min of quiet rest (control).Main Outcome Measures:Univariate piecewise growth models analyzed progressive changes in CMJ performance and biomechanical factors extracted from a principal-components analysis of the individual biomechanical dependent variables.Results:While CMJ height was maintained during the 1st and 2nd halves, the body descended less and knee kinetic and energetic magnitudes decreased as the IEP progressed.Conclusions:The results indicate that vertical-jump performance is maintained along with progressive biomechanical changes commonly associated with decreased performance. A better understanding of lower-extremity biomechanics during explosive actions in response to IEP allows us to further develop and individualize performance training programs.

scholarly journals Magnitude, Frequency, and Accumulation: Workload Among Injured and Uninjured Youth Basketball Players

2021 ◽  
Vol 3 ◽  
Author(s):  
Lauren C. Benson ◽  
Oluwatoyosi B. A. Owoeye ◽  
Anu M. Räisänen ◽  
Carlyn Stilling ◽  
W. Brent Edwards ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Principal Components ◽  
Perceived Exertion ◽  
Achilles Tendinopathy ◽  
Rating Of Perceived Exertion ◽  
Lower Extremity Injury ◽  
Jump Height ◽  
Extremity Injury ◽  
Lower Extremity Injuries ◽  
Extremity Injuries

Overuse injuries are common in basketball. Wearable technology enables the workload to be monitored in sport settings. However, workload–injury models lack a biological basis both in the metrics recorded and how workload is accumulated. We introduce a new metric for monitoring workload: weighted jump height, where each jump height is weighted to represent the expected effect of the jump magnitude on damage to the tendon. The objectives of this study were to use principal components analysis to identify distinct modes of variation in all workload metrics accumulated over 1, 2, 3, and 4 weeks and to examine differences among the modes of variation in workload metrics between participants before the injury and uninjured participants. Forty-nine youth basketball players participated in their typical basketball practices and games, and lower extremity injuries were classified as patellar or Achilles tendinopathy, other overuse, or acute. An inertial measurement unit recorded the number and height of all jumps, and session rating of perceived exertion was recorded. The previous 1-, 2-, 3-, and 4-week workloads of jump count, jump height, weighted jump height, and session rating of perceived exertion were summed for each participant-week. Principal components analysis explained the variance in the accumulated workload variables. Using the retained principal components, the difference between the workload of injured participants in the week before the injury and the mean workload of uninjured participants was described for patellar or Achilles tendinopathy, overuse lower extremity injury, and any lower extremity injury. Participants with patellar or Achilles tendinopathy and overuse lower extremity injuries had a low workload magnitude for all variables in the 1, 2, 3, and 4 weeks before injury compared with the weeks before no injury. Participants with overuse lower extremity injuries and any lower extremity injury had a high previous 1-week workload for all variables along with a low previous 3- and 4-week jump count, jump height, and weighted jump height before injury compared with the weeks before no injury. Weighted jump height represents the cumulative damage experienced by tissues due to repetitive loads. Injured youth basketball athletes had a low previous 3- and 4-week workloads coupled with a high previous 1-week workload.

scholarly journals Lower Extremity Biomechanics During a Drop-Vertical Jump and Muscle Strength in Women With Patellofemoral Pain

2020 ◽  
Vol 55 (6) ◽  
pp. 615-622
Author(s):  
Andrea Baellow ◽  
Neal R. Glaviano ◽  
Jay Hertel ◽  
Susan A. Saliba
Keyword(s):  
Lower Extremity ◽  
Knee Flexion ◽  
Vertical Jump ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Trunk Flexion ◽  
Healthy Group ◽  
Lower Extremity Biomechanics ◽  
Hip Internal Rotation ◽  
Kinematics And Kinetics

Context Patellofemoral pain (PFP) is one of the most prevalent knee conditions observed in women. Current research suggests that individuals with PFP have altered muscle activity, kinematics, and kinetics during functional tasks. However, few authors have examined differences in lower extremity biomechanics in this population during the drop-vertical jump (DVJ). Objective To determine how lower extremity electromyography, kinematics, and kinetics during a DVJ and lower extremity isometric strength differed between women with and those without PFP. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants Fifteen healthy women (age = 20.23 ± 1.39 years, height = 169.32 ± 5.38 cm, mass = 67.73 ± 9.57 kg) and 15 women with PFP (age = 22.33 ± 3.49 years, height = 166.42 ± 6.01 cm, mass = 65.67 ± 13.75 kg). Intervention(s) Three trials of a DVJ. Main Outcome Measure(s) Surface electromyography, kinematics, and kinetics were collected simultaneously during a DVJ. Lower extremity strength was measured isometrically. Independent-samples t tests were performed to assess group differences. Results Normalized muscle activity in the vastus medialis (healthy group = 120.84 ± 80.73, PFP group = 235.84 ± 152.29), gluteus maximus (healthy group = 43.81 ± 65.63, PFP group = 13.37 ± 13.55), and biceps femoris (healthy group = 36.68 ± 62.71, PFP group = 11.04 ± 8.9) during the landing phase of the DVJ differed between groups. Compared with healthy women, those with PFP completed the DVJ with greater hip internal-rotation moment (0.04 ± 0.28 N/kg versus 0.06 ± 0.14 N/kg, respectively) and had decreased knee-flexion excursion (76.76° ± 7.50° versus PFP = 74.14° ± 19.85°, respectively); they took less time to reach peak trunk flexion (0.19 ± 0.01 seconds versus 0.19 ± 0.02 seconds, respectively) and lateral trunk flexion (0.12 ± 0.07 seconds versus 0.11 ± 0.04 seconds, respectively). Conclusions During the DVJ, women with PFP had increased hip internal-rotation moment and decreased knee-flexion excursion with less time to peak trunk flexion and lateral flexion. Muscle activation was increased in the vastus medialis but decreased in the gluteus maximus and biceps femoris. This suggests that altered motor-unit recruitment in the hip and thigh may result in changes in biomechanics during a DVJ that are often associated with an increased risk of injury.

scholarly journals Acute Effects of Midsole Bending Stiffness on Lower Extremity Biomechanics during Layup Jumps

2020 ◽  
Vol 10 (1) ◽  
pp. 397
Author(s):  
Zhiqiang Zhu ◽  
Weijie Fu ◽  
En Shao ◽  
Lu Li ◽  
Linjie Song ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ankle Joint ◽  
Jump Height ◽  
Acute Effects ◽  
Kinetic Chain ◽  
Joint Power ◽  
Joint Biomechanics ◽  
Reaction Forces ◽  
Lower Extremity Biomechanics ◽  
And Control

Purpose: This study aims to investigate the acute effects of shoe midsole stiffness on the joint biomechanics of the lower extremities during specific basketball movements. Methods: Thirty participants wearing stiff midsole shoes (SS) and control shoes (CS) performed layup jumps (LJs) while the kinematics and ground reaction forces were simultaneously collected via the Vicon motion capture system and Kistler force plates. Furthermore, the joint angles, range of motion (ROM), joint power, joint energy, and jump height were calculated. Results: No significant differences were observed between SS and CS conditions for both jump height and the metatarsophalangeal (MTP) joint biomechanics except that the minimum angular velocity of the MTP joint was significantly lower in SS the condition. However, the ROM in the ankle joint was significantly greater in the SS condition than in the CS condition (p < 0.05). Additionally, the maximum plantarflexion power, energy absorption (EA), and energy generation (EG) in the ankle joint were significantly greater in the SS condition than in the CS condition (p < 0.05). Compared with the CS condition, jump height in the SS condition did not increase. Conclusion: During a single LJ, the longitudinal midsole stiffness did not influence the jump height and MTP joint biomechanical patterns but significantly increased the maximum power, EA, and EG during the push-off phase of the ankle joint. These preliminary results indicate that wearing SS could change the ankle joint mechanical patterns by modulating the lower extremity kinetic chain, and may enhance muscle strength in the ankle.

scholarly journals Strength, Multijoint Coordination, and Sensorimotor Processing Are Independent Contributors to Overall Balance Ability

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Emily L. Lawrence ◽  
Guilherme M. Cesar ◽  
Martha R. Bromfield ◽  
Richard Peterson ◽  
Francisco J. Valero-Cuevas ◽  
...  
Keyword(s):  
Young Adults ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Vertical Jump ◽  
Lower Extremity Injury ◽  
Specific Information ◽  
Sensorimotor Processing ◽  
Multijoint Coordination ◽  
Balance Ability ◽  
Components Analysis

For young adults, balance is essential for participation in physical activities but is often disrupted following lower extremity injury. Clinical outcome measures such as single limb balance (SLB), Y-balance (YBT), and the single limb hop and balance (SLHB) tests are commonly used to quantify balance ability following injury. Given the varying demands across tasks, it is likely that such outcome measures provide useful, although task-specific, information. But the extent to which they are independent and contribute to understanding the multiple contributors to balance is not clear. Therefore, the purpose of this study was to investigate the associations among these measures as they relate to the different contributors to balance. Thirty-seven recreationally active young adults completed measures including Vertical Jump, YBT, SLB, SLHB, and the new Lower Extremity Dexterity test. Principal components analysis revealed that these outcome measures could be thought of as quantifying the strength, multijoint coordination, and sensorimotor processing contributors to balance. Our results challenge the practice of using a single outcome measure to quantify the naturally multidimensional mechanisms for everyday functions such as balance. This multidimensional approach to, and interpretation of, multiple contributors to balance may lead to more effective, specialized training and rehabilitation regimens.

Association Between Body Composition and Vertical Jump Performance in Female Collegiate Volleyball Athletes

2021 ◽  
Vol 9 (4) ◽  
pp. 43
Author(s):  
Lindsey Legg ◽  
Megan Rush ◽  
Jordan Rush ◽  
Stephanie McCoy ◽  
John C Garner ◽  
...  
Keyword(s):  
Body Composition ◽  
Lower Extremity ◽  
Fat Mass ◽  
Lean Mass ◽  
Gold Standard ◽  
Vertical Jump ◽  
Jump Height ◽  
Fat Percentage ◽  
Jump Performance ◽  
Total Body

Background of Study: Associations between measures of body composition and vertical jump height have previously been established using a range of instrumentation and prediction equations. Limited data has presented using gold standard measurements for both variables Objective: This investigation sought to examination the relationship between total body and lower extremity measures of body composition and vertical jump performance using gold standard measurements within an athletic population. Methods: Using a cross-sectional, correlational research design fourteen collegiate female volleyball athletes completed body composition, three countermovement jumps (CMJ) and three squat jumps (SJ) analysis using DXA and force platforms. Results: High to very high positive relationships were seen between total body lean (p < 0.001) and fat mass (p < 0.05), lower extremity lean and fat mass (p < 0.01), and CMJ force and power. High negative relationships were present between total body fat percentage(p < 0.05), total fat mass (p < 0.01) and CMJ jump height. Relationships between all body composition variables and SJ performance tended to be weaker, with the exception of total body lean mass (p < 0.05), lower extremity lean mass, and power output (p < 0.01). Conclusions: These findings support much of the previous literature in that increases of mass have subsequent increases in force and power production; however caution should be taken will increases in mass coming from fat or lean tissue.

A Comparative Analysis of Selected Ankle Orthoses during Functional Tasks

2001 ◽  
Vol 10 (3) ◽  
pp. 174-183 ◽  
Author(s):  
James A. Yaggie ◽  
Stephen J. Kinzey
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Vertical Jump ◽  
Plantar Flexion ◽  
Jump Height ◽  
Vertical Jump Height ◽  
Run Time ◽  
Joint Range ◽  
Shuttle Run ◽  
Ankle Bracing

Context:Ankle bracing has been used for many years in an attempt to prevent lateral ligamentous injuries of the ankle by restricting joint range of motion (ROM).Objective:To examine the influence of ankle bracing on ROM and sport-related performance.Design:Repeated measures.Setting:Biomechanics laboratory.Participants:30 volunteers. None reported ankle trauma within 2 years preceding the study or had other orthopedic conditions that would have affected physical performance.Intervention:Three brace conditions (McDavid A101™, Perform-8™ Lateral Stabilizer) were assessed during performance of the vertical jump and shuttle run.Main Outcome Measures:shuttle-run time, vertical jump height, inversion, and plantar flexion ROM.Results:Both braces restricted plantar flexion and inversion ROM and caused no change in shuttle-run time or vertical jump height.Conclusions:Our results indicate that bracing the ankle joint increases external lateral support to the joint without significantly restricting functional ability.

Ankle Bracing Decreases Vertical Jump Height and Alters Lower Extremity Kinematics

2016 ◽  
Vol 21 (2) ◽  
pp. 39-46 ◽  
Author(s):  
Bradley Smith ◽  
Tina Claiborne ◽  
Victor Liberi
Keyword(s):  
Lower Extremity ◽  
Vertical Jump ◽  
Plantar Flexion ◽  
Emg Activity ◽  
Jump Height ◽  
Jump Performance ◽  
Vertical Jump Height ◽  
Hip Flexion ◽  
Ankle Plantar Flexion ◽  
Ankle Bracing

The purpose of this study was to determine the effects of ankle bracing on vertical jump performance and lower extremity kinematics and electromyography (EMG) activity. Twenty healthy college athletes participated in two sessions, separated by a minimum of 24 hr. They performed five jumps with no brace on the first day, and five jumps with both ankles braced on the second day. An average of the three highest jumps each day was used for analysis. Braced vertical jump performance significantly decreased (p = .002) as compared with the unbraced condition. In addition, hip flexion (p = .043) and ankle plantar flexion (p = .001) angles were significantly smaller during the braced vertical jump. There was also a significant reduction in soleus muscle EMG (p = .002) during the braced condition.

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