Flexor Peak Torque Research Articles

Exploring associations between neuromuscular performance, hypermobility, and children’s motor competence

ObjectivesTo evaluate if neuromuscular performance and hypermobility are factors associated with children’s motor competence. DesignCross-sectional observation study. MethodsData was collected on 60 children aged 6–12 years; motor competence was determined using the Movement Assessment Battery for Children-2 test, with children classified into 3 groups (Typically Developing n=30; ‘At Risk’ of low motor competence (LMC) n=9; LMC n=21). Neuromuscular performance was determined utilising the Resistance Training Skills Battery for Children (RTSBc), 5-repetition maximum (5RM) leg press and Biodex dynamometry to assess isometric and isokinetic peak torque of the knee flexors and extensors. Hypermobility was measured using the Beighton and Lower Limb Assessment Score. ResultsBetween-groups MANCOVA revealed typically developing children scored significantly higher on the RTSBc than those ‘at risk’ of LMC (p=0.021) and those in the LMC group (p<0.001). 5RM scores also differed between groups, with typically developing children achieving significantly higher scores than the LMC group. No differences were found between groups for isometric or isokinetic measures of strength. Sequential regression analysis revealed neuromuscular performance variables explained 44.7% of the variance in motor competence, with RTSBc (p<0.001) and 5RM (p=0.019) emerging as positive significant predictors. Hypermobility failed to explain significant variance in motor competence beyond that explained by neuromuscular performance. ConclusionsNeuromuscular performance of children varies according to levels of motor competence, with those with LMC performing poorly on tasks requiring multi-joint movement. Furthermore, neuromuscular performance predicted almost half the variance observed in motor competence and highlights a novel intervention strategy.

No Significant Differences in Muscle Growth and Strength Development When Consuming Soy and Whey Protein Supplements Matched for Leucine Following a 12 Week Resistance Training Program in Men and Women: A Randomized Trial.

There are conflicting reports regarding the efficacy of plant versus animal-derived protein to support muscle and strength development with resistance training. The purpose of this study was to determine whether soy and whey protein supplements matched for leucine would comparably support strength increases and muscle growth following 12 weeks of resistance training. Sixty-one untrained young men (n = 19) and women (n = 42) (18–35 year) enrolled in this study, and 48 completed the trial (17 men, 31 women). All participants engaged in supervised resistance training 3×/week and consumed 19 grams of whey protein isolate or 26 grams of soy protein isolate, both containing 2 g (grams) of leucine. Multi-level modeling indicated that total body mass (0.68 kg; 95% CI: 0.08, 1.29 kg; p < 0.001), lean body mass (1.54 kg; 95% CI: 0.94, 2.15 kg; p < 0.001), and peak torque of leg extensors (40.27 Nm; 95% CI: 28.98, 51.57 Nm, p < 0.001) and flexors (20.44 Nm; 95% CI: 12.10, 28.79 Nm; p < 0.001) increased in both groups. Vastus lateralis muscle thickness tended to increase, but this did not reach statistical significance (0.12 cm; 95% CI: −0.01, 0.26 cm; p = 0.08). No differences between groups were observed (p > 0.05). These data indicate that increases in lean mass and strength in untrained participants are comparable when strength training and supplementing with soy or whey matched for leucine.

Association between Lysholm score and muscular torque deficit after anterior cruciate ligament reconstruction.

The asymmetry of muscular strength after anterior cruciate ligament reconstruction (ACLR) is associated with increase in the development of new lesions. This asymmetry is precisely assessed by isokinetic dynamometry which is a high-cost technique, limited to major centers and hospitals. Thus, the aim of this study was to test the accuracy of one of the most frequently used functional questionnaires, the Lysholm score, to diagnose the knee torque deficit. In total, 115 patients were evaluated after ACLR. Knee symptoms were evaluated using the Lysholm questionnaire and knee extensor and flexor peak torque during maximal isokinetic concentric contractions at 60° s-1 (5 repetitions) and 180° s-1 (15 repetitions). Patients with <20% peak torque deficit were considered symmetric (normal). An increase in the Lysholm score was associated with a deficit reduction in the peak torque of knee extensors at 60° s-1 (r = -0.294) and 180° s-1 (r = -0.297) (p < 0.05 for both). Cutoff Lysholm scores of >90 points for 60° s-1 allowed the correct diagnosis of symmetry in 71% and of >89 points for 180º·s-1 allowed the correct diagnosis of symmetry in 73%, for knee extensors. Patients with a Lysholm score of >89 points presented an isokinetic deficit 36% lower than patients with a Lysholm score of ≤89 points (p < 0.05). A Lysholm score of >89 points has predictive value for deficits in the peak torque of knee extension (<20%). However, replacement of the isokinetic evaluation by this instrument must be performed with caution because of its accuracy.

Effect of Aging on Trunk Muscle Function and Its Influence on Falls Among Older Adults.

The objective was to determine whether trunk muscle function is influenced by the aging process and to identify if the trunk can be an important factor in older people's falls over a period of 1 year. The peak torque, rate of torque development, and torque steadiness of the trunk extensors and flexors were compared between a young group, older group (older adults with no episodes of falls), and older faller group (older adults who had suffered at least one fall episode over a period of 1 year) by one-way analysis of variance, followed by the post hoc Tukey test. The adjusted multivariate linear regression was applied to verify the association between the number of falls and the trunk parameters in older adults. The young group showed higher extensors and flexors peak torque and rate of torque development, and lower extensor torque steadiness at 10% when compared with older groups. Only trunk flexor peak torque showed a negative association with the number of future falls (p = .042), but there was no difference in trunk muscle function between the older group and the older faller group.

The Effects of Tourniquet Application in Total Knee Arthroplasty on the Recovery of Thigh Muscle Strength and Clinical Outcomes.

The present randomized controlled study aims to evaluate whether tourniquet application during total knee arthroplasty (TKA) has an effect on (1) thigh muscle strength (quadriceps and hamstring muscle strength) and (2) clinical outcomes (postoperative knee range of motion [ROM], postoperative pain level, and Knee Society Score [KSS]). The effects of tourniquet application during TKA were investigated in 65 patients randomly allocated to one of two groups: TKA with a tourniquet and TKA without a tourniquet. Patients in both groups were comparable in terms of the demographic and clinical data (p > 0.05 for age, number of patients, sex, radiographic gonarthrosis grade, American Society of Anesthesiologists [ASA] classification, and body mass index [BMI]). All patients in both groups were operated by the same surgeon using one type of prosthesis. Isokinetic muscle strength (peak torque and total work) of knee extensors (quadriceps) and flexors (hamstrings) was measured in Newton meters (Nm) using a CYBEX 350 isokinetic dynamometer (HUMAC/CYBEX 2009, Stoughton, MA). The combined KSS (knee score + function score), visual analog scale (VAS), and knee ROM were measured preoperatively and at 1 and 3 months postoperatively to evaluate clinical outcomes. There were no significant differences between the two groups in preoperative and postoperative values of isokinetic muscle strength (peak torque and total work) and aforementioned clinical outcomes (p < 0.05). The present study has shown that quadriceps strength and clinical outcomes were not improved in the early postoperative period (3 months) when a tourniquet was not used during TKA.

Relationships between Body Build and Knee Joint Flexor and Extensor Torque of Polish First-Division Soccer Players

The aim of the study is to identify the relationships between anthropometric variables and knee joint extensor peak torque, knee joint flexor peak torque, and conventional hamstring-to-quadriceps ratio in Polish first-division soccer players. The study examined 37 soccer players aged 19 to 30 years (body mass: 76.8 ± 7.2 kg, body height 1.82 ± 0.06 m). Muscle torques of the knee joint were measured under isometric conditions using a Biodex 4 Pro dynamometer. The anthropometric variables such as body part lengths, breadths, and girths and skinfold thickness were measured. The strongest relationships of knee joint extensors were observed with body mass and variables describing skeleton size and lower-limb muscles. Regarding knee flexor torque, a significant relationship was found only with body mass. However, no significant relationships were observed between the conventional hamstring-to-quadriceps ratio and the anthropometric variables studied. The regression analysis results identified body height, body mass, and thigh and calf girth as the features most associated with knee joint torque. However, anthropometric measurements do not provide full information about the torque proportions of antagonist muscle groups, which is very important for injury prevention. Therefore, measurements using special biomechanical equipment are also necessary for the comprehensive analyses and control of the effects of sports training.

Effect of 4-week cyclic stretching program on muscle properties and physical performance in healthy adult men.

The short-term effect of cyclic stretching (CS) has been found to decrease muscle hardness and improve physical performance. However, the long-term effect of CS program was unclear. This study investigated the long-term effect of CS program on muscle properties and physical performance. Eighteen healthy men participated in this study. The participants were assigned randomly to either the CS or control group (9 participants in each group) to conduct 2 min CS of the plantar flexor muscles 5 times a week for 4 weeks. Before and after intervention, the gastrocnemius medialis muscle hardness, muscle-tendon joint (MTJ) angle, and MTJ displacement (ΔMTJ) were measured as indices of muscle properties. In addition, the maximum range of motion of ankle dorsiflexion (ROM max), normalized maximum peak torque of plantar flexor (NPT), vertical jump height, and dynamic postural stability, dynamic postural stability index (DPSI) were measured as indices of physical performance. The CS program was found to significantly decrease muscle hardness and increase vertical jump height and ROM max, but not to change the MTJ angle, ΔMTJ, NPT, and DPSI. The results of our study suggested that long-term CS program was effective in decreasing muscle hardness and increasing vertical jump height.

Effect of aging on the association between ankle muscle strength and the control of bipedal stance.

Previous studies reported a significant association between postural control and lower-limb strength of several muscle groups, however, they were focused especially on knee muscles and ankle plantar and dorsal flexors. The aim of the present study is to examine the correlation between the muscle strength of ankle invertors, evertors, plantar flexors, and dorsal flexors and the control of bipedal stance in young and older adults. Thirty one young (aged 22.8 ± 2.6 years) and thirty one older adults (aged 70.5 ± 7.2 years) voluntarily participated in this study. Ankle muscle strength was evaluated by an isokinetic dynamometer. Normalized peak torque and work were averaged for four repetitions and for both lower limbs. The control of bipedal stance was evaluated by the sample entropy derived from an accelerometer placed on the lumbar spine while the subject stood on a foam pad with eyes open. Results showed significant age-related differences in ankle muscle strength and sample entropy in medial-lateral direction. More interestingly, the correlation between ankle muscle strength and the sample entropy was significantly different between young and older adults. Indeed, no significant correlation was observed in the younger adults. Conversely, in the older adults, the work of the ankle evertors positively correlated with sample entropy in the medial-lateral direction during bipedal stance (r = 0.36), whereas the peak torque and work of the dorsal flexors were significantly correlated with sample entropy in the anterior-posterior direction during bipedal stance (r = 0.44 for both variables). In the young adults, results suggest that, standing on foam with eyes open is a relatively easy postural task that does not require the full ankle muscle strength capacity. Taken together, the present findings suggest that older adults have a different association between ankle muscle strength and the sample entropy during bipedal stance.

A Three-Dimensional Musculoskeletal Model of the Western Lowland Gorilla Foot: Examining Muscle Torques and Function

Due to difficulty of obtaining accurate quantitative data on foot muscles, relatively little has been done to study foot muscle function in non-human apes. Gorilla feet are known to be similar in bony proportions and mechanics to those of humans, hence are key to understanding human foot evolution and its ecological context. We present the first 3D musculoskeletal computer model of a western lowland gorilla foot, giving muscle torques about the tarsometatarsal, metatarsophalangeal and interphalangeal joints of digits 2–5. Peak flexor torque around the fifth metatarsophalangeal joint occurs at a highly flexed position, suggesting an ability to maintain flexed postures around lateral metatarsophalangeal joints, useful for grasping vertical supports. For distal interphalangeal joints, flexor torques peaked the more medial the digit at relatively flexed postures. We report, for the first time, interossei acting upon proximal and distal interphalangeal joints. All these facilitate maintenance of flexed positions around distal interphalangeal joints, likely used for grasping of small supports/objects. Humans lack these features, suggesting that semi-arboreal early hominins made less use of the peripheral canopy than gorillines. Information here could be used in gorilla enclosure design to encourage wild-type locomotor repertoires in captivity.

Short-term resistance training with instability reduces impairment in V wave and H reflex in individuals with Parkinson's disease.

This study had two objectives: 1) to compare the effects of 3 wk of resistance training (RT) and resistance training with instability (RTI) on evoked reflex responses at rest and during maximal voluntary isometric contraction (MVIC) of individuals with Parkinson's disease (PD) and 2) to determine the effectiveness of RT and RTI in moving values of evoked reflex responses of individuals with PD toward values of age-matched healthy control subjects (HCs) (z-score analysis). Ten individuals in the RT group and 10 in the RTI group performed resistance exercises twice a week for 3 wk, but only the RTI group included unstable devices. The HC group (n = 10) were assessed at pretest only. Evoked reflex responses at rest (H reflex and M wave) and during MVIC [supramaximal M-wave amplitude (Msup) and supramaximal V-wave amplitude (Vsup)] of the plantar flexors were assessed before and after the experimental protocol. From pretraining to posttraining, only RTI increased ratio of maximal H-reflex amplitude to maximal M-wave amplitude at rest (Hmax/Mmax), Msup, Vsup/Msup, and peak torque of the plantar flexors (P < 0.05). At posttraining, RTI was more effective than RT in increasing resting Hmax and Vsup and in moving these values to those observed in HCs (P < 0.05). We conclude that short-term RTI is more effective than short-term RT in modulating H-reflex excitability and in increasing efferent neural drive, approaching average values of HCs. Thus short-term RTI may cause positive changes at the spinal and supraspinal levels in individuals with PD. NEW & NOTEWORTHY Maximal H-reflex amplitude (Hmax) at rest and efferent neural drive [i.e., supramaximal V-wave amplitude (Vsup)] to skeletal muscles during maximal contraction are impaired in individuals with Parkinson's disease. Short-term resistance training with instability was more effective than short-term resistance training alone in increasing Hmax and Vsup of individuals with Parkinson's disease, reaching the average values of healthy control subjects.

Cardiorespiratory fitness and muscular strength of deaf futsal players.

The present study compared the cardiopulmonary exercise capacity and peak torque of the knee extensor and flexor muscles in team players associated with the Gaucho Deaf Futsal Federation players to those of their hearing peers. In this cross-sectional study, 16 male athletes, eight futsal players with hearing impairment (deaf group, DG; 22.6±7.7 years), and eight futsal players with normal hearing (control group, CG; 22.5±2.9 years) underwent a cardiopulmonary test on a treadmill and isokinetic dynamometry at 60°/sec. All athletes were subjected to a cardiopulmonary test on a treadmill and isokinetic dynamometry at 60°/sec. The main results showed a reduction in the cardiorespiratory fitness of deaf athletes when compared to the control group maximal oxygen consumption (VO2max) (40.3±9.8 mL/kg/min vs. 50.7±4.7 mL/kg/min, P= 0.01), oxygen pulse (15.3±4.8 mL/bpm vs. 20.7±2.6 mL/bpm, P=0.01) and ventilation (70.1±22 L/min vs. 96.2±15 L/min, P=0.01), respectively. The relative torque peak of the dominant knee flexors was significantly lower in the deaf group when compared to the control (1.5±0.2 N.m/kg vs. 1.9±0.2 N.m/kg, P=0.004), respectively. There was a significant correlation between VO2max and peak torque of the dominant knee flexors (rs=0.83, P<0.001) and extensors (rs=0.65, P=0.006). When compared to players with normal hearing, deaf players showed lower cardiorespiratory fitness and decreased knee flexor strength. The performance of the thigh muscles was associated with aerobic capacity.

Velocity-specific knee strength between professional and under-17 female volleyball players.

BackgroundMany studies have investigated isokinetic performance in volleyball players but not through surface maps.ObjectivesThe goals of this study were to assess velocity-specific isokinetic knee extensor–flexor muscle strength and to compare the isokinetic knee extensor–flexor muscles between professional (PRO) and under-17 (U17) female volleyball players.MethodThis cross-sectional laboratory study was developed with two groups: PRO (n = 12), medianage = 21.3 years, and U17 (n = 9), medianage = 15 years. Peak torque, total work, mean power, angle of peak torque, hamstring–quadriceps torque ratio (H–Q ratio) and torque–angle–velocity surface maps were analysed from knee extension–flexion at 60, 120 and 300 degrees per second (°/s).ResultsSignificant differences were identified for extensor peak torque between PRO x = 202.3 Newton metre (N·m) (standard deviation [SD] = 24.4) and U17 x = 141.6 N·m (30.1) at 60 °/s (p < 0.001; d = 2.21) as well as flexor peak torque (PRO x = 75.7 N·m [10.3] and U17 x = 57.7 N·m [11.4]) at 120 °/s (p < 0.001; d = 1.65) for the dominant limb. There were also significant group differences for total work and mean power at all velocities for extension and flexion. Surface maps demonstrated higher torque at lower speeds for both groups with smaller torque changes across velocities for flexion.ConclusionDifferent groups of female volleyball players showed contrasting concentric knee muscle strength across isokinetic velocities.Clinical implicationsThese results demonstrate the importance of specific strength training for different age groups, even within the same sport, and provide insight into muscle strength.

Effect of Resistance Training on Muscular Function and Functional Mobility in Adults with Cerebral Palsy

Cerebral Palsy (CP) is a non-progressive neurological disorder due to damage in the brain leading to musculoskeletal dysfunction and immobility. Physical deconditioning of individuals with CP appears to accelerate muscle atrophy and osteoporosis; thus, adults with CP are more prone to fall and fracture. The lower state of balance and functional mobility is also related to the higher risk of fall in the general public, and resistance training is known to improve overall muscular strength and functional mobility. However, equivocal results were reported whether resistance training has a positive effect on muscular function and balance in CP population. PURPOSE: To determine the influence of resistance training to muscular strength and balance in adults with CP who already developed muscle atrophy and osteoporosis. METHODS: Twenty adults with and without CP were recruited. Seven CP participants completed post-exercise experiments after performing resistance training twice a week for three months. Muscular strength (torque, work, and power) at 90, 150, and 210 0/sec were assessed in the leg using the Humac Norm Isokinetic Dynamometer. Functional mobility was assessed from the Berg Balance Test, and limits of stability test using the Biodex balance system. RESULTS: CP group had significantly lower knee extensor peak torque (e.g., 11.8±2.3 CP vs. 68±12.5 control, ft-lbs, P<0.05), and lower knee flexor peak torque (e.g., 6.3±1.6 CP vs. 43.8±7.9 control, ft-lbs, P<0.05) compared to control. After 3 months of training, CP group did not show statistical differences in muscular strength [e.g., extensor peak torque (27.5±17.0 pre vs. 31.5±24.2 post, ft-lbs, P>0.05), and flexor peak torque (9.3±5.6 pre, vs. 15.0±10.9 post, ft-lbs, P>0.05], or balance [e.g. overall score (25.2±16.1 pre vs. 24.3±11.4 post p>0.05) on limit of stability test, total score (18.0±19.5 pre vs. 24.4±21.6 p>0.05) on Berg Balance test. However, individuals who improved peak torque in knee flexors and extensors also improved postural stability via the Berg balance test. CONCLUSIONS: These preliminary findings suggest that muscular strength influences functional mobility in adults with CP only after exercise training.

Hamstring rate of torque development is more affected than maximal voluntary contraction after a professional soccer match

Match-induced fatigue of knee muscle strength and agonist-antagonist strength-ratios may affect both performance and risk of injury in soccer players. Once explosive tasks are imperative in soccer as well as hamstring strain injuries occur during high-velocity moments, rapid force capacity of this muscle group is especially important. This study evaluated the effect of match-induced fatigue on knee muscle strength and strength-ratio parameters after a single professional soccer match. Male professional soccer players (n = 16; 24.2 ± 3.9 years) were tested before and after a soccer match (56.2 ± 22.6 min of playing) for knee flexors (hamstring) and extensors (quadriceps) isometric peak torque (MVC) and rate of torque development (RTD) – as well as the hamstring-to-quadriceps ratio (H:Q) – at 30° of knee flexion. Knee injuries often occur at this joint angle, which is common in sprinting, pivoting, sidecutting, and jumping. Match-induced fatigue caused a left shift in the knee extensors torque-time curve with no significant change in both early (i.e. 0–50 ms) and late (i.e. 0–200 ms) RTD, and a right shift in the knee flexors torque-time curve with a decrease in early RTD (∼16%, p = .029) and late RTD (∼11%, p = .011). Knee extensors and knee flexors peak torque remained unchanged (p > .05). Early RTD H:Q decreased by∼24% (p = .027), while late RTD H:Q and MVC H:Q remained unchanged (p > .05). In conclusion, match-induced fatigue impaired the ability to rapidly produce force at an angle where injuries are most susceptible to occur. Important information is missed if only the traditional H:Q is considered.

MON-205 Is Muscle Mechanical Function Altered In Polycystic Ovary Syndrome?

Context: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of women of reproductive age, characterized by androgen excess, ovulatory dysfunction and polycystic ovaries (PCOM). Limited and conflicting data are available regarding musculoskeletal system and muscle strength in PCOS. Objective: The aim of the current study was to assess muscle mechanical function in PCOS and its relation with hormonal and metabolic features of the syndrome. Design: The study included 44 women with PCOS, all having clinical or biochemical hyperandrogenism, chronic oligo-anovulation and PCOM (2003 Rotterdam criteria – phenotype A), and 32 age- and BMI-matched healthy women. Anthropometric, hormonal and biochemical measurements were performed in all participants. Muscle mechanical function including lower limb explosive strength and average power was measured by using isokinetic dynamometry, a valid and reliable instrument for measuring muscle strength. Results: The mean age and BMI of the women with PCOS and healthy controls were 21.8+3.2 versus 22.8+3 years and 26.1+5.4 versus 25.5+5.7 kg/m2 respectively (p=NS for both). PCOS patients had higher modified Ferriman-Gallwey (mFG) scores and higher levels of bioavailable testosterone (bT) than controls (p<0.05 for both), whereas fasting glucose and fasting insulin levels were similar between the groups. Isokinetic measurement of quadriceps and hamstring strength were performed by Biodex 3 dynamometer at an angular velocity of 60°/s. The peak muscle force output during the assessment was defined as the peak torque (PTQ) and was reported as body weight-normalized (Nm/kg) PTQ. Average power (AvP) was determined by the time-averaged integrated area under the curve at 60°/s angular velocity. The normalized values of knee extensor and flexor PTQ at 60°/s were similar between patients and controls whereas these values were higher in normal weight individuals compared to overweight-obese individuals (p<0.05 for both). The AvP at 60°/s with extension and flexion was significantly higher in PCOS group (50.3+21.2 vs 42.1+11.6 and 35.3+27 vs 22.2+11.1 respectively, p <0.05 for both). These measurements were correlated with bT (r=0.29, p=0.012, r=0.36, p=0.001 respectively). Conclusion: Muscle mechanical function is altered in PCOS. Women with PCOS have increased average lower limb power that is associated with hyperandrogenism.

Physical Response to a Simulated Period of Soccer-Specific Fixture Congestion.

Page, RM, Marrin, K, Brogden, CM, and Greig, M. Physical response to a simulated period of soccer-specific fixture congestion. J Strength Cond Res 33(4): 1075-1085, 2019-The aim of this study was to assess the physiological, perceptual, and mechanical measures associated with the completion of a simulated period of short-term soccer-specific fixture congestion. Ten male semiprofessional soccer players completed 3 trials of a treadmill-based match simulation, with 48 hours interspersing each trial. A repeated measures general linear model identified significantly (p = 0.02) lower knee flexor peak torque (PT) recorded at 300°·s in the second (141.27 ± 28.51 N·m) and third trials (139.12 ± 26.23 N·m) when compared with the first trial (154.17 ± 35.25 N·m). Similarly, muscle soreness (MS) and PT data recorded at 60°·s were significantly (p ≤ 0.05) different in the third trial (MS = 42 ± 25 a.u; PT60 = 131.10 ± 35.38 N·m) when compared with the first trial (MS = 29 ± 29 a.u; PT60 = 145.61 ± 42.86 N·m). Significant (p = 0.003) differences were also observed for mean electromyography (EMGmean) of bicep femoris between the third trial (T0-15 = 126.36 ± 15.57 μV; T75-90 = 52.18 ± 17.19 μV) and corresponding time points in the first trial (T0-15 = 98.20 ± 23.49 μV; T75-90 = 99.97 ± 39.81 μV). Cumulative increases in perceived exertion, heart rate, oxygen consumption, blood lactate concentrations, EMGmean, and PlayerLoad (PL) were recorded across each trial. Muscle soreness and PT were also significantly different after trial. There were, however, no significant main effects or interactions for the salivary immunoglobulin A and the medial-lateral PL metrics. These data suggest a biomechanical and muscular emphasis with residual fatigue, with implications for injury risk and the development of recovery strategies.

Profiling the Isokinetic Muscle Strength of Athletes Involved in Sports Characterized by Constantly Varied Functional Movements Performed at High Intensity: A Cross‐Sectional Study

Constantly varied functional movements performed at high intensity (FMHI) is a type of strength and general conditioning program that has gained widespread popularity in recent years. The very intense exercises performed with lower and upper limbs may create muscular asymmetry or imbalance between agonist and antagonist muscles, and therefore the characterization of isokinetic muscle strength, side-to-side difference, and balance ratios for lower and upper limbs may contribute to a better understanding of the modality characteristics. To evaluate the knee and shoulder strength of FMHI athletes of both sexes. Cross-sectional study. Exercise physiology laboratory. Sixty FMHI athletes (30 M/30 W) with more than 2 years' experience. Athletes performed isokinetic tests in both lower and upper limbs: concentrically at 60°/s and 240°/s and eccentrically at 240°/s. Isokinetic peak torque of knee flexor and extensor and shoulder internal and external rotator muscles. Conventional and functional strength balance ratios and side-to-side strength difference. Concentric peak torque values relative to total body mass for shoulder and knee joints were higher in men than women on both sides. Eccentric peak torque values for knee flexor-dominant and extensor-nondominant limbs showed no difference between the sexes. The knee conventional strength balance ratio for dominant and nondominant sides in women (51.5% ± 7.0% and 51.0% ± 7.1%, respectively) and for dominant and nondominant sides in men (54.4% ± 15.2% and 51.5% ± 9.9%, respectively) were no different between the sexes or limbs. The shoulder conventional strength balance ratio was higher in women (78.1 ± 13.2%) than in men (67.6% ± 10.9%) on the nondominant side. Knee and shoulder functional strength balance ratios in nondominant limbs were higher for women than men. Both sexes presented no side-to-side difference for knee joints or muscles, or for shoulder IR muscles, but ER was stronger in dominant limbs. These data from highly trained FMHI athletes can be compared to that of other athletes to help determine individual weaknesses, strengths, and imbalances, and may be useful for designing training programs. III.

Superior knee flexor strength at 2years with all-inside short-graft anterior cruciate ligament reconstruction vs a conventional hamstring technique.

To compare the "all-inside technique" for anterior cruciate ligament (ACL) reconstruction using a short, quadrupled semitendinosus tendon (ST4) autograft and suspensory cortical fixation on both the femoral and tibial side vs the "conventional technique" using a semitendinosus/gracilis (ST/G) autograft fixed with a suspensory device on the femoral side and with an interference screw on the tibial side, in terms of clinical and functional outcomes. A total of 90 patients were enrolled, randomised into two groups, and prospectively followed. Group A comprised 45 patients treated with the all-inside technique and Group B included 45 patients treated with the conventional ACL technique (55 males, 35 females; mean age 28.7 ± 11.3years). Patients completed the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Score (KOOS), and the Knee Society Score (KSS) preoperatively and at 2years postoperatively. Anterior tibial translation measurement (KT-1000 arthrometer) and isokinetic testing of the operative vs non-operative limb were also conducted and the limb symmetry index (LSI) was determined. At 24 months, the Lysholm, IKDC, KOOS, and KSS scores between the two groups were similar (n.s.). Anterior tibial translation between the operative and non-operative knee was also similar among the two groups (n.s.). Patients of Group A had significantly higher mean LSIs in terms of flexor peak torque (1.0 ± 0.1 vs 0.9 ± 0.1; p < 0.001), time-to-peak (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) and total work (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) at 180°/s, and significantly better mean LSI for isometric flexor/extensor ratio at 90° (1.1 ± 0.3 vs 0.8 ± 0.2; p < 0.001). The all-inside ACL reconstruction with an ST4 autograft and cortical button fixation on both ends is a viable alternative to the conventional technique. It affords preservation of knee flexor strength, which is of advantage, especially when treating athletes with ACL injury. I.

Strength, Jump Heights and Physical Characteristics of Young Male Basketball Players by Their Positions

The aim of the study is to compare isokinetic leg strengths and jump performances of basketball players playing at different positions. A total of 34 basketball players (guards (n=13), forwards (n=13) and centers (n=7)) from 17 teams of Turkish Basketball Development League participated in the study. The isokinetic strength tests were performed for the dominant limb at two different angular speeds (60°s-1 and 180°s-1) and the extensor and flexor peak torques (EPT and FPT) were recorded. The strengths produced according to weight were taken as relative EPT and FPT. Jump tests were performed in three categories: free jump, 120° squat jump and active jump. Multivariate variance analysis (ANOVA) was used to compare players' scores in strength and jump tests by their positions. In the comparison of the positions, the guards were shorter and slimmer than the forwards and centers (p &lt;0.05), and they were found to have less BMI values than the centers. The absolute strength values obtained with knee extension peak torques for both angular velocities were higher in the centers than the guards (p &lt;0.05). There was no statistically significant difference in the relative strength values. Moreover, no statistically significant difference was found between the groups for other parameters and all jump parameters (p&gt; 0.05). Consequently, it can be stated that there are physical differences among high-level young basketball players by their positions and absolute quadriceps strengths of the centers may be higher than of the guards.

Peak torque angle of anterior cruciate ligament-reconstructed knee flexor muscles in patients with semitendinosus and gracilis autograft is shifted towards extension regardless of the postoperative duration of supervised physiotherapy.

BackgroundThe observational cohort study investigated whether the flexor muscles peak torque (PT) angle shifting towards extension observed in the involved knee in patients after anterior cruciate ligament reconstruction (ACLR) using semitendinosus and gracilis tendon (STGR) autograft is associated with the postoperative physiotherapy supervision duration.MethodsFrom 230 ACL-reconstructed males, we identified patients after ACLR utilizing STGR autograft and divided them into those who completed supervised physiotherapy <6 months (Group I; n = 77) and those who completed supervised physiotherapy ≥6 months (Group II; n = 66). The mean follow-up time was 6.84 ± 1.47 months. The ACL-reconstructed patients were compared to 98 controls (Group III). Bilateral knee flexor muscle PT measurements were performed. The relative PT at 180°/s (RPT), PT angle at 180°/s, and range of motion at 180°/s were analysed. The RPT limb symmetry index (LSI) was calculated. Tests for dependent samples, one-way analysis of variance, post hoc test, and linear Pearson’s correlation coefficient (r) calculations were performed.ResultsThe shift towards extension was noted when comparing the ACL-reconstructed limb to the uninvolved limb (Group I, p ≤ 0.001; Group II, p ≤ 0.001) and to Group III (p ≤ 0.001), but it was not correlated with physiotherapy supervision duration (r = -0.037, p = 0.662). In ACL-reconstructed patients, there was a moderate association of supervision duration and knee flexor LSI (r = 0.587, p < 0.001).ConclusionsThe ACL-reconstructed knee flexors PT angle shift towards extension was observed regardless of the duration of postoperative physiotherapy supervision. However, the analysis revealed that the duration of supervised physiotherapy positively influenced the RPT and LSI in patients after the ACLR.