jumping knee

INTRODUCTION: Return to Sport tests with functional hop tests are often used to decide when a person is ready to return to sport after an anterior cruciate ligament (ACL) injury. Poor movement quality, such as knee valgus, hip adduction and hip internal rotation is considered a risk factor for ACL injury. However, it is unclear whether existing tests adequately cover the aspect of movement quality. This study aims to investigate whether there is a relationship between the calculated limb symmetry index (LSI) of hop tests as an indication of performance and the total score of the "Quality First" assessment (movement quality)...

There is a paucity of literature analyzing the impact of fatigue from actual competitive soccer match-play on measures of neuromuscular function and muscle damage markers in youth players. Aims The main purpose was to analyze the acute pre- and post-competitive soccer match-play changes in measures of landing mechanics, stretch-shortening cycle capability, physical performance, muscle damage, and match intensity. A secondary purpose was to explore whether the players' maturity status and chronological age were associated with post-soccer match-play responses...

BACKGROUND: At the completion of formal rehabilitation after anterior cruciate ligament reconstruction, functional capacity is only restored in a small proportion of affected individuals. Therefore, the end of formal rehabilitation is not the end of functional rehabilitation. OBJECTIVE: To compare adherence to and effectiveness of a late-stage rehabilitation programme with usual care after anterior cruciate ligament (ACL) reconstruction. METHODS: This prospective, double-blind, multicentre, parallel group, randomised controlled trial, included people aged 18 to 35 years after formal rehabilitation completion (mean [SD] 241 [92] days post-reconstruction)...

Purpose: Maintaining physical fitness plays an important role in the management of people with cystic fibrosis (pwCF). Longitudinal data on the course of physical fitness and the potential impact of the introduction of highly effective CFTR modulator therapy with elexacaftor/tezacaftor/ivacaftor (ETI) in adult pwCF are scarce. Methods: Health-related and skill-related components of physical fitness were assessed using an incremental cycle test (Wpeak), plus forward bend (FB), prone bent knee hip extension (HE), plank leg raise (PLR), standing long jump (SLJ), and standing on one leg (OLS)...

Physical fitness plays a crucial role in determining human health and overall well-being. The objective of the study was to assess the changes in body structure and physical fitness among individuals examined in 2004 and 2022 (persons aged 32-34 and 50-52). The research material consists of data from the Krakow Continuous Study (KCS) of somatic development and physical fitness of people born in 1970 and 1972, conducted in Krakow in the years 1976-2022. In total, in 2004, 103 women and 122 men took part in the study, and in 2022-47 women and 67 men...

BACKGROUND: There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR). PURPOSE/HYPOTHESIS: This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population...

BACKGROUND: To date, no studies, to our knowledge, have compared the efficacy of autoregulated periodized and linear resistance exercises on anabolic myokines and muscular performance among recreationally active individuals. This study aimed to compare the effects of an 8-week autoregulated periodized resistance exercise (APRE) program with a linear resistance exercise (LRE) program on insulin-like growth factor-1 (IGF-1), follistatin (FST), myostatin (MST), body composition, muscular strength, and power in recreationally active males...

The purpose of this study was to calculate and compare (1) knee loads, (2) muscle-specific contributions to knee loads, and (3) effects of knee flexion angle on knee loads and muscle-specific load contributions during a forward jump-landing task in people with and without chronic ankle instability (CAI). Eight CAI patients and seven healthy controls performed a forward jump-landing task. We collected 3D kinematics, ground reaction force, and muscle activation and used musculoskeletal modeling. The results showed that only healthy controls exhibited an association between knee flexion angle and knee compressive impulse ( r  = 0...

PURPOSE: To investigate the landing strategies used after discontinuing and continuing the use of a functional knee brace (FKB) while performing a drop jump. METHODS: Following published methodology and power analysis, 23 uninjured male athletes, mean age of 19.4 ± 3.0 years, performed seven tests, during three test conditions (nonbraced, braced and removed brace or continued brace use), over 6 days of 12 testing sessions (S) for a total of 38...

The aim of the present study was to compare the differences in joint coordination patterns and variability in the lower extremity between the first and second landing phases of the drop jump. Eighteen resistance-trained men (age: 22.8 ± 1.8 years) performed drop jumps from a height of 0.40 m. An eight-camera motion capture system was utilized to record kinematic trajectories. Modified vector coding technique and circular statistics were used to determine the coordination pattern and variability of the following joint couples during the first and second landings: hip frontal-knee frontal (HfKf), hip sagittal-knee frontal (HsKf), hip sagittal-knee sagittal (HsKs), knee frontal-ankle frontal (KfAf), knee sagittal-ankle frontal (KsAf), and knee sagittal-ankle sagittal (KsAs)...

OBJECTIVES: To investigate the effect of combined balance and plyometric training (PT) on the agility and dynamic balance of adolescent taekwondo athletes. METHODS: Thirty female adolescent taekwondo players volunteered to participate and were randomly assigned to the combined balance training and PT (CT; n = 15) and PT (n = 15) groups. The CT group performed balance training combined with PT 3 times a week for 6 weeks (40 minutes of plyometrics and 20 minutes of balance training) while the PT group performed only PT for the same period (3 sets × 8-12 reps for each exercise)...

Torsional stiffness of athletic footwear plays a crucial role in preventing injury and improving sports performance. Yet, there is a lack of research focused on the biomechanical effect of torsional stiffness in badminton shoes. This study aimed to comprehensively investigate the influence of three different levels of torsional stiffness in badminton shoes on biomechanical characteristics, sports performance, and injury risk in badminton players. Fifteen male players, aged 22.8 ± 1.96 years, participated in the study, performing badminton-specific tasks, including forehand clear stroke [left foot (FCL) and right foot (FCR)], 45-degree sidestep cutting (45C), and consecutive vertical jumps (CVJ)...

PURPOSE: Resistance to fatigue is a key factor in injury prevention that needs to be considered in return-to-sport (RTS) scenarios, especially after severe knee ligament injuries. Fatigue should be induced under game-like conditions. The SpeedCourt (SC) is a movement platform for assessing multidirectional sprint performance, typical of game-sports, due to change-of-direction movements in response to a visual stimulus. Designing adequate fatigue protocols requires the suitable arrangement of several loading variables such as number of intervals, sprint distance or work/relief ratio (W:R)...

OBJECTIVES: Test batteries used to assess a patient's return-to-sports (RTS) following anterior cruciate ligament reconstruction (ACLR) are currently undergoing continual development, although no consensus exist on tests to be administered to athletes before allowing return to play. A simple standardized jump test battery was developed to objectively evaluate knee function following ACLR, thereby aiding in RTS decision-making. METHODS: Thirty-three patients who underwent ACLR were prospectively assessed pre-operatively, 6, and 12 months after surgery...

Force attenuation during landing requires coordinated motion of the ankle, knee, hip, and trunk, and strategies may differ between sexes. Sagittal plane coordination of the ankle/knee, knee/hip, and knee/trunk, and lower extremity and trunk kinematics and kinetics was compared throughout landing between 28 males and 28 females. Coordination was assessed with a modified vector coding technique and binning analysis. Total support moments (TSM), each joint's percent contribution, and timing of the TSM were compared...

Landing from a jump is a challenging task as the energy accumulated during the aerial phase of the jump must be fully dissipated by the lower limbs during landing; the higher the jump height, the greater the amount of energy to be dissipated. In the present study, we aim to understand (1) how the biomechanical behavior is tuned as a function of the mechanical demand, and (2) the relationship between the self-selected landing strategy and the behavior of the joints. Fourteen subjects were asked to drop off a box of 10 to 60 cm height and land on the ground...

INTRODUCTION: Tibial tubercle avulsion fractures are a rare lesion in adolescence that occurs during sports such as basketball, soccer, and volleyball. They result from a forceful extension of the knee against a fixed leg. CASE REPORT: Case 1: A 14-year-old adolescent who reportedly experienced severe knee pain when he jumped to head a ball during a soccer game. Case 2: A 17-year-old teenager who reportedly experienced severe knee pain on takeoff during a high jump event...

BACKGROUND: A limb symmetry index (LSI) of >90% for single-leg horizontal hop distance is recommended as a cutoff point for safe return to sports after anterior cruciate ligament reconstruction (ACLR). Despite achieving this threshold, abnormal lower limb biomechanics continue to persist in athletes after ACLR. Symmetry in single-leg vertical hop height appears to be more difficult to achieve and can be a better representation of knee function than single-leg horizontal hop distance...

BACKGROUND: Reactive decision-making during athletic movement has been demonstrated to evoke unfavorable biomechanics associated with anterior cruciate ligament (ACL) rupture. However, the current evidence is based on assessments of healthy individuals. We aimed to investigate unplanned jump landing kinetics and knee kinematics in ACL-reconstructed (ACLR) and non-injured athletes. METHODS: A total of 30 male professional soccer players (n = 15 ACLR after return to play, n = 15 matched controls) performed six drop landings onto a force plate...

The Squat Jump (SJ) test is widely recognized as a reliable test for assessing lower-limb explosive strength. However, uncertainty persists in the literature regarding the optimal starting positions for maximizing vertical jump performance. This uncertainty is exacerbated by a disproportionate focus on athletes in existing studies, with insufficient consideration being given to non-athletic women. To address this gap, this study investigated the influence of leg starting angle on explosive jump height in a homogeneous sample of non-athletic women...