Journal of Functional Morphology and Kinesiology

14 pages, 686 KB

Open AccessArticle

Associations Between Isokinetic Knee Strength at Different Angular Velocities and Explosive Jump Performance in Young Female Athletes: A Pilot Study

by Daniela Falat Leütterová and Jaroslav Sučka

J. Funct. Morphol. Kinesiol. 2026, 11(2), 237; https://doi.org/10.3390/jfmk11020237 (registering DOI) - 13 Jun 2026

Abstract

Background: Isokinetic strength of the knee joint represents a significant determinant of athletic performance and injury prevention; however, its relationship with explosive performance in young female athletes remains insufficiently explored. The aim of the study was to analyze the relationships between isokinetic strength [...] Read more.

Background: Isokinetic strength of the knee joint represents a significant determinant of athletic performance and injury prevention; however, its relationship with explosive performance in young female athletes remains insufficiently explored. The aim of the study was to analyze the relationships between isokinetic strength of the knee joint at different angular velocities and explosive jumping performance in young female athletes. Methods: The research sample consisted of 13 young female athletes enrolled in sport-oriented educational programs specializing in athletics. Explosive lower-limb power was assessed using performance tests for countermovement jump (CMJ), countermovement jump free arms (CMJ FAs) and squat jump (SJ) administered with the Chronojump system. Isokinetic strength of the knee flexors and extensors was assessed using the Humac Norm dynamometer in the concentric mode at angular velocities of 60°/s, 180°/s, and 300°/s. Peak torque, the ipsilateral H:Q ratio, and bilateral asymmetries were evaluated. Pearson’s correlation coefficient was used to analyze the relationships between the investigated parameters. Results: The strongest relationships with explosive performance were observed for hamstring strength at an angular velocity of 180°/s, where significant high correlations were identified with performance in the CMJ (r = 0.693), CMJ FA (r = 0.754), and SJ (r = 0.713). In contrast, quadriceps strength demonstrated predominantly low to moderate associations with jumping performance, while no significant correlations were confirmed at an angular velocity of 300°/s. Bilateral asymmetries of the knee extensors and flexors were generally low, ranging approximately between 7 and 10%, whereas the values of the ipsilateral H:Q ratio were within the physiological range of approximately 50–55%. Conclusions: The results suggest that the ability to generate force at higher contraction velocities, particularly in the hamstrings, is significantly associated with explosive performance in young female athletes. At the same time, isokinetic strength assessment appears to be an appropriate tool for evaluating muscular strength, muscle balance, and potential asymmetries in youth sports. However, explosive performance cannot be explained solely by the level of maximal muscular strength, but rather by a complex interaction of neuromuscular and biomechanical factors. Full article

(This article belongs to the Special Issue Innovative Approaches in Monitoring Individual Sports)

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16 pages, 1453 KB

Open AccessArticle

Between Aesthetics and Health: Disordered Eating, Exercise Addiction, and Body Image in Competitive Bodybuilders

by Federica Moro, Irene Cruccolini, Mario Mauro, Natascia Rinaldo, Emanuela Gualdi-Russo, Luciana Zaccagni and Stefania Toselli

J. Funct. Morphol. Kinesiol. 2026, 11(2), 236; https://doi.org/10.3390/jfmk11020236 (registering DOI) - 13 Jun 2026

Abstract

Objectives: To examine disordered eating behaviors, orthorexic tendencies, binge-eating episodes, attitudes toward exercise, perceived hormone-related symptoms and body image perception among competitive bodybuilders across different levels of competitive experience. Methods: In this cross-sectional study, 60 competitive bodybuilders (29 men, 31 women) [...] Read more.

Objectives: To examine disordered eating behaviors, orthorexic tendencies, binge-eating episodes, attitudes toward exercise, perceived hormone-related symptoms and body image perception among competitive bodybuilders across different levels of competitive experience. Methods: In this cross-sectional study, 60 competitive bodybuilders (29 men, 31 women) completed an anonymous online questionnaire. The survey evaluated demographic characteristics, coaching and training management, phase-specific symptoms (such as libido, sleep, eating behaviors, and menstrual alterations), orthorexic tendencies, exercise addiction, and body-image perception. Results: Both sexes reported reduced libido, increased hunger, and sleep disturbances, along with frequent weight monitoring and common binge-eating episodes. Moreover, females frequently reported menstrual irregularities. ORTO-15 scores indicated a potential risk of orthorexia nervosa, while EAI-3 scores suggested a risk of exercise addiction in novice females and advanced males, with differences in mood regulation and guilt across sex and experience. Males showed higher perceived and ideal muscle mass, whereas females reported higher perceived body fat and a preference for leaner physiques. Conclusions: Competitive bodybuilders of both sexes exhibit post-competition binge eating, mood- and appearance-driven exercise behaviors, and pronounced body-image concerns. Screening, education on energy availability, structured post-competition support, and health-focused coaching are recommended to prevent the progression from sport-specific practices to clinical pathology. Full article

(This article belongs to the Special Issue Advances in Kinanthropometry: Techniques and Applications in Sports and Health, 2nd Edition)

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17 pages, 722 KB

Open AccessArticle

Acute Autonomic and Perceptual Responses to Resistance Training Performed With and Without Blood Flow Restriction

by Paulo H. da Silva Steiger, Tiago A. F. Almeida, Danilo A. Massini, Gabriel de Souza Zanini, David Michel de Oliveira, Víctor Hernández-Beltrán, José M. Gamonales, Mário C. Espada, Dalton M. Pessôa Filho, Filho and Anderson Geremias Macedo

J. Funct. Morphol. Kinesiol. 2026, 11(2), 235; https://doi.org/10.3390/jfmk11020235 (registering DOI) - 12 Jun 2026

Abstract

Objectives: This study aimed to compare the acute effects of high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and low-intensity resistance training with blood flow restriction (LIRT-BFR) on heart rate variability (HRV), rating of perceived exertion (RPE), total load (kg), and number of [...] Read more.

Objectives: This study aimed to compare the acute effects of high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and low-intensity resistance training with blood flow restriction (LIRT-BFR) on heart rate variability (HRV), rating of perceived exertion (RPE), total load (kg), and number of repetitions in young trained men. Methods: Thirteen volunteers (21.5 ± 1.6 years; 178.2 ± 8.0 cm; 75.7 ± 8.0 kg) performed three training sessions with six upper- and lower-limb exercises in repetition-to-failure mode. HIRT was performed at 70% 1RM, four sets and 90 s of rest; LIRT at 30% 1RM, four sets and 30 s of rest; and LIRT-BFR at 30% 1RM, four sets, 30 s of rest, and cuff pressure at 80 mmHg. The rest interval between training sessions was 72 h. Results: Total load was higher during LIRT compared with LIRT-BFR (p < 0.05), with no significant difference compared with HIRT (p > 0.05). The number of repetitions was greater in LIRT than in HIRT (p < 0.05), with no significant difference compared with LIRT-BFR (p > 0.05). RPE was lower in LIRT compared with HIRT and LIRT-BFR (p < 0.05). Time-domain parameters SDNN significantly decreased across all protocols (p < 0.001), whereas RMSSD showed no differences. Frequency-domain components (LFnu, HFnu, and LF/HF) showed no significant differences. Conclusions: LIRT elicited lower perceived exertion compared with HIRT and LIRT-BFR and higher repetition performance, whereas LIRT-BFR, despite showing similar autonomic responses, produced greater perceptual stress, resembling that of HIRT. Full article

(This article belongs to the Special Issue Physical Activity for Optimal Health: 2nd Edition)

6 pages, 206 KB

Open AccessEditorial

Special Issue “Perspectives and Challenges in Sports Medicine for Combat Sports”

by Robert Trybulski

J. Funct. Morphol. Kinesiol. 2026, 11(2), 234; https://doi.org/10.3390/jfmk11020234 - 9 Jun 2026

Abstract

Combat sports occupy a distinctive position within sports medicine [...] Full article

(This article belongs to the Special Issue Perspectives and Challenges in Sports Medicine for Combat Sports)

17 pages, 606 KB

Open AccessReview

Timing Matters: Early Versus Delayed Rehabilitation After Total Knee Arthroplasty and Its Impact on Functional Recovery—A Systematic Review

by Félix Menéndez-Vega, Sandra Núñez-Rodríguez, Jerónimo Javier González-Bernal, Jessica Fernández-Solana, Pedro Aparicio de Águeda and Mirian Santamaría-Peláez

J. Funct. Morphol. Kinesiol. 2026, 11(2), 233; https://doi.org/10.3390/jfmk11020233 - 9 Jun 2026

Abstract

Background: Total knee arthroplasty (TKA) is widely used to treat advanced knee osteoarthritis, yet the optimal timing for initiating postoperative rehabilitation remains unclear, particularly regarding its impact on short- and long-term functional outcomes. Objective: This study aimed to systematically review and compare earlier [...] Read more.

Background: Total knee arthroplasty (TKA) is widely used to treat advanced knee osteoarthritis, yet the optimal timing for initiating postoperative rehabilitation remains unclear, particularly regarding its impact on short- and long-term functional outcomes. Objective: This study aimed to systematically review and compare earlier versus later initiation of structured postoperative rehabilitation following primary TKA according to the timing definitions used in the available literature of structured postoperative rehabilitation after primary TKA and its effects on functional recovery. Methods: Electronic searches were performed in PubMed, Scopus, Web of Science, and ScienceDirect between January and February 2025. Studies were limited to human participants, published in English or Spanish from 2010 onwards. Eligible studies compared early versus delayed rehabilitation following primary TKA and reported at least one predefined outcome related to pain, patient-reported functional measures, range of motion, muscle strength, performance-based functional tests, or hospital length of stay. Study selection was performed independently by two reviewers, and methodological quality was assessed using the Joanna Briggs Institute critical appraisal tools. Results: A total of 662 records were identified, of which five studies (three randomized controlled trials, one prospective observational study, and one retrospective cohort study), including 185 participants, met the inclusion criteria. Early rehabilitation (typically initiated within the first postoperative hours to days) was associated with reductions in hospital length of stay ranging from approximately 1 to 2 days, lower early postoperative pain scores, greater short-term knee flexion gains, and improved early muscle strength compared with delayed rehabilitation protocols. However, no consistent differences were observed in medium- and long-term patient-reported functional outcomes across studies. No increase in postoperative complications was reported. Conclusions: Early initiation of rehabilitation after TKA appears safe and may enhance short-term recovery outcomes. However, no consistent long-term functional differences were observed between earlier and later rehabilitation initiation across the included studies. Further high-quality research with standardized definitions and long-term follow-up is required. Full article

(This article belongs to the Special Issue Advances in Hip and Knee Arthroplasty)

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15 pages, 2431 KB

Open AccessArticle

Comparison of Unilateral, Asymmetric and Traditional Bilateral Resistance Training in Untrained Women: A Pilot and Proof-of-Concept Study

by Atle Hole Saeterbakken, Terese Berger Henriksen, Benedikte Soeviknes Gideonsen, Vidar Andersen, Nicolay Stien, Goran Paulsen and Tom Erik Jorung Solstad

J. Funct. Morphol. Kinesiol. 2026, 11(2), 232; https://doi.org/10.3390/jfmk11020232 - 8 Jun 2026

Abstract

Background: Both unilateral and asymmetric loading have been used to increase training specificity and create over-load in a target limb to reduce inter-limb asymmetries. The aim of the study was to compare the effects of conducting either unilateral- or asymmetric-loaded resistance training with [...] Read more.

Background: Both unilateral and asymmetric loading have been used to increase training specificity and create over-load in a target limb to reduce inter-limb asymmetries. The aim of the study was to compare the effects of conducting either unilateral- or asymmetric-loaded resistance training with traditional bilateral resistance training on maximal dynamic and isometric strength in untrained women. Methods: Thirty-four women not conducting regular resistance training were randomized into unilateral (UNI), bilateral (BIL) or asymmetric (ASY) upper-body resistance training (2–3·wk⁻¹, 10 wk, 24 sessions in total). UNI conducted all exercises unilaterally (one arm at a time), BIL conducted all exercises bilaterally (both arms), and ASY added 10% of the total load to the non-dominant side. Maximal strength was tested in chest press, seated row (1-RM and MVC in both), and pallof press (only MVC). Results: At post-test, BIL demonstrated greater bilateral 1 RM strength than ASY (p = 0.017, d = 1.25) in chest press, while UNI demonstrated greater 1 RM strength in the dominant side than ASY (p = 0.006, d = 1.45). For the other strength tests, no differences were found between groups in chest press (p = 0.068–0.481), seated row (p = 0.091–0.591) or MVC peak force for both chest press and seated row (p > 0.05). All groups demonstrated pre–post improvements for all measurements in chest press (p < 0.05) and seated row (p < 0.05), but only ASY demonstrated improvements in pallof press on the non-dominant side. Conclusions: Compared to traditional bilateral training, unilateral resistance training did not result in similar effects on dynamic or isometric strength. Asymmetric resistance training demonstrated a lower change in chest press strength on the bilateral and dominant sides compared to the other groups. Full article

(This article belongs to the Special Issue 10th Anniversary of JFMK: Advances in Athletic Training and Human Performance)

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17 pages, 287 KB

Open AccessArticle

Glycemic Risk Across Exercise Modalities in Adults with Type 1 Diabetes Using Continuous Glucose Monitoring and Wearable Sensors: A Prospective Cohort Study

by Dimna Zoila Alfaro Quezada, Paul César Velásquez Porras, Alicia Olinda Neyra Aranda, Henri Emmanuel López Gómez, Roberto Carlos Dávila-Morán, Vilma Luz Aparicio-Salas, Zoraida Loaiza-Ortiz, Lupe Marilu Huanca Rojas, Digmer Pablo Riquez Livia, Lindomira Castro Llaja and Liliana Inés Romero Núñez

J. Funct. Morphol. Kinesiol. 2026, 11(2), 231; https://doi.org/10.3390/jfmk11020231 - 8 Jun 2026

Abstract

Background: Exercise provides important health benefits for adults with type 1 diabetes; however, it remains associated with substantial glycemic instability that may vary according to exercise modality, intensity, duration, and clinical context. Continuous glucose monitoring (CGM) and wearable sensors offer an opportunity [...] Read more.

Background: Exercise provides important health benefits for adults with type 1 diabetes; however, it remains associated with substantial glycemic instability that may vary according to exercise modality, intensity, duration, and clinical context. Continuous glucose monitoring (CGM) and wearable sensors offer an opportunity to characterize exercise-related glycemic responses under real-world conditions, yet prospective free-living data remain limited. Objective: This study aimed to evaluate glycemic risk across exercise modalities in adults with type 1 diabetes using CGM and wearable sensors in a real-world prospective cohort. Methods: This prospective cohort study was conducted under free-living conditions in 120 adults with type 1 diabetes. Participants were followed during habitual exercise using CGM, wearable sensor data, and session-level exercise classification. A total of 1568 valid exercise sessions were analyzed and categorized as aerobic, resistance, interval-based, or mixed exercise. The primary outcomes were immediate glucose change and time below range during exercise and within 6 h post-exercise. Secondary outcomes included severe biochemical hypoglycemia, time in range, time above range, glycemic variability, delayed hypoglycemia, nocturnal hypoglycemia, and rescue carbohydrate intake. Results: Glycemic risk differed across exercise modalities. Aerobic exercise was associated with the greatest immediate glucose decline, the highest time below range, the highest frequency of delayed post-exercise hypoglycemia, and the greatest need for rescue carbohydrate intake. Resistance exercise showed the most favorable acute glycemic profile, whereas interval-based and mixed exercise showed intermediate patterns. The associations between exercise modality and glycemic risk were modified by pre-exercise glucose level, time of day, and insulin delivery modality. Sensitivity analyses were consistent with the primary findings. Conclusions: In adults with type 1 diabetes monitored under real-world conditions, glycemic risk varies meaningfully across exercise modalities and is further shaped by clinically relevant contextual factors. These findings support a more individualized interpretation of exercise-related glycemic responses using CGM and wearable-derived data. Full article

(This article belongs to the Special Issue Physical Activity and Exercise for the Management of Diabetes)

14 pages, 1504 KB

Open AccessArticle

Bone Mass and Sexual Dimorphism in Clarke’s Angle: A Multivariate Regression Approach to the Medial Longitudinal Arch in University Students

by Donalds Steven Guali, Victor Manuel Piamba Ome, Armando Monterrosa-Quintero, Boryi A. Becerra-Patiño, Luis Gabriel Rangel Caballero and Adrián De la Rosa

J. Funct. Morphol. Kinesiol. 2026, 11(2), 230; https://doi.org/10.3390/jfmk11020230 - 6 Jun 2026

Abstract

Background: Flattening of the medial longitudinal arch is traditionally attributed to excess body weight and Body Mass Index (BMI). However, controversy exists regarding whether adiposity or skeletal structure drives this biomechanical alteration, and which podometric index best detects it. Methods: A cross-sectional study [...] Read more.

Background: Flattening of the medial longitudinal arch is traditionally attributed to excess body weight and Body Mass Index (BMI). However, controversy exists regarding whether adiposity or skeletal structure drives this biomechanical alteration, and which podometric index best detects it. Methods: A cross-sectional study evaluated 99 healthy university students (50 males, 49 females). Body composition was assessed via a four-component model. Plantar footprints were captured using 4K digital podoscopy and analyzed with five morphometric indices. Arch predictors were identified using multivariate regression models (Elastic Net regression) and Generalized Additive Models (GAMs). Results: Only Clarke’s Angle detected significant sexual dimorphism, showing structurally higher arches in females (50.28° ± 7.14) than in males (41.82° ± 11.20; p < 0.001). Multivariate analysis revealed bone mass as the dominant structural predictor, exerting a non-linear negative association with the arch profile, which stabilizes beyond 12 kg. BMI was not a significant predictor, whereas body fat percentage showed a modest positive association. Conclusions: Plantar arch morphology is strongly associated with skeletal load (anthropometrically estimated bone mass) rather than adiposity or BMI. Within this specific cohort, Clarke’s Angle emerged as a highly sensitive instrument for characterizing sexual dimorphism. Clinical assessments diagnosing functional flatfoot should prioritize underlying bone structure over BMI, particularly when evaluating a healthy and physically active university population. Future studies incorporating DXA or radiographic validation are needed to confirm these anthropometric findings. Full article

(This article belongs to the Section Functional Anatomy and Musculoskeletal System)

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24 pages, 668 KB

Open AccessReview

Motorist’s Disorientation Syndrome—A Narrative Review

by Georges Dumas, Pierre Denise, Art Mallinson, Enrico Armato, Hannes Petersen and Philippe Perrin

J. Funct. Morphol. Kinesiol. 2026, 11(2), 229; https://doi.org/10.3390/jfmk11020229 - 3 Jun 2026

Abstract

Motorist’s disorientation syndrome (MDS) is seen in 1 to 5% of patients in a tertiary neurotology clinic and remains an underdiagnosed pathology. It was first described in 1985 by Page & Gresty, using the term “visual vertigo”. Patients described sensations of veering or [...] Read more.

Motorist’s disorientation syndrome (MDS) is seen in 1 to 5% of patients in a tertiary neurotology clinic and remains an underdiagnosed pathology. It was first described in 1985 by Page & Gresty, using the term “visual vertigo”. Patients described sensations of veering or turning over while driving an automobile when visual input was restricted. This was exacerbated at high speeds, on winding roads, going down hills, or when overtaken by a vehicle. All patients in this initial study had peripheral or central neurotological abnormalities and showed exaggerated responses during optokinetic stimulation. Some sufferers considered giving up driving. The first aims of this narrative review were to delineate the symptoms of MDS as detailed in the literature, to outline precipitating situations and to discuss associated pathologies such as anxiety. The second aim was to differentiate MDS from similar syndromes, such as persistent postural-perceptual dizziness (PPPD) and motion sickness (MS). In addition, we looked at the role of vestibular assessments and discussed the involvement of the otolith organs and semicircular canals. In this review, eight publications were analyzed. MDS is related to a visual-vestibular or a visio-visual conflict and occurs in drivers (both males and females). It is associated with anxiety in 17–39% of cases. Mild vestibular-test abnormalities or exaggerated response to opto-kinetic stimulations are seen in 60–100% of cases. Between 50 and 62% of patients have a migraine history. Convergence and strabismic problems are also often seen. Symptoms usually settle after 6 ± 4 years but can persist for longer in females. MDS is multifactorial, and similar to certain forms of PPPD but different than MS. Its pathophysiology is still in question, and we support the role of the velocity storage integrator as a recent hypothesis. Treatment includes vestibular rehabilitation, virtual reality, cognitive behavioral therapies and orthoptic sessions, and the results are promising. The authors also strongly feel that future research on clarifying MDS pathology should study a wider scope of vestibular assessments to evaluate semicircular canal/otolithic function, as well as the vestibulo-ocular reflex, analyze optokinetic nystagmus time constant, and perform a systematic orthoptic examination. Full article

(This article belongs to the Special Issue Postural Control in Neurological and Musculoskeletal Disorders)

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10 pages, 2957 KB

Open AccessArticle

Comparison of Arch Index Derived from Optical Pedography and Barometric Platform in Children: A Method Agreement Study

by Miloslav Gajdoš, Jakub Čuj, Katarína Hnatová, Wioletta Mikuľáková and Lucia Demjanovič Kendrová

J. Funct. Morphol. Kinesiol. 2026, 11(2), 228; https://doi.org/10.3390/jfmk11020228 - 3 Jun 2026

Abstract

Objectives: The Arch Index (AI) is commonly used to assess medial longitudinal arch morphology; however, values obtained using different measurement technologies may not be interchangeable. This study aimed to compare AI values derived from optical pedography and a barometric platform during bilateral static [...] Read more.

Objectives: The Arch Index (AI) is commonly used to assess medial longitudinal arch morphology; however, values obtained using different measurement technologies may not be interchangeable. This study aimed to compare AI values derived from optical pedography and a barometric platform during bilateral static stance assessment in children and to evaluate their agreement. Methods: Thirty-eight healthy children aged 5–10 years underwent standardized bilateral static foot assessment. AI was calculated using identical segmentation and formula for both systems. Paired t-tests, Pearson correlation, intraclass correlation coefficient, and Bland–Altman analysis were used to assess agreement between methods. Results: Optical pedography produced significantly higher AI values than barometric assessment for both the left (0.284 ± 0.055 vs. 0.188 ± 0.092) and right foot (0.286 ± 0.048 vs. 0.169 ± 0.072; p < 0.001). Agreement between methods was moderate (ICC = 0.494–0.581), with wide limits of agreement. Inter-method differences increased with age. Conclusions: AI values obtained from optical pedography and barometric platforms are not interchangeable in children. Consistent use of a single measurement technology is recommended in pediatric assessment to avoid misinterpretation of developmental changes. Full article

(This article belongs to the Special Issue Advances in Gait Analysis and Lower Limb Movement Mechanics)

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13 pages, 11590 KB

Open AccessArticle

Effects of Oxygen–Ozone Therapy and Physiotherapy on Functioning in Patients with Chronic Non-Specific Neck Pain: A Prospective Double-Arm Pilot Study

by Alessandro de Sire, Andrea Parente, Andrea Demeco, Emanuele Prestifilippo, Martina Cocco, Stefano Fasano, Klemen Grabljevec, Umile Giuseppe Longo, Nicola Marotta and Antonio Ammendolia

J. Funct. Morphol. Kinesiol. 2026, 11(2), 227; https://doi.org/10.3390/jfmk11020227 - 3 Jun 2026

Abstract

Objectives: This study aimed to evaluate the effects of a combined treatment consisting of O₂O₃ injections and McKenzie-based physiotherapy exercises, compared to a Control group treated with O₂O₃ injections and a Back School physiotherapy program, in [...] Read more.

Objectives: This study aimed to evaluate the effects of a combined treatment consisting of O₂O₃ injections and McKenzie-based physiotherapy exercises, compared to a Control group treated with O₂O₃ injections and a Back School physiotherapy program, in reducing pain and disability in individuals with chronic non-specific neck pain. Methods: In this prospective double-arm pilot study, patients with chronic non-specific neck pain and a Numerical Rating Scale (NRS) > 4 were enrolled. All patients received eight weekly sessions of O₂O₃ injections (10 μg/mL, 10 mL total, and 2 mL bilaterally into the cervical paravertebral muscles). Patients were then randomly assigned (1:1 ratio) to either an experimental group receiving McKenzie physiotherapy or a Control group undergoing Back School techniques, with five sessions per week over two weeks. Outcome measures included the Neck Disability Index (NDI), NRS, EuroQol-5D-3L (EQ5D3L), and EuroQol Visual Analog Scale (EQ-VAS). Results: A total of 41 patients were included and divided into two groups: Back School (n = 21; mean age: 63.9 ± 13.4 years) and McKenzie (n = 20; mean age: of 57.3 ± 12.9 years). Both groups showed significant improvement in NDI, NRS, EQ5D3L, and EQ-VAS following the O₂O₃ injection cycle (∆T0–T1 p < 0.001). The subsequent addition of physical therapy led to further improvements across all outcomes in both groups (∆T1–T2 p < 0.001), with the McKenzie group showing slightly greater benefits, despite the lack of significant differences. Conclusions: This study demonstrated the effects of combining O₂O₃ injections with either McKenzie or Back School therapy in improving pain, disability, and quality of life in patients with chronic non-specific neck pain. Full article

(This article belongs to the Section Functional Anatomy and Musculoskeletal System)

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12 pages, 1443 KB

Open AccessArticle

Time-Dependent Endurance Exercise Improves Metabolic Health Through Circadian Rhythm Regulation in Mice

by Yanqing Zhou, Qianyun Cheng, Zuoqing Yan, Chao Lu and Bingxuan Hua

J. Funct. Morphol. Kinesiol. 2026, 11(2), 226; https://doi.org/10.3390/jfmk11020226 - 1 Jun 2026

Abstract

Objectives: Circadian rhythms regulate key physiological processes, including metabolism and energy balance. Emerging evidence suggests that the timing of physical activity may influence metabolic outcomes. However, how the timing of endurance exercise impacts long-term metabolic health and the role of the circadian [...] Read more.

Objectives: Circadian rhythms regulate key physiological processes, including metabolism and energy balance. Emerging evidence suggests that the timing of physical activity may influence metabolic outcomes. However, how the timing of endurance exercise impacts long-term metabolic health and the role of the circadian clock in this process remain unclear. This study aimed to investigate whether time-dependent endurance exercise improves metabolic health via circadian rhythm regulation. Methods: A 12-week endurance exercise protocol was established using wild-type (WT) and circadian-disrupted Clock^Δ19 mice. Mice were assigned to exercise at Zeitgeber time 0 (ZT0) or Zeitgeber time 0 (ZT12), or to sedentary controls. Assessments included rotarod fatigue test, body weight, epididymal fat ratio, fasting blood glucose, serum triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-esterified fatty acids (NEFA), intraperitoneal glucose tolerance test (IPGTT), and insulin tolerance test (ITT). Results: Clock^Δ19 mice exhibited circadian phase-dependent fatigue susceptibility on the rotarod, particularly at ZT0. Both exercised Clock^Δ19 groups (ZT0 and ZT12) showed significant weight reduction compared to sedentary controls, indicating that endurance exercise may counteracts circadian disruption-induced weight gain independent of timing. In WT mice, evening exercise (ZT12) led to enhanced lipid regulation and better glucose tolerance. These time-dependent benefits were absent in Clock^Δ19 mutants, demonstrating that the full metabolic advantages of exercise require a functional circadian clock. Notably, endurance training also partially restored serum HDL-C levels in Clock^Δ19 mice, suggesting compensatory metabolic responses. Conclusions: Aligning endurance exercise with the body’s internal clock provides greater metabolic benefits than untimed exercise. The circadian clock is essential for time-dependent improvements in glucose and lipid metabolism, although some beneficial effects occur independently of a functional clock. Full article

(This article belongs to the Special Issue Advances in Physiology of Training—3rd Edition)

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20 pages, 6684 KB

Open AccessArticle

The Strengthening of Quadriceps, Abductors, and External Rotator Muscles of the Hip to Alter Axial Alignment of the Lower Limbs in University Students with Patellofemoral Pain Syndrome: A Prospective Cohort Study

by Raphael Augusto Gir de Carvalho, Bianca Benelli Pizzolato, Guilherme Pasqualin Afonso de Souza, Evanil Minussi Filho, Gustavo Fonseca Lemos Calixto, Ewerton Alexandre Galdeano, Mariana Mattar Sampaio Madureira, Waldinei Merces Rodrigues, Marcelo Rodrigues da Cunha, Eduardo Gomes Machado, Fernando Bento Cunha, Rogerio Leone Buchaim and Marcelo de Azevedo Souza Munhoz

J. Funct. Morphol. Kinesiol. 2026, 11(2), 225; https://doi.org/10.3390/jfmk11020225 - 1 Jun 2026

Abstract

Background: Proximal lower-extremity muscle strengthening is an important conservative intervention for patellofemoral pain syndrome (PFPS), as these muscle groups play critical roles in femoral stabilization and knee valgus control. However, evidence remains limited regarding the effectiveness of muscle strengthening in improving lower-extremity [...] Read more.

Background: Proximal lower-extremity muscle strengthening is an important conservative intervention for patellofemoral pain syndrome (PFPS), as these muscle groups play critical roles in femoral stabilization and knee valgus control. However, evidence remains limited regarding the effectiveness of muscle strengthening in improving lower-extremity axial alignment through modulation of femoral neck anteversion, femoral internal rotation, and tibial external rotation. Therefore, the present study aimed to determine whether a strengthening protocol targeting the quadriceps and hip external rotator and hip abductor muscles could improve knee alignment and reduce bone torsion in young adults with patellofemoral pain syndrome. Methods: This prospective interventional cohort study implemented a muscle strengthening protocol in ten university students with PFPS. Outcomes included femoral neck anteversion angle (FNA), tibial tubercle–trochlear groove distance (TT–TG), tibial external torsion angle (TET), and the knee Q-angle, assessed via 3D reconstruction of computed tomography (3D-CT) images. Pre- and post-intervention data were analyzed using the Shapiro-Wilk test for normality and repeated-measures ANOVA (p < 0.05; 95% confidence interval). Results: Muscle strengthening improved lower-limb axial alignment, with reductions observed across all measures post-intervention. Mean changes were 0.68 ± 1.26° for FNA (p = 0.0626); 1.51 ± 0.97 mm for TT–TG (p = 0.0001); 1.38 ± 3.36° for TET (p = 0.2231); and 1.14 ± 1.52° for the Q-angle. Statistically significant improvements were observed for TT–TG and the Q-angle. Conclusions: Proximal muscle strengthening improved knee valgus and axial lower-limb alignment, as evidenced by significant reductions in Q angle and TT–TG distance. Reductions in femoral neck anteversion (FNA) and tibial external torsion angle (TET) were observed. However, these differences were not statistically significant. These findings support muscle strengthening as a noninvasive strategy for improving lower-limb alignment in individuals with patellofemoral pain syndrome. Full article

(This article belongs to the Special Issue Anatomy and Physiology of Adapted Physical Activity: Enhancing Health and Performance)

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16 pages, 1564 KB

Open AccessArticle

Effectiveness of Proprioceptive Neuromuscular Facilitation Compared with Standardized Exercise-Based Physiotherapy for Chronic Shoulder Pain Treated with Ultrasound-Guided Corticosteroid Injections: A Randomized Controlled Trial

by Alessandro de Sire, Andrea Demeco, Emanuele Prestifilippo, Rita Ilaria De Socio, Marco Mazzei, Annunziata Filippo, Stefano Fasano, Kristian Efremov, Nicola Marotta and Antonio Ammendolia

J. Funct. Morphol. Kinesiol. 2026, 11(2), 224; https://doi.org/10.3390/jfmk11020224 - 31 May 2026

Abstract

Background: Chronic shoulder pain associated with subacromial bursitis is a common clinical condition characterized by pain and functional limitation, factors that contribute significantly to chronic morbidity for the patient. The combination of ultrasound-guided corticosteroid injections and physical therapy may improve clinical outcomes. [...] Read more.

Background: Chronic shoulder pain associated with subacromial bursitis is a common clinical condition characterized by pain and functional limitation, factors that contribute significantly to chronic morbidity for the patient. The combination of ultrasound-guided corticosteroid injections and physical therapy may improve clinical outcomes. This study compared the effectiveness of Proprioceptive Neuromuscular Facilitation and standardized exercise-based physiotherapy after a common protocol of ultrasound-guided corticosteroid injections in patients with chronic shoulder pain associated with subacromial bursitis. Methods: A randomized controlled pilot study was conducted on adult patients with chronic shoulder pain (NRS ≥ 4), who received 3 weekly intra-bursal ultrasound-guided injections of corticosteroids and local anesthetic, followed by either 10 sessions of PNF or standardized exercise-based physiotherapy. The primary outcome was pain intensity assessed by NRS. Secondary outcomes included DASH, EQ-5D, EQ-VAS, and ROM, assessed at baseline, 2 weeks, 4 weeks, 12 weeks, and 24 weeks. Results: The PNF group showed greater improvements in selected outcomes and at some follow-up time points, particularly for functional measures and shoulder ROM. However, between-group differences were not consistent across all predefined outcomes. Conclusions: Both PNF-based rehabilitation and standardized exercise-based physiotherapy may improve clinical outcomes after ultrasound-guided corticosteroid injection in patients with subacromial bursitis. However, the added value of PNF appears limited to selected outcomes and time points, and its superiority over standardized physiotherapy cannot be definitively established. Full article

(This article belongs to the Special Issue Exercise and Movement Interventions in the Prevention and Treatment of Chronic Pain)

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12 pages, 1011 KB

Open AccessArticle

Triage Assessment of Lateral Ankle Sprain Surgical Risk (TALAR Score): Using Early Red Flags to Predict the Failure of Conservative Management

by Raffaele Vitiello, Antonio Bove, Guglielmo Miele, Andrea De Fazio, Luca Magrini, Marianna Citro, Matteo Turchetta and Fabrizio Forconi

J. Funct. Morphol. Kinesiol. 2026, 11(2), 223; https://doi.org/10.3390/jfmk11020223 - 31 May 2026

Abstract

Background: Functional testing after an ankle sprain may help identify patients who later develop mechanical instability and require surgery. This study aimed to identify early clinical and functional predictors of surgical stabilization for chronic ankle instability (CAI) after acute sprains and to develop [...] Read more.

Background: Functional testing after an ankle sprain may help identify patients who later develop mechanical instability and require surgery. This study aimed to identify early clinical and functional predictors of surgical stabilization for chronic ankle instability (CAI) after acute sprains and to develop a simple composite predictive score (TALAR). Methods: This prospective observational study included 197 patients with acute lateral ankle sprains. Comprehensive clinical and functional assessments, including range of motion (ROM), strength, and pain, were performed two weeks post-injury. The primary outcome was subsequent surgical management for instability within a 24-month follow-up period. Results: Eight patients (4%) ultimately underwent surgical stabilization. Univariable analysis identified three significant predictors of surgical outcome: eversion mobility ≥ 20°, plantar flexor strength ≤ 17 kg, and the presence of pain during dorsiflexion (VAS > 0). These variables were integrated into the 0–3 TALAR (Triage Assessment of Lateral Ankle sprain Surgical Risk) score, which demonstrated promising exploratory discrimination with an AUC of 0.889 (95% CI: 0.799–0.954). An optimal cut-off of ≥2 yielded a sensitivity of 0.875 and a specificity of 0.822. While the baseline surgical risk was 4%, patients with a TALAR score ≥2 had a 17.5% conversion rate to surgery, representing a significantly higher risk (OR: 32.24; p < 0.001). Conclusion: The TALAR score represents a promising exploratory tool for early risk stratification after an acute ankle sprain. As an exploratory study, it highlights that early functional red flags, though formal internal and external validation, along with robust calibration on longer follow-up cohorts, are required before clinical implementation. Full article

(This article belongs to the Special Issue From Acute Trauma to Chronic Instability: Mechanisms, Management, Rehabilitation, and Functional Outcomes)

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14 pages, 975 KB

Open AccessArticle

Effects of Wushu Programs on Lower-Limb Explosive Power in Preschool Children Aged 5–6 Years: A Cluster-Randomized Controlled Trial

by Beibei Luo, Ruoxi Fan, Rui Li, Rongda Wang, Xiaomiao Zheng, Rui Huang, Shuxin Zhang, Yiwei Sun, Zhibei Zhou and Yunya Zhang

J. Funct. Morphol. Kinesiol. 2026, 11(2), 222; https://doi.org/10.3390/jfmk11020222 - 31 May 2026

Abstract

Background: Wushu, a traditional Chinese exercise, has been demonstrated to be effective in promoting lower-limb strength in children. However, studies comparing the effects of different intervention durations on preschool children remain limited. Objectives: The present study examined the short- and long-term effects of [...] Read more.

Background: Wushu, a traditional Chinese exercise, has been demonstrated to be effective in promoting lower-limb strength in children. However, studies comparing the effects of different intervention durations on preschool children remain limited. Objectives: The present study examined the short- and long-term effects of Wushu exercise programs on lower-limb explosive power in preschool children aged 5–6 years. Methods: This study was conducted across two experiments, with separate cohorts of children. The children were randomly assigned to either an intervention (INT) or a control (CON) group based on their Kindergarten classes. In Experiment 1, the INT-1 group (n = 55) completed a 4-week ‘Twelve Zodiac’ Wushu exercise program, which comprised three 30-minute sessions per week, while the CON-1 group (n = 49) participated in construction and carrying-based unstructured free play, which was designed to provide a comparable amount of moderate-to-vigorous physical activity. In Experiment 2, the INT-2 group (n = 57) undertook a 10-week Wushu program, and the CON-2 group (n = 38) engaged in similar activities as CON-1 for a 10-week period. The standing long jump (SLJ) was the primary outcome measure in both experiments. Secondary outcomes included the double-leg continuous jump, 15 m zigzag run, grip strength, sit-and-reach, and anthropometric measurements. In Experiment 2, countermovement jump (CMJ) and squat jump (SJ) heights were also measured using a force plate as additional secondary outcomes. A linear mixed-effects model (LMM) was used to analyze the data. Results: At baseline, no significant outcome measures were observed between CON-1 and INT-1, nor between CON-2 and INT-2. In Experiment 1, SLJ exhibited a significant enhancement in INT-1 in comparison to CON-1 (p = 0.007). The INT-2 in Experiment 2 showed significant improvements compared with CON-2 in the SLJ (p = 0.048), double-leg continuous jump (p = 0.005), and 15 m zigzag run (p = 0.043). A strong correlation was observed between SLJ and 15 m zigzag run time (r = −0.53, p < 0.001), and between double-leg continuous jump time and 15 m zigzag run time (r = 0.56, p < 0.001). Conclusions: The findings of this study indicate that 4-week and 10-week Wushu exercise programs enhance explosive power in the lower limbs of children aged 5–6 years. The 10-week Wushu program improves lower limb coordination and jumping agility. These task-specific adaptations support the value of Wushu interventions for fostering comprehensive lower-limb motor competence in preschoolers. Full article

(This article belongs to the Special Issue Tailoring Physical Activity for the Health and Development of Children and Adolescents)

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10 pages, 622 KB

Open AccessArticle

Getting Stronger Without Moving an Inch: A Randomized Controlled Trial Utilizing Maximal Isometric Co-Contraction

by Danny Lum, Paul Comfort and Dustin J. Oranchuk

J. Funct. Morphol. Kinesiol. 2026, 11(2), 221; https://doi.org/10.3390/jfmk11020221 - 29 May 2026

Abstract

Background: Maximal isometric co-contraction (MICC) of upper-limb muscles enhances strength and size, but its effects on lower-limb function are unknown. The aim of this study was to examine whether MICC training targeting the lower limbs can improve muscular strength and functional performance [...] Read more.

Background: Maximal isometric co-contraction (MICC) of upper-limb muscles enhances strength and size, but its effects on lower-limb function are unknown. The aim of this study was to examine whether MICC training targeting the lower limbs can improve muscular strength and functional performance in sedentary adults. Methods: Twenty sedentary individuals (10 men, 10 women; 48.5 ± 7.5 years; BMI = 24.8 ± 4.2 kg/m²) were randomly assigned to either an experimental (EXP) or control (CON) group. The EXP group performed MICC of the knee flexors and extensors three times per week for four weeks, completing three sets of 5–10 maximal effort 3 s contractions per session. Assessments conducted pre- and post-intervention included the isometric mid-thigh pull (IMTP), 3-m timed up and go (TUG), and 30 s chair stand (CS) tests. Results: Significant time (p < 0.001) and time × group (p < 0.001) effects were found for all outcomes. Compared with CON, the EXP group showed greater improvements in IMTP peak force (p < 0.001, g = 1.80), faster TUG times (p < 0.001, g = 2.73), and more CS repetitions (p < 0.001, g = 3.90). Conclusions: Twelve sessions of MICC training improved maximal strength and functional performance in sedentary adults. This simple, equipment-free method may be particularly useful for individuals with limited access to conventional exercise facilities or supervision. Full article

(This article belongs to the Section Kinesiology and Biomechanics)

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17 pages, 1454 KB

Open AccessArticle

Use Treadmills with Caution: Walking Energy Expenditure and Metabolic Cost Are Elevated Compared to Overground Across Multiple Speeds in Healthy Young Adults

by Sauvik Das Gupta, Kanako Kamishita, Megumi Kondo and Yoshiyuki Kobayashi

J. Funct. Morphol. Kinesiol. 2026, 11(2), 220; https://doi.org/10.3390/jfmk11020220 - 29 May 2026

Abstract

Objectives: Treadmill walking is often employed for tightly controlled gait and energetics research, but growing evidence suggests that treadmill-based metabolic and biomechanical measurements may not directly reflect the ecologically valid mode of overground walking. While many previous studies focused on older adults, [...] Read more.

Objectives: Treadmill walking is often employed for tightly controlled gait and energetics research, but growing evidence suggests that treadmill-based metabolic and biomechanical measurements may not directly reflect the ecologically valid mode of overground walking. While many previous studies focused on older adults, much less is known about how treadmill walking influences gait energetics and spatiotemporal parameters in young healthy adults across matched speeds. We investigated energy expenditure, metabolic cost of walking and spatiotemporal gait parameters in healthy young adults walking overground and on a treadmill at three speeds (slow—1.0, comfortable—1.3, fast—1.5 m/s). Our hypothesis was that at the comfortable speed, treadmill and overground energetics and gait parameters would be comparable. However, at slow and fast speeds, there would be a significant energetic penalty, accompanied by significant differences in spatiotemporal parameters. Methods: Twenty young participants (10 males and 10 females) completed a randomized cross-over walking protocol with a minimum of ten minutes treadmill familiarization at 1.3 m/s. Breath-by-breath oxygen consumption (

\dot{V} O_{2}

) and Respiratory Exchange Ratio were measured using a portable indirect calorimetry system and gait parameters were calculated from Inertial Measurement Units. Gross and net energy expenditures, costs of walking, cadence, average step and stride lengths, and walk ratio were calculated. A three-way mixed ANOVA was used for primary statistical analyses. Results: Treadmill walking was characterized by higher gross and net energy expenditures and metabolic costs (p < 0.001, η_p² = 0.6) across all speeds compared to overground. It was also characterized by faster cadence and shorter average step and stride lengths (p < 0.001, η_p² = 0.9). Additionally, there was an effect of sex (p = 0.01, η_p² = 0.3) on the gait parameters, with females exhibiting a faster cadence and shorter average step and stride lengths than males. Conclusions: Our findings show that treadmill walking imposes a medium-to-large metabolic penalty even in healthy young adults, with compensatory gait adaptations, possibly reflecting increased stabilization demands and altered neuromuscular control strategies. These results underscore the limits of generalizing treadmill derived gait data to overground walking and we caution against the uncritical use of treadmills, especially while trying to understand ecologically relevant human walking mechanics and energetics. Full article

(This article belongs to the Special Issue 10th Anniversary of JFMK: Advances in Kinesiology and Biomechanics)

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23 pages, 1837 KB

Open AccessReview

Effects of Aquatic Therapy on Fatigue, Mobility, Physical Function, and Quality of Life in People with Multiple Sclerosis: A Systematic Review and Meta-Analysis

by Gema Santamaría, Elena Jiménez-Callejo, Noelia Rodríguez López, Luis M. Cacharro, Eduardo Gutiérrez-Abejón, Leticia Sánchez-Valdeón and Diego Fernández-Lázaro

J. Funct. Morphol. Kinesiol. 2026, 11(2), 219; https://doi.org/10.3390/jfmk11020219 - 29 May 2026

Abstract

Background: Aquatic therapy has emerged as a promising rehabilitation strategy for people with multiple sclerosis (MS), potentially improving physical and psychological outcomes through the unique properties of water. The aim of the study was to systematically evaluate the effects of aquatic therapy on [...] Read more.

Background: Aquatic therapy has emerged as a promising rehabilitation strategy for people with multiple sclerosis (MS), potentially improving physical and psychological outcomes through the unique properties of water. The aim of the study was to systematically evaluate the effects of aquatic therapy on fatigue, mobility, physical function, and quality of life (QoL) in people with MS. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. Electronic databases (PubMed, Scopus, Web of Science, PEDro, CINAHL, and Cochrane) were searched from inception to February 2026. Eligible studies included adults with MS undergoing aquatic therapy interventions. Risk of bias and methodological quality was assessed using the Cochrane tool and the PEDro scale, respectively. Effect sizes were calculated as standardized mean differences (SMD) using a random-effects model. Results: Seven randomized controlled trials (RCTs) were included in the review. Meta-analysis demonstrated a large reduction in fatigue (SMD ≈ −1.20), moderate improvements in mobility and physical function (SMD ≈ 0.7), and small-to-moderate improvements in QoL (SMD ≈ 0.45) in favour of aquatic therapy. Heterogeneity ranged from moderate to high depending on the outcome. Qualitative synthesis supported these findings and indicated additional benefits in strength, balance, psychological well-being, and disease-related symptoms. No adverse events were reported. Conclusions: Aquatic therapy may represent a generally well-tolerated and potentially beneficial rehabilitation strategy for improving fatigue, mobility, and QoL in people with MS. However, these findings should be interpreted with caution due to the limited number of included RCTs, relatively small sample sizes, and substantial heterogeneity across interventions and outcome measures. Full article

(This article belongs to the Special Issue 10th Anniversary of JFMK: Advances in Athletic Training and Human Performance)

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Journal of Functional Morphology and Kinesiology

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