342 Does hip strength predict dynamic valgus in female recreational runners?

Amateur runners usually run carrying implements in their hands (keys, a mobile phone, or a bottle of water). However, there is a lack of literature about the effects of different handloads on impact accelerations. Thus, this study aimed to analyse the effects of carrying different objects in the hand on impact accelerations during running. Nineteen male recreational runners (age 24.3 ± 6.8 years, training volume of 25 ± 7.38 km/week) performed twenty minutes of running on a treadmill at 2.78 m/s with four different conditions: no extra weight, with keys, with a mobile phone, and with a bottle of water. Impact acceleration and spatio-temporal parameters were analysed through a wireless triaxial accelerometry system composed of three accelerometers: two placed in each tibia and one placed on the forehead. A higher tibia acceleration rate in the dominant leg was observed when participants ran holding both a mobile phone (p = 0.027; ES = 0.359) and a bottle of water (p = 0.027; ES = 0.359), compared to no extra weight. No changes were observed in peak acceleration, acceleration magnitude, and shock attenuation in any other conditions. Likewise, neither stride frequency nor step length was modified. Our results suggest that recreational runners should not worry about carrying objects in their hands, like a mobile phone or a bottle of water, in short races because their effect seems minimal.

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Kinect Azure–Based Accurate Measurement of Dynamic Valgus Position of the Knee—A Corrigible Predisposing Factor of Osteoarthritis

Applied Sciences ◽

10.3390/app11125536 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5536

Author(s):

Ádám Uhlár ◽

Mira Ambrus ◽

Márton Kékesi ◽

Eszter Fodor ◽

László Grand ◽

...

Keyword(s):

Motion Capture ◽

Optical System ◽

Lower Limb ◽

Cruciate Ligament ◽

Movement Pattern ◽

Recognition Algorithm ◽

Predisposing Factor ◽

Lower Limb Injury ◽

Q Angle ◽

Dynamic Valgus

(1) Dynamic knee valgus is a predisposing factor for anterior cruciate ligament rupture and osteoarthritis. The single-leg squat (SLS) test is a widely used movement pattern test in clinical practice that helps to assess the risk of lower-limb injury. We aimed to quantify the SLS test using a marker-less optical system. (2) Kinect validity and accuracy during SLS were established by marker-based OptiTrack and MVN Xsens motion capture systems. Then, 22 individuals with moderate knee symptoms during sports activities (Tegner > 4, Lysholm > 60) performed SLS, and this was recorded and analyzed with a Kinect Azure camera and the Dynaknee software. (3) An optical sensor coupled to an artificial-intelligence-based joint recognition algorithm gave a comparable result to traditional marker-based motion capture devices. The dynamic valgus sign quantified by the Q-angle at the lowest point of the squat is highly dependent on squat depth, which severely limits its comparability among subjects. In contrast, the medio-lateral shift of the knee midpoint at a fixed squat depth, expressed in the percentage of lower limb length, is more suitable to quantify dynamic valgus and compare values among individual patients. (4) The current study identified a new and reliable way of evaluating dynamic valgus of the knee joint by measuring the medial shift of the knee-over-foot at a standardized squat depth. Using a marker-less optical system widens the possibilities of evaluating lower limb functional instabilities for medical professionals.

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Effects of caffeine ingestion on psychomotor state and oxidative stress markers after an 8-km run competition in sleep-deprived recreational runners

Biological Rhythm Research ◽

10.1080/09291016.2021.1925483 ◽

2021 ◽

pp. 1-13

Author(s):

Amir Khcharem ◽

Makram Souissi ◽

Rim Atheymen ◽

Wajdi Souissi ◽

Zouheir Sahnoun

Keyword(s):

Oxidative Stress ◽

Oxidative Stress Markers ◽

Caffeine Ingestion ◽

Stress Markers ◽

Recreational Runners ◽

And Oxidative Stress

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Persisting inter‐limb differences in patients following total hip arthroplasty four to five years after surgery? A preliminary cross‐sectional study

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04099-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Stefanie John ◽

David Weizel ◽

Anna S. Heumann ◽

Anja Fischer ◽

Katja Orlowski ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Center Of Pressure ◽

Operation Time ◽

Hip Strength ◽

Total Hip ◽

Control Subjects ◽

Post Surgery ◽

Flexion Extension ◽

Hip Flexion

Abstract Background Total hip arthroplasty (THA) is an effective procedure for patients with end-stage hip osteoarthritis. However, whether or not pre-operatively existing functional deficits are persisting several years post-surgery in the affected limb has not been thoroughly researched. Therefore, the primary aim of this preliminary study was to include patients four to five years after undergoing THA and to investigate potential differences between the operated and non-operated leg in hip strength, range of motion (ROM), balance, and gait. The secondary aim was to compare these values from the operated leg of the patients to those of the legs of healthy subjects. Methods Sixteen patients (age: 65.20 ± 5.32 years) following unilateral THA (post-operation time: 4.7 ± 0.7 years) and ten, healthy, age-matched control subjects (age: 60.85 ± 7.57 years) were examined for maximum isometric hip muscle strength, active ROM of the hip joint, balance and gait on both limbs. Paired t-tests were used to assess the inter-limb differences in the THA group. Analyses of covariance (ANCOVA) were performed to compare groups, using age as a covariate. Results The analysis of inter-limb differences in patients following THA revealed significant deficits on the operated side for hip abduction strength (p = 0.02), for hip flexion ROM (p < 0.01) and for balance in terms of the length of center of pressure (COP) (p = 0.04). Compared to values of the control subjects, the patients demonstrated significantly reduced hip strength in flexion, extension and abduction (p < 0.05) on the operated leg as well as reduced ROM measures in hip flexion, extension and abduction (p < 0.05). Conclusions The first results of this explorative study indicated that inter-limb differences as well as reduced hip strength and hip ROM compared with control subjects were still present four to five years after THA. These persisting asymmetries and deficits in patients following THA may be one explanation for the decrease in health-related quality of life (HRQoL) seen in patients over the years after surgery. Further studies are required to replicate these findings with a larger sample size. Trial registration DRKS, DRKS00016945. Registered 12 March 2019 – Retrospectively registered,

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Mechanics, energetics and implementation of grounded running technique: a narrative review

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2020-000963 ◽

2020 ◽

Vol 6 (1) ◽

pp. e000963

Author(s):

Sheeba Davis ◽

Aaron Fox ◽

Jason Bonacci ◽

Fiddy Davis

Keyword(s):

Postural Stability ◽

Injury Risk ◽

Metabolic Cost ◽

Duty Factor ◽

Vertical Oscillation ◽

Leg Stiffness ◽

Speed Range ◽

Impact Attenuation ◽

Acute Increase ◽

Recreational Runners

Grounded running predominantly differs from traditional aerial running by having alternating single and double stance with no flight phase. Approximately, 16% of runners in an open marathon and 33% of recreational runners in a 5 km running event adopted a grounded running technique. Grounded running typically occurs at a speed range of 2–3 m·s−1, is characterised by a larger duty factor, reduced vertical leg stiffness, lower vertical oscillation of the centre of mass (COM) and greater impact attenuation than aerial running. Grounded running typically induces an acute increase in metabolic cost, likely due to the larger duty factor. The increased duty factor may translate to a more stable locomotion. The reduced vertical oscillation of COM, attenuated impact shock, and potential for improved postural stability may make grounded running a preferred form of physical exercise in people new to running or with low loading capacities (eg, novice overweight/obese, elderly runners, rehabilitating athletes). Grounded running as a less impactful, but metabolically more challenging form, could benefit these runners to optimise their cardio-metabolic health, while at the same time minimise running-related injury risk. This review discusses the mechanical demands and energetics of grounded running along with recommendations and suggestions to implement this technique in practice.

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Validity of Recreational Marathon Runners’ Self-Reported Anthropometric Data

Perceptual and Motor Skills ◽

10.1177/0031512520930159 ◽

2020 ◽

Vol 127 (6) ◽

pp. 1068-1078

Author(s):

Pantelis T. Nikolaidis ◽

Beat Knechtle

Keyword(s):

Body Mass ◽

Assessment Method ◽

Fat Percentage ◽

Anthropometric Data ◽

Anthropometric Measures ◽

Marathon Runners ◽

Present Sample ◽

Large Samples ◽

Anthropometric Characteristics ◽

Recreational Runners

While studies on large samples of recreational runners have often relied on participants’ self-reported height and body mass, the validity of these data have not been investigated for this population. Hence, this study sought to examine the validity of self-reported anthropometric measures among recreational marathon runners. Female ( n = 32) and male ( n = 135) recreational marathon runners were requested to estimate their body mass and height (and we calculated their self-reported body mass index [BMI]), after which we took actual measures of their body mass and height and calculated their actual BMI. Participants’ self-reported values underestimated their actual body mass by 0.65 kg ( p < .001, η2 = 0.222) and their actual BMI by 0.35 kg ⋅ m−2 ( p < .001, η2 = 0.245). There was a significant Assessment Method × Sex Interaction for both body mass ( p = .019, η2 = 0.033) and BMI ( p = .017, η2 = 0.034), as women underestimated body mass values more than men. Participants overestimated their height by 0.44 cm ( p < .001, η2 = 0.075), but the interaction of sex and assessment method for height was not statistically significant. Underestimates of body mass correlated with marathon racing speed ( r = .24, p = .006) and body fat percentage ( r = −.29, p = .001) in men, but not in women ( p > .05). The disagreement between self-reported and measured anthropometric data in the present sample was lower than has been previously reported for the general population, suggesting that marathon runners may more accurately self-perceive and/or report their anthropometric characteristics. These findings are of practical value for health professionals and researchers (e.g., nutritionists and exercise physiologists) questionnaires to recreational marathon runners.

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