Presenting semantically related L2 words is a popular method in EFL coursebooks, but the research results on this issue remain inconclusive. Therefore, this study aims to investigate the effects of semantic clustering on Korean young learners’ English vocabulary learning. The study was conducted with 174 primary school students. The subjects were divided into two groups: a semantically related words group (SR) and a semantically unrelated words group (SU). For the six weeks of treatment, the two comparison groups were taught the same 40 vocabulary items in different clusters. The vocabulary test results showed that both vocabulary presentation methods had a positive effect on vocabulary learning. However, the SU group significantly outperformed the SR group. These findings indicate that presenting new L2 words in semantically unrelated sets might be more effective than semantically related sets.

The objective of this study was to determine the duration of maintained calf muscle flexibility gained in young adults with calf muscle tightness, as measured by increases in ankle active and passive dorsiflexion range of motion (DFROM) after three stretching interventions. Twenty subjects (5 men and 15 women) with calf muscle tightness received the following three stretching interventions in one leg (assigned at random): static stretching (SS), eccentric training on stable surface (ETS), and eccentric training on unstable surfaces (ETU). The subjects received all three interventions to the same leg, applied in a random order. Each intervention had a break of at least 24 h in-between, in order to minimize any carryover effect. Each intervention used two types of stretching: with the calf muscle stretched and both knees straight, and with the knee slightly bent in order to maximize the activation of the soleus muscle. All three interventions were performed for 200 seconds. We measured the duration of maintained calf muscle flexibility through active and passive ankle DFROM before intervention, immediately after intervention (time 0), and then 3, 6, 9, 15, and 30 min after intervention. We found a difference in the duration of maintained calf muscle flexibility between the three interventions. In the ETS and ETU interventions, a significant improvement in calf muscle flexibility, both ankle active and passive dorsiflexion ranges of motion (ADFROM and PDFROM), was maintained for 30 min. In the SS intervention, however, ADFROM before 9 min and PDFROM before 6 min were statistically different from the baseline. Our results suggest that ETS and ETU may be more effective than SS for maintaining calfmuscle flexibility in young adults.

The aim of this study was to compare the duration of hamstring flexibility improvement after 3 stretching interventions in people with limited hamstring flexibility. Twenty-two subjects (12 men, 10 women) with limited hamstring flexibility of the dominant leg received 3 stretching interventions— modified dynamic stretching (MDS), hold-relax (HR), and static stretching (SS)—in a random order. All the subjects received all 3 interventions at intervals of at least 24 hours to minimize any carry-over effect. Modified dynamic stretching was applied as a closed kinetic chain exercise in the supine position by using the sling suspension system (Redcord Trainer®). The SS and HR interventions were individually performed in the straight leg raising (SLR) position, and all 3 interventions were performed for 3 minutes. Outcome measures included passive knee extension (PKE) measurements. Five post-test measurements were recorded for all subjects at 3, 6, 9, 15, and 30 minutes after the interventions. MDS was associated with a significant increase in knee extension range of motion even at 30 minutes post-treatment. In contrast, the HR and SS stretching methods showed increased hamstring flexibility for only 6 minutes post-treatment. Improvements in the range of motion of knee extension (indicating enhancement in hamstring flexibility) with MDS were maintained longer than those with the HR and SS interventions. Therefore, MDS may be more effective than the other interventions for maintaining hamstring flexibility.