Lab
Sports Medical Research Group, Balgrist University Hospital
Institution: University of Zurich
About the lab
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https://www.balgrist.ch/en/research/research-units/research-sports-medicine/
https://www.balgrist.ch/en/research/research-units/research-sports-medicine/
Featured research (155)
Background/Objectives: In recent years, there has been a growing interest in precision nutrition and its potential for disease prevention. Differences in individual responses to diet, especially among populations of different ancestry, have underlined the importance of understanding the effects of genetic variations on nutrient intake (nutrigenomics). Since humans generally cannot synthesize essential vitamins, the maintenance of healthy bodily functions depends on dietary vitamin intake. Understanding the differences in vitamin uptake and metabolism across diverse populations may allow for targeted treatment plans and improved overall health. We assessed the current scientific evidence on genetic variations (such as single-nucleotide polymorphisms (SNPs)) affecting vitamin metabolism in humans. Methods: A systematic literature review of primary studies on genetic variations associated with (personalized) nutrition was conducted. Using key terms related to personalized nutrition, nutrigenomics, SNPs, and genetic variations, three online databases were searched for studies published between 2007 and 2023 that included healthy adult subjects. Only results that were confirmed at least once were included. Study quality was assessed with the Joanna Briggs Institute (JBI) critical appraisal tool. Results: Eighty-six articles were included in this review. Our analysis revealed associations with homocysteine metabolism and B Vitamins, Vitamin D, and components of Vitamin E. Genetic associations with Vitamin D, particularly with the GC gene, were extensively researched and linked to lower 25(OH)D concentrations, with sunlight exposure as a contributing factor. Most variants had a negative effect on homocysteine levels. Additionally, we observed general increases in carotenoid levels in the presence of SNPs, although more research on Selenium and Selenoprotein P concentrations is warranted. No studies on Vitamin C were obtained, indicating an area for further methodological improvement. Ancestry is believed to be a significant factor influencing SNP associations and significance. Conclusions: The current review emphasizes the importance of genetics in targeted disease prevention and health care. Our comprehensive findings may provide healthcare practitioners with reliable information to make recommendations in precision nutrition, specifically vitamin supplementation.
Competitive alpine skiing requires a high level of physical fitness to perform sport-specific manoeuvres and to minimise the risk of injury. The aim of this study was to establish reference values for the maximal anatomical cross-sectional area (ACSAmax) of the individual hamstrings (HAM) and quadriceps (QUAD) muscles as well as for the maximal voluntary torque (MVT) during knee flexion (KF) and knee extension (KE) of female and male elite competitive alpine skiers. Ultrasound and dynamometer data were obtained from a largely overlapping but not identical dataset. The ultrasound data were collected from 33 elite alpine skiers (20 women and 13 men), and the dynamometer data were collected from 35 elite alpine skiers (20 women and 15 men). Compared with female skiers, male skiers presented a significantly greater ACSAmax in the biceps femoris short head (BFsh), biceps femoris long head (BFlh), and semitendinosus (ST) muscles, as well as in the entire HAM muscle group. The ACSAmax of the semimembranosus (SM) did not differ significantly between the two sexes. Compared with female skiers, male skiers presented significantly greater ACSAmax values in the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) and entire QUAD muscle groups. At VI, there was no significant difference in the ACSAmax between the two sexes. Compared with male skiers, female skiers had a significantly greater proportional SM ACSAmax. In terms of MVT, male skiers presented greater absolute and relative values than females did. There were no differences in the MVT/ACSAmax between the sexes. Neither the HAM/QUAD ACSAmax ratio nor the KF/KE MVT ratio differed between the sexes. The present study provides normative values for the muscle size and strength of the HAM and QUAD muscles of elite competitive alpine skiers. These values can be used as benchmarks for youth alpine skiers striving for the elite level. An interesting finding of the present study was that female skiers had a greater proportional ACSAmax of the SM, as this may be relevant in anterior cruciate ligament injury prevention given the function of tibia internal rotation.
Background:
Overuse-related intersegmental abnormalities in the spine of competitive alpine skiers are common findings. However, longitudinal changes in intersegmental abnormalities and symptoms throughout adolescence have not been assessed.
Purpose:
To longitudinally assess and compare overuse-related spinal intersegmental abnormalities in adolescent competitive alpine skiers over 48 months and to compare magnetic resonance imaging (MRI) findings in asymptomatic and symptomatic skiers.
Study Design:
Case series; Level of evidence, 4.
Methods:
Adolescent competitive alpine skiers were prospectively recruited between November 2108 and February 2019 and underwent 3-T MRI of the lumbar spine at baseline and after 48 months. All MRI scans were assessed for intersegmental changes of the intervertebral disk, vertebral body, and facet joints. At both time points, athletes’ low back pain (LBP) symptoms were assessed via retrospective interviews relating to the 12-month period before the MRI study. Athletes were classified as symptomatic if at least 1 substantial episode of health problems related to back overuse had occurred in the 12 months before the MRI examination. The Wilcoxon signed-rank test and Pearson chi-square test were used to compare the measurements.
Results:
A total of 63 athletes (mean age at follow-up, 19.6 ± 1.2 years; 25 female) were included in the study. A significant increase in LBP affecting training and competition was observed at follow-up, with only 2 athletes reporting a history of spinal trauma (baseline, n = 13; follow-up, n = 20; P = .04). Of the athletes with LBP (n = 27), 59% (n = 16) reported recurrent LBP, 15% (n = 4) reported permanent LBP, and 26% (n = 7) reported 1-time LBP since baseline. Assessment of intersegmental changes revealed a significant increase in the number of athletes with disk signal reduction (baseline, n = 10; follow-up, n = 21; P = .001), disk bulging (baseline, n = 7; follow-up, n = 19; P = .002), or disk herniation (follow-up, n = 2; P = .04). Overall, intersegmental abnormalities did not correlate with LBP within the last year (P = .53).
Conclusion:
Overuse-related intersegmental abnormalities of the lumbar spine are common in adolescent competitive alpine skiers and are often clinically silent at this age. These abnormalities may persist throughout skeletal maturation and even worsen during adolescence.
Purpose : To investigate the physiological characteristics of freestyle snowboard and freeski athletes and explore potential differences between males and females. Methods : National-team athletes, snowboard (9 males, 21 [2.3] y; 8 females, 20 [4.1] y) and freeski (10 males, 21 [2.1] y; 8 females, 18 [2.2] y), underwent physiological assessments: maximal oxygen uptake ( ; indirect), countermovement-jump height, drop-jump (DJ) height, DJ contact time, reactive strength index, absolute peak force (PF abs ), and relative peak force. Differences were analyzed using multivariate analyses of variance Wilks lambda (Λ) and magnitude with partial-eta squared ( ). Pairwise comparisons and the impact of sex and sport were analyzed with univariate tests, utilizing Cohen d . Results : No physiological differences were found between snowboard and freeski (Wilks Λ = 0.8, P > .251, = .169). Sex differences were observed (Wilks Λ = 0.2, P < .001, ), without an interaction between sex and sport (Λ = 0.8, P > .449, ). For snowboard, sex differences included ( P < .001, d = 1.04), countermovement-jump height ( P < .001, d = 2.5), DJ height ( P < .001, d = 1.45), DJ contact time ( P < .001, d = 0.36), reactive strength index ( P < .001, d = 1.36), front-limb PF abs ( P < .001, d = 1.77), rear-limb PF abs ( P < .001, d = 1.36), front-limb relative PF ( P < .003, d = 0.88), and rear-limb relative PF ( P < .021, d = 0.65). In freeski, differences included ( P = .005, d = 0.81), countermovement-jump height ( P < .001, d = 1.3), DJ height ( P < .001, d = 1.17), DJ contact time ( P < .040, d = 0.54), reactive strength index ( P < .001, d = 1.0), left-limb PF abs ( P < .001, d = 2.2), right-limb PF abs ( P < .001, d = 1.88), left-limb relative PF ( P < .001, d = 1.1), and right-limb relative PF ( P < .001, d = 1.33). Conclusions : Differences between the sexes, rather than between sports, explained the largest variance. A broad concurrent training approach with the aim of developing resilient athletes is likely warranted while acknowledging and adapting to individual needs.
Background: Grip strength is widely used as a surrogate parameter for functional status. The current gold standard, the JAMAR® Hydraulic Dynamometer (JAMAR® Hydraulic), presents challenges for individuals with painful finger joints or low grip strength. Therefore, the objective of this observational study was to assess comparability across the JAMAR® Smart, the Martin Vigorimeter and the gold standard. Additionally, the intrasubject and intersession reliability of all three devices were examined, which are essential for quality control before generating normative data. Methods: Forty healthy participants (aged 37.0 ± 11.3 years) were included, and a subset of 20 participants was randomly selected for retesting. Grip strength testing involved five attempts per measurement device. Results: Intrasubject reliability was excellent (ICC3,1: 0.91–0.97), and a strong correlation (ICC3,1: 0.90–0.98) was found between the first attempt and the best of five as well as between the best of two or three attempts and the best of five, demonstrating robust reliability across multiple measures. Intersession reliability was good to excellent (ICC3,1: 0.85–0.97) across all three devices, which was confirmed by Bland–Altman analysis. The PCC (r) revealed moderate to very strong agreement with the current gold standard JAMAR® Hydraulic (r = 0.68–0.98), with increased differences between the Martin Vigorimeter and the JAMAR® Hydraulic measurements, particularly at low and high values. Conclusions: The proposed devices are suitable for test-retest analysis with 2–3 attempts. Despite high correlations between all three devices, the diverging levels of agreement between the Martin Vigorimeter and the established gold standard warrant caution against using these devices interchangeably.
Keywords: hand strength; validation studies; reproducibility of results; test-retest reliability; physical therapy
Lab head

Department
- Balgrist University Hospital, Department of Orthopaedics
About Jörg Spörri
- Jörg Spörri currently works as Head of Sports Medical Research at Balgrist University Hospital (Department of Orthopaedics, University of Zurich). He and his research group are particularly focusing on protecting the health of elite athletes and developing cutting-edge diagnostic and rehabilitation concepts in sports medicine, from which recreational athletes and orthopaedic patients will ultimately also benefit.