scholarly journals Changes in Lower Extremity Biomechanics Due to a Short-Term Fatigue Protocol

2013 ◽  
Vol 48 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Nelson Cortes ◽  
Eric Greska ◽  
Roger Kollock ◽  
Jatin Ambegaonkar ◽  
James A. Onate

Context: Noncontact anterior cruciate ligament injury has been reported to occur during the later stages of a game when fatigue is most likely present. Few researchers have focused on progressive changes in lower extremity biomechanics that occur throughout fatiguing. Objective: To evaluate the effects of a sequential fatigue protocol on lower extremity biomechanics during a sidestep-cutting task (SS). Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: Eighteen uninjured female collegiate soccer players (age = 19.2 ± 0.9 years, height = 1.66 ± 0.5 m, mass = 61.6 ± 5.1 kg) volunteered. Intervention(s): The independent variable was fatigue level, with 3 levels (prefatigue, 50% fatigue, and 100% fatigue). Using 3-dimensional motion capture, we assessed lower extremity biomechanics during the SS. Participants alternated between a fatigue protocol that solicited different muscle groups and mimicked actual sport situations and unanticipated SS trials. The process was repeated until fatigue was attained. Main Outcome Measure(s): Dependent variables were hip- and knee-flexion and abduction angles and internal moments measured at initial contact and peak stance and defined as measures obtained between 0% and 50% of stance phase. Results: Knee-flexion angle decreased from prefatigue (−17° ± 5°) to 50% fatigue (−16° ± 6°) and to 100% fatigue (−14° ± 4°) (F2,34 = 5.112, P = .004). Knee flexion at peak stance increased from prefatigue (−52.9° ± 5.6°) to 50% fatigue (−56.1° ± 7.2°) but decreased from 50% to 100% fatigue (−50.5° ± 7.1°) (F2,34 = 8.282, P = 001). Knee-adduction moment at peak stance increased from prefatigue (0.49 ± 0.23 Nm/kgm) to 50% fatigue (0.55 ± 0.25 Nm/kgm) but decreased from 50% to 100% fatigue (0.37 ± 0.24) (F2,34 = 3.755, P = 03). Hip-flexion angle increased from prefatigue (45.4° ± 10.9°) to 50% fatigue (46.2° ± 11.2°) but decreased from 50% to 100% fatigue (40.9° ± 11.3°) (F2,34 = 6.542, P = .004). Hip flexion at peak stance increased from prefatigue (49.8° ± 9.9°) to 50% fatigue (52.9° ± 12.1°) but decreased from 50% to 100% fatigue (46.3° ± 12.9°) (F2,34 = 8.639, P = 001). Hip-abduction angle at initial contact decreased from prefatigue (−13.8° ± 6.6°) to 50% fatigue (−9.1° ± 6.5°) and to 100% fatigue (−7.8° ± 6.5°) (F2,34 = 11.228, P < .001). Hip-adduction moment decreased from prefatigue (0.14 ± 0.13 Nm/kgm) to 50% fatigue (0.08 ± 0.13 Nm/kgm) and to 100% fatigue (0.06 ± 0.05 Nm/kg) (F2,34 = 5.767, P = .007). Conclusions: The detrimental effects of fatigue on sagittal and frontal mechanics of the hip and knee were visible at 50% of the participants' maximal fatigue and became more marked at 100% fatigue. Anterior cruciate ligament injury-prevention programs should emphasize feedback on proper mechanics throughout an entire practice and not only at the beginning of practice.

2018 ◽  
Vol 34 (4) ◽  
pp. 327-335 ◽  
Author(s):  
Bradley S. Beardt ◽  
Myranda R. McCollum ◽  
Taylour J. Hinshaw ◽  
Jacob S. Layer ◽  
Margaret A. Wilson ◽  
...  

Previous studies utilizing jump-landing biomechanics to predict anterior cruciate ligament injuries have shown inconsistent findings. The purpose of this study was to quantify the differences and correlations in jump-landing kinematics between a drop-jump, a controlled volleyball-takeoff, and a simulated-game volleyball-takeoff. Seventeen female volleyball players performed these 3 tasks on a volleyball court, while 3-dimensional kinematic data were collected by 3 calibrated camcorders. Participants demonstrated significantly increased jump height, shorter stance time, increased time differences in initial contact between 2 feet, increased knee and hip flexion at initial contact and decreased peak knee and hip flexion for both left and right legs, and decreased knee–ankle distance ratio at the lowest height of midhip for the 2 volleyball-takeoffs compared with the drop-jump (P < .05, Cohen’s dz ≥ 0.8). Significant correlations were observed for all variables between the 2 volleyball-takeoffs (P < .05, ρ ≥ .6) but were not observed for most variables between the drop-jump and 2 volleyball-takeoffs. Controlled drop-jump kinematics may not represent jump-landing kinematics exhibited during volleyball competition. Jump-landing mechanics during sports-specific tasks may better represent those exhibited during sports competition and their associated risk of anterior cruciate ligament injury compared with the drop-jump.


2020 ◽  
Vol 11 (1) ◽  
pp. 130
Author(s):  
Datao Xu ◽  
Xinyan Jiang ◽  
Xuanzhen Cen ◽  
Julien S. Baker ◽  
Yaodong Gu

Volleyball players often land on a single leg following a spike shot due to a shift in the center of gravity and loss of balance. Landing on a single leg following a spike may increase the probability of non-contact anterior cruciate ligament (ACL) injuries. The purpose of this study was to compare and analyze the kinematics and kinetics differences during the landing phase of volleyball players using a single leg (SL) and double-leg landing (DL) following a spike shot. The data for vertical ground reaction forces (VGRF) and sagittal plane were collected. SPM analysis revealed that SL depicted a smaller knee flexion angle (about 13.8°) and hip flexion angle (about 10.8°) during the whole landing phase, a greater knee and hip power during the 16.83–20.45% (p = 0.006) and 13.01–16.26% (p = 0.008) landing phase, a greater ankle plantarflexion angle and moment during the 0–41.07% (p < 0.001) and 2.76–79.45% (p < 0.001) landing phase, a greater VGRF during the 5.87–8.25% (p = 0.029), 19.75–24.14% (p = 0.003) landing phase when compared to DL. Most of these differences fall within the time range of ACL injury (30–50 milliseconds after landing). To reduce non-contact ACL injuries, a landing strategy of consciously increasing the hip and knee flexion, and plantarflexion of the ankle should be considered by volleyball players.


Neurology ◽  
2021 ◽  
Vol 98 (1 Supplement 1) ◽  
pp. S21.2-S22
Author(s):  
Ryan Moran

ObjectiveTo examine the relationship between the m-CTSIB and Landing Error Scoring System in a sample of collegiate female athletes.BackgroundRecent literature has linked concussion and neuromuscular deficits in the lower extremity after injury. Neuromuscular control is frequently assessed using balance measures for concussion, but also dynamically to identify anterior cruciate ligament injury (ACL) risk via jump-landing movement screening.Design/MethodsThirty-nine healthy, collegiate female soccer (n = 22) and volleyball (n = 17) athletes completed the modified-Clinical Test of Sensory Interaction of Balance (m-CTSIB) and the Landing Error Scoring System (LESS). Measures consisted of total m-CTSIB sway index scores on individual conditions (firm surface eyes open [condition 1] and eyes closed [2], foam surface eyes open [3] and eyes closed [4]), m-CTSIB overall score, and total LESS errors. LESS scores were also categorized into a low (0–4 errors) and high (5 + errors) risk to determine if athletes with worse neuromuscular control on the LESS has worse balance on the m-CTSIB. A Spearman's rank-order correlation was conducted to determine the strength of the relationship between LESS and m-CTSIB performance. A series of Mann-Whitney U test were performed to determine differences between low and high LESS performance on m-CTSIB performance.ResultsThere was a weak, negative correlation between LESS and m-CTSIB performance (rs(37) = −0.153, p = 0.35). Further, there were no differences between the low and high risk LESS groups on sway index scores on conditions 1 (U = 158.5, p = 0.39), 2 (U = 156.0, p = 0.36), 3 (U = 165.5, p = 0.51), or 4 (U = 128.5, p = 0.08), as well as overall m-CTSIB scores (U = 150.5, p = 0.28).ConclusionsThere appears to be a lack of relationship between the LESS and m-CTSIB tests, revealing the independence of static and dynamic lower extremity neuromuscular function. Athletes who may be more at risk for ACL injury due to abnormal jump-landing biomechanics, do not differ from low-risk athletes on baseline balance assessment.


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