Time-of-Day Effect on Hip Flexibility Associated with the Modified Sit-and- Reach Test in Males

A four-week minimalist shoe walking intervention influences foot posture and balance in young adults-a randomized controlled trial

INTRODUCTION

Minimalist shoes (MS) are beneficial for foot health. The foot is a part of the posterior chain. It is suggested that interventions on the plantar foot sole also affect the upper segments of the body. This study aimed to investigate the local and remote effects along the posterior chain of four weeks of MS walking in recreationally active young adults.

METHODS

28 healthy participants (15 female, 13 male; 25.3 ± 5.3 years; 70.2 ± 11.9 kg; 175.0 ± 7.8 cm) were randomly assigned to a control- or intervention group. The intervention group undertook a four-week incremental MS walking program, which included 3,000 steps/day in the first week, increasing to 5,000 steps/day for the remaining three weeks. The control group walked in their preferred shoe (no MS). We assessed the following parameters in a laboratory at baseline [M1], after the four-week intervention [M2], and after a four-week wash-out period [M3]: Foot parameters (i.e., Foot Posture Index-6, Arch Rigidity Index), static single-leg stance balance, foot-, ankle-, and posterior chain range of motion, and muscle strength of the posterior chain. We fitted multiple hierarchically built mixed models to the data.

RESULTS

In the MS group, the Foot Posture Index (b = -3.72, t(51) = -6.05, p < .001, [-4.94, 2.51]) and balance (b = -17.96, t(49) = -2.56, p = .01, [-31.54, 4.37]) significantly improved from M1 to M2, but not all other parameters (all p >.05). The improvements remained at M3 (Foot Posture Index: b = -1.71, t(51) = -2.73, p = .009, [-4,94,0.48]; balance: b = -15.97, t(49) = -2.25, p = .03, [-29.72, 2.21]).

DISCUSSION

Walking in MS for four weeks might be advantageous for foot health of recreationally active young adults but no chronic remote effects should be expected.

A New Measuring Approach in Assessing Hamstring Flexibility: Reliability, Validity, and Applicability of Isolated Hamstring Flexibility Test

OBJECTIVE

This study was planned to determine the reliability, validity, and applicability of the isolated hamstring flexibility test (IHFT).

DESIGN

A cohort study (diagnosis); level of evidence, 2.

SETTING

It was performed in the research and application laboratory.

PARTICIPANTS

Seventy-five individuals aged 18 to 25 years, selected through simple probability random sampling, with a normal Beighton Horan and Joint Mobility Index scores, and who volunteered to participate, were included for evaluation.

INTERVENTIONS

On then first and third days, participants underwent muscle strength, sit-and-reach test, active knee extension test, IHFT for validity and reliability. Stretching exercises were prescribed as a home program for 31 patients with limited knee extension, and measurements were repeated at the end of the eighth week.

MAIN OUTCOME MEASURES

Sit-and-reach test, active knee extension test, IHFT.

RESULTS

The test-retest reliability was high (intraclass correlation coefficient, 0.993). Our test demonstrated validity when compared in terms of flexibility gained. A significant difference was found between pre-post stretching exercise training in all 3 tests (P < 0.05).

CONCLUSION

It was observed that the IHFT is reliable and applicable in determining hamstring flexibility. Given the absence of another test specifically measuring hamstring flexibility in isolation, its indirect validity was established through analysis with other tests using the gold standard for assessing gains in hamstring flexibility.

The Foam Roll as a Tool to Improve Hamstring Flexibility

Although foam rolling is a common myofascial therapy used to increase range of motion (ROM), research is limited on the effectiveness of foam rolling on soft tissue extensibility. The aim of this study was to determine the effect of a 4-week training period of the foam roll method on hamstring flexibility. Furthermore, the study was designed to compare the effectiveness of the foam roll myofascial release with a conventional contract-relax proprioceptive neuromuscular facilitation (PNF) stretching method and a control group. Forty healthy males (age: 17-47 years) were randomly assigned to a foam roll group (FOAM, n = 13), a contract-relax PNF stretching group (CRPNF, n = 14), or a control group (CG, n = 13). The FOAM group massaged their hamstring muscles with the foam roll 3 times per week for 4 weeks (12 training sessions). The CRPNF group was assigned to 12 sessions of contract-relax PNF stretching. The CG underwent no intervention. Hamstring flexibility (ROM) was measured by a stand-and-reach test before and after the intervention period. Two-way repeated-measures analysis of variance showed a significant global time effect (p < 0.001) and an interaction effect for time × treatment (p = 0.004), demonstrating greater improvements in the FOAM and CRPNF compared with the CG, but no difference between the former. Delta changes from baseline to postintervention in ROM were not related to baseline ROM. The foam roll can be seen as an effective tool to increase hamstring flexibility within 4 weeks. The effects are comparable with the scientifically proven contract-relax PNF stretching method.

Time-of-Day Effects on Psychomotor and Physical Performances in Highly Trained Cyclists

The aim of this study was to examine, in trained young cyclists, whether psychomotor performances were dependent on time of day and fluctuated similarly to changes in athletic performance. 14 highly trained male cyclists ( M age = 17.3 yr., SD = 1.6; M height = 179.0 cm, SD = 0.1; M body weight = 67.4 kg, SD = 4.5) voluntarily took part in 6 test sessions, at 08:30, 10:30, 12:30, 14:30, 16:30 and 18:30. Each test session comprised a maximal-intensity exercise consisting of 2 × 10-sec. sprints (all-out exercise) preceded by an attentional performance test including 4 fields of attention performed in a randomized order at different times throughout the same day, every 2 hr. between 08:30 and 18:30. The main results indicated that attentional and physical performances depended on the time of day, with an improvement in reaction times in phasic alertness, visual scanning, flexibility, Go/No-go, and an increase in maximum power throughout the day. This study shows the daily variations in physical performances and that fluctuations are reflected in psychomotor performances. These findings suggest that cyclists' training sessions cannot be programmed throughout the day without taking into consideration the effects of the time of day, with several practical applications for coaches and athletes.