Extension Peak Torque Research Articles

No Differences Between Alter G-Trainer and Active and Passive Recovery Strategies on Isokinetic Strength, Systemic Oxidative Stress and Perceived Muscle Soreness After Exercise-Induced Muscle Damage.

Cooke, MB, Nix, C, Greenwood, L, and Greenwood, M. No Differences Between Alter G-Trainer and Active and Passive Recovery Strategies on Isokinetic Strength, Systemic Oxidative Stress and Perceived Muscle Soreness After Exercise-Induced Muscle Damage. J Strength Cond Res 32(3): 736-747, 2018-The incidence of muscle injuries is prevalent in elite sport athletes and weekend warriors and strategies that safely and effectively hasten recovery are highly desirable. The purpose of this study was to examine the differences between 3 recovery methods after eliciting muscle damage in recreationally active men relative to maximal isokinetic contractions, perceived muscle soreness, and psychological mood states. Twenty-five recreationally active men (22.15 ± 3.53 years, 75.75 ± 11.91 kg, 180.52 ± 7.3 cm) were randomly matched by V[Combining Dot Above]O2 peak (53.86 ± 6.65 ml·kg·min) and assigned to one of 3 recovery methods: anti-gravity treadmill (G-Trainer) (N = 8), conventional treadmill (N = 8) or static stretching (N = 9). Recovery methods were performed 30 minutes, 24, 48, and 72 hours after a 45-minute downhill run. Following eccentrically biased running, no significant differences were noted in isokinetic knee flexion and extension peak torque, systemic markers of muscle damage, oxidative stress and lipid peroxidation such as serum creatine kinase (CK), superoxide dismutase (SOD), and malondialdehyde (MDA), respectively, and subjective ratings of perceived muscle soreness between recovery methods. The G-Trainer group did however display a higher mood state as indicated by the Profile of Mood State global scores at 24 hours postexercise when compared to the conventional treadmill recovery group (p = 0.035). The improved mood state after the use of the anti-gravity treadmill may provide clinical relevance to other populations.

Anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone allograft: matched case control study

BackgroundQuadriceps tendon-patellar bone (QTPB) autograft is an excellent graft option with good clinical outcome. Use of QTPB autografts have increased because they minimize donor-site morbidity including anterior knee pain, while providing adequate mechanical strength. Although, there were many clinical results about allografts that used in anterior cruciate ligament (ACL) reconstruction, it have never been reported about the clinical outcome of ACL reconstruction with QTPB allograft.The purpose of this study is to evaluate the clinical outcome of ACL reconstruction with QTPB allograft and to compare with QTPB autograft. We hypothesized that ACL reconstruction with QTPB allograft had good functional outcomes and stability and no significant difference compared to the ACL reconstruction with QTPB autograft.MethodsFrom February 2009 to January 2014, 213 cases who received ACL reconstruction with QTPB grafts were included. Forty-five patients who received ACL reconstruction with QTPB allograft were individually matched in age, sex, direction of the injured knee and body mass index (BMI) to a control group of 45 patients who received QTPB autograft. Clinical results were evaluated using International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner scale, Knee injury and Osteoarthritis Outcome Score (KOOS) and ligament laxity. An average follow-up time was 31.2 months.ResultsThe functional scores and ligament laxity improved from initial to the last visit in those with ACL reconstruction with QTPB allograft (p < 0.05). No significant statistical difference was found in clinical outcomes and complications including re-rupture between the QTPB allograft and autograft groups (p > 0.05). Laxity using anterior drawer test, Lachman test and KT-2000 showed no significant difference. No significant difference was found between the two groups in quadriceps peak extension torque, except at 60° per second at 6 months.ConclusionQTPB allograft achieved good clinical outcome with no difference compared with QTPB autograft. QTPB allograft for ACL reconstruction is promising alternative to selected and compliant patients. Long-term follow-up needs to further evaluate the clinical outcomes and complications including re-rupture rate.

Relationship between sagittal spinal curves geometry and isokinetic trunk muscle strength in adults.

Sagittal spinal deviation has been reported to be a significant musculoskeletal problem affecting both genders and could develop at any age. Factors triggering this issue are still not well defined. The purpose of this study was to investigate the relationship between sagittal spine angles and isokinetic peak, average torque, and power of trunk muscles in asymptomatic adults. A convenient sample of 79 subjects with asymptomatic spine participated in this study. Thoracic and lumbar curves angles were measured using the Formetric 4D device. Thoracolumbar (T/L) ratio was calculated as an indicator of spine balance. Isokinetic peak and average torque and average power for trunk flexors and extensors were measured at 60°/s in seated and semi-standing test positions. Lumbar curve angle was moderately inversely correlated (p<0.001) with peak extension torque (ρ=-0.532 and -0.495 in seated and semi-standing positions, respectively) and peak flexion torque (ρ=-0.604 and -0.542 in seated and semi-standing positions, respectively). The T/L ratio was found to be significantly associated (p<0.001) with trunk extension torque (ρ=0.422 and 0.378 in seated and semi-standing positions, respectively) and trunk flexion torque (ρ=0.396 and 0.321 in seated and semi-standing positions, respectively). Similarly, average torque and power measurements were significantly correlated with lumbar curve angle and T/L ratio. Sagittal spine balance is associated with trunk muscles strength in adults, particularly, the lumbar spine muscles. Therefore, assessment of sagittal spinal balance and trunk muscles strength should be taken into consideration when designing rehabilitation programs for correction of sagittal spine curvature.

Muscle strength is impaired in men but not in women living with HIV taking antiretroviral therapy.

There is evidence that HIV antiretroviral therapy adverse effects may be sex-dependent, but data examining these sex differences in muscle strength is scarce. Our aim was to compare dynamic and isokinetic parameters of muscle strength between HIV-infected men and women to HIV-uninfected subjects. In this cross-sectional study, muscle strength was evaluated in 44 HIV-infected (20 men, 24 women) and 25 age-, race- and body mass index-matched HIV-uninfected subjects (11 men, 14 women). We assessed knee flexion and extension efforts in isokinetic dynamometer at angular velocities of 60° and 180°/s, and 1 repetition maximum test (1RM) for bench press, leg press and arm curl exercises, respectively. Lean body mass (LBM) was measured using bioelectrical impedance. HIV-infected men had significantly less dynamic muscle strength for 1RM total (262.5 versus 357.2 kg), bench press (48.6 versus 60.3 kg), leg press (182.7 versus 261 kg) and arm curl (31.2 versus 36.5 kg) compared to HIV-uninfected men (P≤0.05); no differences were found among women. Men had lower values for peak torque in extension and flexion movements at 60°/s and 180°/s, while HIV-infected women presented higher peak torque in extension movement at 60°/s compared to controls. No differences were found in LBM. Moreover, isokinetic evaluation demonstrated that HIV-infected subjects showed greater acceleration and deceleration time in some variables, compared to controls, related to difficulty in activating motor units. HIV infection is associated with impaired dynamic and isokinetic strength in men compared to HIV-uninfected controls, but not in women.

Whole-body Vibration Training as a Supportive Therapy During Allogeneic Haematopoietic Stem Cell Transplantation – A Randomised Controlled Trial

Effects of whole-body vibration (WBV) training in patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) remain unknown. We examined whether additional WBV training during hospitalisation may stabilise the physical capacity of patients undergoing allogeneic HSCT, improve health-related quality of life (HRQOL) and fatigue status of these patients. In this randomised controlled trial, 26 subjects were randomly allocated 1:1 in an intervention group (INT; n=13) or a control group (CON; n=13). Patients in the CON received conventional physical therapy and patients in the INT completed further WBV training every other day. Isokinetic measurement of the muscular capacity of the lower extremities, functional endurance capacity and HRQOL were evaluated before and after the intervention period. No unwanted side effects were observed. We found a significant positive effect of the intervention on the maximum relative peak torque in extension in the INT compared to the CON (p=0.019) and patients in the INT experienced less pain (p=0.05). WBV training can be successfully implemented as a supportive therapy for patients undergoing allogeneic HSCT. Furthermore, WBV training represents a safe and effective option in the maintenance of muscular capacity of the musculature of the lower extremities and may contribute to pain release.

Effectiveness of a low-fat yoghurt supplemented with rooster comb extract on muscle strength in adults with mild knee pain and mechanisms of action on muscle regeneration.

To determine the effects of the intake of low-fat yoghurt supplemented with rooster comb extract (RCE) on muscle strength. 148 subjects, with mild knee pain, participated in a randomized, placebo-controlled, double-blind, and parallel study. Muscle strength, knee effusion, and pain perception were measured. C2C12 myoblasts were used to elucidate the mechanisms of action involved. RCE improved total work and mean power in men, and also peak torque in extension by 10%. RCE reduced synovial effusion by 11.8% and pain perception by 24.6%. Both RCE and HA increased myoblast proliferation by 29%, while RCE reduced myoblast differentiation by 36.2%, suggesting a beneficial role of RCE in muscle regeneration. Low-fat yoghurt supplemented with RCE improved muscle strength. This effect is partially explained by muscle regeneration enhancement, reduced synovial effusion, and reduced pain perception, which could exert a beneficial clinical impact on men affected by mild knee pain.

The relationship between isokinetic strength and functional performance tests in patients with knee osteoarthritis.

[Purpose] The main purpose of the study was to examine the relationship of a battery of frequently used functional assessment tests with quadriceps and hamstrings isokinetic strength in Knee-osteoarthritis (OA) patients. Secondarily, the predictability of isokinetic strength on these performance variables was also assessed. [Subjects and Methods] Seventeen males and 23 females with Knee-OA, were assessed via a) the common functional tests: 6-minute walk test, Timed up-and-go test, 30-second chair test and 12-stair test and b) isokinetic concentric extension-flexion at 120°/s and 180°/s. [Results] Both Knee Extension and Flexion Peak Torque per Body weight showed moderate to strong, statistically significant correlation, with all 4-functional performance tests, for both velocities. Both 12-stair test and 30-second chair test were significant predictors in all analyses, while the 6-minute walk test was an additional significant predictor of the 120°/s knee flexion. [Conclusion] Thigh muscle strength in both tested velocities proved to be significantly correlated with functional performance. The 12-stair test and 30-second chair test results were significant predictors for isokinetic extension and flexion in both velocities. It appears that those two tests challenge the knee and the surrounding musculature in a manner that reflects muscle strength.

Effectiveness of air pulsed cryotherapy on delayed onset muscle soreness of elbow flexors following eccentric exercise

Cryotherapy is widely used in sports to facilitate recovery from exercise-induced muscle damage that often results from strenuous training and/or competition. However, a paucity of evidence exists on the therapeutic values of repeated air pulsed cryotherapy (CRYO) application to suggest its usefulness to clinicians, coaches, sports scientists and athletes in the field of sports and rehabilitation. Aim: This study investigates the effectiveness of CRYO on the recovery from delayed onset of muscle soreness (DOMS) induced by eccentric exercise. Materials and methods: Thirty-two participants (21.31±1.03 years; height 1.72±0.05 m; BMI 22.15±1.69 kg.cm-2) were equally randomized into CRYO group and control group (CONT). DOMS was induced by eccentric contractions of elbow flexors. Visual analogue scale score (VAS), mid arm circumference (MAC), pressure pain threshold (PPT), range of motion of active elbow flexion (ROM-AF), passive elbow flexion (ROM-PF), active elbow extension (ROM-AE), passive elbow extension (ROM-PE) and isometric peak torque of elbow flexors (IPT) were measured at pre-exercise (PRE), immediately, 1, 2, 3, 4, and 7 days post exercise. Results and discussion: There were significant interactions effect (group X time) with (P<0.05) for VAS, MAC, PPT, ROM-PF, ROM-AE, and ROMPE. Additionally, all outcome measures (except for ROM-AF and IPT) demonstrated a significant improvement (P<0.05) in DOMS recovery in the CRYO group compared to CONT group. Conclusion: A 20 minutes (4 session X5 minutes) session for 5 consecutive days of repeated air pulsed cryotherapy has beneficial effects on the recovery of DOMS on elbow flexors from eccentric exercise.

Sports Physical Therapy Section Poster Presentations (Abstracts SPO1-SPO166).

These abstracts are presented here as prepared by the authors. The accuracy and content of each abstract remain the responsibility of the authors. In the identification number above each abstract, SPO designates a Sports Physical Therapy Section poster presentation. J Orthop Sports Phys Ther 2018;48(1):A203-A276. doi:10.2519/jospt.2018.48.1.A203.

Early-Onset Physical Frailty in Adults With Diabesity and Peripheral Neuropathy.

Diabesity (obesity and diabetes mellitus) has been identified as a potential contributor to early-onset frailty. Impairments contributing to early onset of physical frailty in this population are not well understood, and there is little evidence of the impact of peripheral neuropathy on frailty. The purpose of this study was to determine impairments that contribute to early-onset physical frailty in individuals with diabesity and peripheral neuropathy. We studied 105 participants, 82 with diabesity and peripheral neuropathy (57 years of age, body mass index [BMI] 31 kg/m2); 13 with diabesity only (53 years of age, BMI 34 kg/m2) and 10 obese controls (67 years of age, BMI 32 kg/m2). Peripheral neuropathy was determined using Semmes Weinstein monofilaments; physical frailty was classified using the 9-item, modified Physical Performance Test; and knee extension and ankle plantarflexion peak torques were measured using isokinetic dynamometry. Participants with diabesity and peripheral neuropathy were 7.4 times more likely to be classified as physically frail. Impairments in lower-extremity function were associated with classification of frailty. Individuals with diabesity and peripheral neuropathy are particularly likely to be classified as frail. Earlier identification and interventions aimed at improving lower-extremity function may be important to mitigate the early-onset functional decline.

Muscle Strength, But Not Muscle Oxidative Capacity, Varies Between the Morning and the Afternoon in Patients with Multiple Sclerosis: A Pilot Study.

Despite frequent muscle strength or muscle oxidative capacity (based on exercise-onset oxygen uptake [VO2] kinetics) assessments in patients with multiple sclerosis, the impact of time of day on these parameters is often not taken into account. Based on observations in healthy subjects, it remains to be studied whether muscle strength, and/or exercise-onset VO2 kinetics, varies between the morning and the afternoon in patients with multiple sclerosis. In this prospective observational pilot study, walking capacity, exercise-onset VO2 kinetics, isometric knee extension/flexion strength (dynamometry), and self-reported fatigue were measured in 11 patients with multiple sclerosis (age, 51.8 ± 9.3 yrs; body mass index, 24.7 ± 5.1 kg/m; Expanded Disability Status Scale, 3.5 ± 1.4; 3 men) in the morning and 5 hrs later (afternoon). In the afternoon, self-reported fatigue (1.9 ± 0.9 cm) and muscle strength (knee extension peak torque at 45 degrees, 84 ± 26 Nm) were significantly different (P < 0.05), than in the morning (self-reported fatigue, 1.2 ± 0.9 cm; knee extension peak torque at 45 degrees, 93 ± 32 Nm), but walking capacity and exercise-onset VO2 kinetics were similar at these two time points (P > 0.05). Consistent with observations in healthy subjects, muscle strength varies between the morning and the afternoon in patients with multiple sclerosis, under the conditions of the present study. These findings suggest that muscle strength assessments should be conducted at similar or nearly similar times of the day to minimize diurnal variation in these measures and hence insure correct interpretation.

Kinetic mechanism of electroacupuncture for stair climbing in knee osteoarthritis patients

To observe the kinetic change that reflects joint loading in different planes during stair climbing in knee osteoarthritis (KOA) after electroacupuncture (EA) by three-dimensional motion analysis, so as to provide reference for its biomechanical mechanism treated with acupuncture. Forty KOA patients, in accordance with the random number table, were assigned into an observation group and a control group, 20 cases in each one and finally 18 cases completed. Acupoints in the observation group were Neixiyan (EX-LE 4), Dubi (ST 35), Yanglingquan (GB 34), Yinlingquan (SP 9), Xuehai (SP 10), Liangqiu (ST 34) and Zusanli (ST 36); points in the control groups were located about 2 cm next to the above acupoints with shallow acupuncture. EA was connected at Neixiyan (EX-LE 4) and Yinlingquan (SP 9), Liangqiu (ST 34) and Yanglingquan (GB 34). The frequency was 2 Hz with continuous wave in the observation group and there was no current in the control group for the corresponding points. All the treatment was given for 3 weeks, totally 11 times. Climbing stairs gait was measured before and after treatment. Velocities and kinetic parameters during ascending and descending stairs were analyzed, including flexion and extension peak torques of hip, knee, ankle on the vertical plane, external knee adduction moment on the coronal plane. After treatment in the observation group, velocities during ascending and descending stairs significantly increased (P<0.05, P<0.01); maximal ankle plantar flexor moments during ascending and descending stairs and the second peak external knee adduction moment (PEKAM2) during ascending stairs significantly increased (P<0.05, P<0.01). After treatment in the control group, the first peak external knee adduction moment (PEKAM1) and PEKAM2 during descending stairs were less than those before treatment (P<0.05, P<0.01). In the observation group, the difference value (DV) of velocity before and after treatment was positively correlated to DV in the torque of ankle plantar flexors during ascending stairs in the observation group (r=0.598，P<0.01). Excluding the impact of velocity, the DV of the maximal torque of ankle plantar flexors during ascending stairs didn't show difference in the observation group (P>0.05). EA can increase the velocities of ascending and descending stairs of KOA patients. It improves the loading capacity of knee joint on both sagittal and coronary planes. But its effect during ascending may be correlated with the increase of velocity. The mechanism of different effects between EA and minimal acupuncture on joint moments is still unclear and warrants further study.

The effect of magnesium supplementation on muscle fitness: a meta-analysis and systematic review.

Increasing evidence supports a role of magnesium (Mg) in skeletal muscle function. However, no systematic review or meta-analysis has summarized data on Mg supplementation in relation to muscle fitness in humans. Thus, this study aimed to quantitatively assess the effect of Mg supplementation on muscle fitness. A meta-analysis and systematic review. Medline database and other sources were searched for randomized clinical trials through July 2017. Studies that reported results regarding at least one of the following outcomes: leg strength, knee extension strength, peak torque, muscle power, muscle work, jump, handgrip, bench press weights, resistant exercise, lean mass, muscle mass, muscle strength, walking speed, Repeated Chair Stands, and TGUG were included. Measurements of the association were pooled using a fixed-effects model and expressed as weighted mean differences (WMDs) with 95% confidence intervals (95% CIs). Fourteen randomized clinical trials targeting 3 different populations were identified: athletes or physically active individuals (215 participants; mean age: 24.9 years), untrained healthy individuals (95 participants; mean age: 40.2 years), and elderly or alcoholics (232 participants; mean age: 62.7 years). The beneficial effects of Mg supplementation appeared to be more pronounced in the elderly and alcoholics, but were not apparent in athletes and physically active individuals. The results of the meta-analysis suggested that no significant improvements in the supplementation group were observed regarding isokinetic peak torque extension [WMD=0.87; 95% CI=(-1.43, 3.18)], muscle strength [WMD=0.87; 95% CI=(-0.12, 1.86)] or muscle power [WMD=3.28; 95% CI=(-14.94, 21.50)]. Evidence does not support a beneficial effect of Mg supplementation on muscle fitness in most athletes and physically active individuals who have a relatively high Mg status. But Mg supplementation may benefit individuals with Mg deficiency, such as the elderly and alcoholics.

Design of virtual reality training program for prevention of falling in the elderly: A pilot study on complex versus balance exercises

IntroductionVirtual reality (VR) exercises have been investigated as a rehabilitation paradigm to reduce the risk of falling in the elderly. This study aimed to compare a VR program consisted of complex exercises and that of balance exercises. MethodsThe study was a single-blind, randomized, comparative trial conducted over 5 weeks. Twenty subjects over 65 years of age were divided into a complex exercise with virtual reality (CEVR) group and a balance exercise with virtual reality (BEVR) group. CEVR consisted of strengthening, flexibility, endurance, and balance exercises, while BEVR focused on balance exercises only. Before and after 10 times of 1h training sessions, we measured isokinetic peak torque and total work of knee muscles using a dynamometer. The Timed Up & Go (TUG) test was also conducted to evaluate dynamic balance. ResultsKnee extension peak torque was significantly enhanced only in the CEVR group (p<0.05), but there was no difference between groups. Both groups showed significant improvement of dynamic balance measured by TUG after training sessions, but the CEVR group exhibited greater improvement than the BEVR group (p<0.05). ConclusionsOur findings demonstrate the superiority of the virtual reality training with a complex exercise program to improve balance and muscle strength in the elderly when compared to the BEVR. As a training for prevention of falling in the elderly, we recommend a virtual reality program including various exercises for strength, endurance, balance, and flexibility.

Effect of 12-month resistance and endurance training on quality, quantity, and function of skeletal muscle in older adults requiring long-term care

Older adults requiring long-term care will experience age-associated deterioration of the quality and quantity of skeletal muscle if no interventions are performed. Long-term training is considered a typical intervention method and is effective for improvement of both muscle quantity and physical function. However, how such training affects muscle quality [i.e., fat-to-muscle ratio as determined by echo intensity (EI)] in older adults requiring long-term care remains unclear. The purpose of this study was to investigate the effects of a 12-month physical training intervention on the quality and quantity of skeletal muscle, physical function, and blood chemistry in older adults requiring long-term care. Seventeen older adults requiring long-term care (Tr-group) and 15 healthy older adults (Cont-group) participated in this study. Patients in the Tr-group performed exercises consisting of resistance and endurance training once or twice a week for 12months. The EI and muscle thickness of the thigh were calculated from the rectus femoris and biceps femoris using B-mode transverse ultrasound images. Physical functions (isometric knee extension peak torque, sit-to-stand test, 5-m normal/maximal speed walking, handgrip strength, and timed up and go test) and blood lipid components including adipocytokines were measured at three points, i.e. baseline and 6 and 12months after. The thigh EI was significantly lower after 6months of training than baseline, and it returned to the initial level after 12months of training (baseline, 70.2±8.3a.u.; 6months, 64.1±11.2a.u.; 12months, 72.3±7.2a.u.). The thigh muscle thickness, 5-m maximal speed walking, and knee extension torque were significantly improved after 12months of training (P<0.05). The blood chemistry parameters did not significantly change. These results demonstrate that a 12-month training intervention contributes to improvement of muscle quantity and function with tentative changes in muscle quality but has no effect on blood chemistry in older adults requiring long-term care. We conclude that this type of training has the potential to restore the muscle functional abilities of older adults requiring long-term care.

Mechanomyography and Torque during FES-Evoked Muscle Contractions to Fatigue in Individuals with Spinal Cord Injury.

A mechanomyography muscle contraction (MC) sensor, affixed to the skin surface, was used to quantify muscle tension during repetitive functional electrical stimulation (FES)-evoked isometric rectus femoris contractions to fatigue in individuals with spinal cord injury (SCI). Nine persons with motor complete SCI were seated on a commercial muscle dynamometer that quantified peak torque and average torque outputs, while measurements from the MC sensor were simultaneously recorded. MC-sensor-predicted measures of dynamometer torques, including the signal peak (SP) and signal average (SA), were highly associated with isometric knee extension peak torque (SP: r = 0.91, p < 0.0001), and average torque (SA: r = 0.89, p < 0.0001), respectively. Bland-Altman (BA) analyses with Lin’s concordance (ρC) revealed good association between MC-sensor-predicted peak muscle torques (SP; ρC = 0.91) and average muscle torques (SA; ρC = 0.89) with the equivalent dynamometer measures, over a range of FES current amplitudes. The relationship of dynamometer torques and predicted MC torques during repetitive FES-evoked muscle contraction to fatigue were moderately associated (SP: r = 0.80, p < 0.0001; SA: r = 0.77; p < 0.0001), with BA associations between the two devices fair-moderate (SP; ρC = 0.70: SA; ρC = 0.30). These findings demonstrated that a skin-surface muscle mechanomyography sensor was an accurate proxy for electrically-evoked muscle contraction torques when directly measured during isometric dynamometry in individuals with SCI. The novel application of the MC sensor during FES-evoked muscle contractions suggested its possible application for real-world tasks (e.g., prolonged sit-to-stand, stepping,) where muscle forces during fatiguing activities cannot be directly measured.

Design of a lightweight, tethered, torque-controlled knee exoskeleton.

Lower-limb exoskeletons show promise for improving gait rehabilitation for those with chronic gait abnormalities due to injury, stroke or other illness. We designed and built a tethered knee exoskeleton with a strong lightweight frame and comfortable, four-point contact with the leg. The device is structurally compliant in select directions, instrumented to measure joint angle and applied torque, and is lightweight (0.76 kg). The exoskeleton is actuated by two off-board motors. Closed loop torque control is achieved using classical proportional feedback control with damping injection in conjunction with iterative learning. We tested torque measurement accuracy and found root mean squared (RMS) error of 0.8 Nm with a max load of 62.2 Nm. Bandwidth was measured to be phase limited at 45 Hz when tested on a rigid test stand and 23 Hz when tested on a person's leg. During bandwidth tests peak extension torques were measured up to 50 Nm. Torque tracking was tested during walking on a treadmill at 1.25 m/s with peak flexion torques of 30 Nm. RMS torque tracking error averaged over a hundred steps was 0.91 Nm. We intend to use this knee exoskeleton to investigate robotic assistance strategies to improve gait rehabilitation and enhance human athletic ability.

Low-load high-velocity resistance exercises improve strength and functional capacity in diabetic patients

This study investigated the effects of low-load high-velocity resistance exercises on neuromuscular and functional outcomes in patients with Type 2 diabetes (T2D) during the early-phase of resistance training. Thirty participants with T2D performed 18 training sessions (6 weeks – 3x week) in one of two groups: low-load high-velocity exercises (LLHV, n=15, 62.1±10.5 years) or recreational activities (RA, n=15 56.7 ± 19.4 years). LLHV performed resistance exercises with 3x 8reps as fast as possible with 50-60% 1RM. RA performed light activities. Strength, power, and functional tests were assessed. There was significant increasing in the knee extension peak-torque at 60°/s (7.6%) and 180°/s (12.2%), rate of force development in the LLHV group (P<0.05), whereas there were no changes in the RA group. Significant increases in functional test were observed in the LLHV group (P<0.01) with no changes in the RA group. In conclusion, the LLHV induced marked improvements in neuromuscular parameters, as well as in the functional capacity of participants with T2D.

Trunk Strength Characteristics of Elite Alpine Skiers - a Comparison with Physically Active Controls.

Core muscle imbalances and weak trunk strength are relevant for injury prevention and performance. Information regarding core strength requirements and ideal flexion/extension ratios in alpine skiing is limited. We aimed to compare trunk strength capacities in elite alpine skiers with those of a matched control group. The concentric maximal trunk flexion and extension of 109 elite skiers and 47 active controls were measured at 150°/s in a ballistic mode using the CON-TREX® TP 1000 test system. The relative flexion peak torque was higher in male ski racers (p = 0.003; 2.44 ± 0.30 Nm/kg) than in the controls (2.32 ± 0.42 Nm/kg). The relative peak torque for extension was 4.53 ± 0.65 Nm/kg in ski racers and 4.11 ± 0.52 Nm/kg in the controls (p = 0.001). Female athletes were significantly stronger in both, relative flexion force (p = 0.006; skiers 2.05 ± 0.22 Nm/kg; controls 1.74 ± 0.28 Nm/kg) and relative extension force (p = 0.001; skiers 3.55 ± 0.53 Nm/kg; controls 3.14 ± 0.48 Nm/kg). No significant differences were found in the ratios of flexion to extension forces in females and males. Ski racers are engaged in extensive strength training for both leg and trunk muscles, which explains the higher peak values. Both groups indicated a low ratio from 0.54-0.59, which represents high trunk extensor muscles strength relative to flexor muscles.

Aging effect on the instrumented Timed-Up-and-Go test variables in nursing home women aged 80\u201393\xa0years

Although the total “Timed-Up-and Go” test (TUG) performance time can characterize an age-related decline of general mobility, this result alone doesn’t give any detailed information about the test subtasks. The primary objective of the study was to identify in nursing home women a variable extracted from instrumented TUG (iTUG) that is the best predictor of age. The secondary objective was to assess whether this variable is associated with the results of the isometric knee extension peak torque (IKEPT); lower limb strength measured by the 30-s chair stand test (30sCST), and walking capacity measured by the 6-min walk test (6MWT). Twenty-six women (mean ± SD: age—85.8 ± 3.6 years; body weight—59.4 ± 12.3 kg; body height—151.0 ± 7.3 cm; BMI—26.0 ± 4.9 kg/m2) performed iTUG (while wearing a body-fixed inertial sensor) and functional tests. Total iTUG performance time significantly correlated with age (r = 0.484; p < 0.05), 30sCST (r = −0.593; p < 0.01), and 6MWT (r = −0.747; p < 0.001) but not with absolute nor relative IKEPT (p > 0.05). Additionally, the subjects’ age correlated with 30sCST (r = −0.422; p < 0.05), 6MWT (r = −0.482; p < 0.05), IKEPT (r = −0.392; p < 0.05) and IKEPT/FFM (r = −0.407; p < 0.05). Five out of 16 analyzed iTUG variables were significantly related to age, and multiple regression analysis showed the best correlation with the sit-to-stand vertical acceleration range (STSVAR) (r2 = 0.430; SEE = 3.041; β = −0.544 ± 0.245; B = −1.204 ± 0.543; p < 0.05). Moreover, STSVAR was significantly associated with %Fat (r = 0.415; p < 0.05), 30sCST (r = 0.519; p < 0.01), 6MWT (r = 0.585; p < 0.01) but not with absolute nor relative IKEPT (p > 0.05). The obtained results suggest that in the oldest old group of nursing home women an age-related decline in TUG performance is mainly associated with a reduction of “explosive” strength of lower limb muscles.