Nai-Jen Chang

Prof. Nai-Jen Chang

Department of Sports Medicine, Kaohsiung Medical University
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2017 in Journal of Sport Rehabilitation
Verified
Journal Article
Closed access
HSHsuan Su
Hsuan Su
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
Wen-Lan WuWen-Lan Wu
Wen-Lan Wu
Lan-Yuen GuoLan-Yuen Guo
Lan-Yuen Guo
I-Hua ChuI-Hua Chu
I-Hua Chu
Context: Foam rolling has been proposed to improve muscle function, performance, and joint range of motion (ROM). However, whether a foam rolling protocol can be adopted as a warm-up to improve flexibility and muscle strength is unclear.Objectives: To examine and compare the acute effects of foam rolling, static stretching, and dynamic stretching used as part of a warm-up on flexibility and muscle strength of knee flexion and extension.Design: Crossover study.Setting: University research laboratory.Participants: 15 male and 15 female college students (age 21.43 ± 1.48 y, weight 65.13 ± 12.29 kg, height 166.90 ± 6.99 cm).Main Outcome Measures: Isokinetic peak torque was measured during knee extension and flexion at an angular velocity of 60°/second. Flexibility of the quadriceps was assessed by the modified Thomas test, while flexibility of the hamstrings was assessed using the sit-and-reach test. The 3 interventions were performed by all participants in random order on 3 days separated by 48–72 hours.Results: The flexibility test scores improved significantly more after foam rolling as compared with static and dynamic stretching. With regard to muscle strength, only knee extension peak torque (pre vs. postintervention) improved significantly after the dynamic stretching and foam rolling, but not after static stretching. Knee flexion peak torque remained unchanged.Conclusions: Foam rolling is more effective than static and dynamic stretching in acutely increasing flexibility of the quadriceps and hamstrings without hampering muscle strength, and may be recommended as part of a warm-up in healthy young adults.

26 April 2018 in Journal of Sports Sciences
Verified
Journal Article
Closed access
CLChia-Lun Lee
Chia-Lun Lee
I-Hua ChuI-Hua Chu
I-Hua Chu
BLBo-Jhang Lyu
Bo-Jhang Lyu
WCWen-Dien Chang
Wen-Dien Chang
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
Warm-up is an essential component for optimizing performance before an exercise session. This study investigated that the immediate effects of vibration rolling (VR), nonvibration rolling (NVR), and static stretching as a part of a warm-up regimen on the flexibility, knee joint proprioception, muscle strength, and dynamic balance of the lower extremity in young adults. Compared with the preintervention, VR induced the range of motion of knee flexion and extension significantly increased by 2.5% and 6%, respectively, and isokinetic peak torque and dynamic balance for muscle strength and dynamic balance increased by 33%-35% and 1.5%, respectively. In the three conditions, most outcomes between VR and NVR were comparable; however, the participants had a significantly higher knee joint reposition error after NVR than after VR, indicating that NVR would have a hampering knee joint proprioception effect. In particular, compared with static stretching, VR significantly increased the quadriceps muscle strength by 2-fold and dynamic balance by 1.8-fold. These findings suggest that athletic professionals may take VR into account for designing more efficient and effective preperformance routine to improve exercise performances. VR has high potential to translate into an on-field practical application.

1 January 2020 in BioMed Research International
Verified
Journal Article
Open access
PDF file
Wen-Dien ChangWen-Dien Chang
Wen-Dien Chang
Li-Wei ChouLi-Wei Chou
Li-Wei Chou
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
Shuya ChenShuya Chen
Shuya Chen
Objectives. The aim of this study was to assess the relationships between functional movement screen (FMS), star excursion balance test (SEBT), agility T test, and vertical jump test scores and sports injury risk in junior athletes. We compared these assessments and the differences between groups with high and low risks of sports injury. Subjects and Methods. Eleven volleyball, 12 basketball, and 9 handball athletes were recruited. All participants followed the routine training in school sports teams. Weekly training schedules followed a similar pattern. The 32 junior athletes (age = 16.06 ± 0.21 years; height = 167.28 ± 6.32 cm; and body mass = 68.45 ± 9.67 kg) were assessed using the FMS, SEBT, agility T test, and vertical jump test in random order. The correlations of composite and individual item scores of these assessments were analyzed, and the differences between groups with high and low risks of sports injury were compared. Results. All participants completed the study protocol. No significant differences were observed between FMS, SEBT, agility T test, and vertical jump test scores in groups with high and low risks of sports injuries. Fair and moderate‐to‐good correlations were observed for anterior reach maximum of SEBT and deep squat (r = 0.47, P = 0.02) as well as inline lunge (r = 0.53, P = 0.01) of FMS. The hurdle step of FMS also exhibited moderate‐to‐good (r = 0.52, P = 0.01) and fair (r = 0.42, P = 0.04) correlations with posterior medial and posterior lateral reach maximum of SEBT, respectively. A fair correlation was observed between posterior lateral reach maximum of SEBT and rotary stability of FMS (r = −0.23, P = 0.03). Fair and moderate‐to‐good correlations were identified for agility T test and maximum anterior reach in the SEBT (r = −0.42, P = 0.04) and trunk stability push‐up in the FMS, respectively (r = −0.57 and P = 0.006). Conclusions. Junior athletes with a high risk of sports injury did not exhibit differences in terms of FMS, SEBT, and physical fitness test scores. Deep squat, hurdle step, inline lunge, and rotary stability scores in the FMS were correlated with the item scores in the SEBT, which may be due to the use of similar movement patterns. Scores for anterior reach maximum in the SEBT and trunk stability push‐up in the FMS were correlated with agility T test scores, suggesting a similar task requirement of trunk stability and dynamic weight shifting ability.

SCShu-Mei Chen
Shu-Mei Chen
FSFeng Chih Shen
Feng Chih Shen
JCJung-Fu Chen
Jung-Fu Chen
Wen-Dien ChangWen-Dien Chang
Wen-Dien Chang
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
Type 2 diabetes mellitus (T2DM) is significantly associated with osteoarthritis (OA). This study investigated the effects of two resistance exercise approaches on glycated hemoglobin (HbA1c) level and function performance. Enrolled were 70 older patients with both T2DM and knee OA. The dynamic group performed resistance exercises with an elastic resistance band. The isometric group underwent isometric contraction exercises. After the 12-week intervention, a significant within-group improvement (all p < 0.001) was observed for the chair stand test (CST; 10.8%, vs. 7.1%), timed up and go (TUG) test (12.6% vs. 7.6%), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) physical function subscale (62.3% vs. 36.1%), and overall WOMAC (54.5% vs. 34.5%) in the dynamic and isometric group, respectively. In addition, in terms of between-group differences, the dynamic group had significant improvements in CST (p = 0.011), TUG (p < 0.001), WOMAC physical function subscale (p = 0.033), and overall WOMAC (p = 0.036) scores compared with the isometric group. However, no significant change in HbA1c was observed in either group. In conclusion, the dynamic resistance exercise significantly improved muscle strength, dynamic balance, and physical function in this comorbid population; however, there was no notable difference in change in HbA1c among different resistance exercises.

PYPei-Hsin Yang
Pei-Hsin Yang
MLMeng-Chih Lin
Meng-Chih Lin
YLYi-Ying Liu
Yi-Ying Liu
CLChia-Lun Lee
Chia-Lun Lee
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
Pneumonia leads to changes in body composition and weakness due to the malnourished condition. In addition, patient family caregivers always have a lack of nutritional information, and they do not know how to manage patients’ nutritional intake during hospitalization and after discharge. Most intervention studies aim to provide nutritional support for older patients. However, whether long-term nutritional intervention by dietitians and caregivers from patients’ families exert clinical effects—particularly in malnourished pneumonia—on nutritional status and readmission rate at each interventional phase, from hospitalization to postdischarge, remains unclear. To investigate the effects of an individualized nutritional intervention program (iNIP) on nutritional status and readmission rate in older adults with pneumonia during hospitalization and three and six months after discharge. Eighty-two malnourished older adults with a primary diagnosis of pneumonia participated. Patients were randomly allocated to either a nutrition intervention (NI) group or a standard care (SC) group. Participants in the NI group received an iNIP according to energy and protein intake requirements in addition to dietary advice based on face-to-face interviews with their family caregivers during hospitalization. After discharge, phone calls were adopted for prescribing iNIPs. Anthropometry (i.e., body mass index, limb circumference, and subcutaneous fat thickness), blood parameters (i.e., albumin and total lymphocyte count), hospital stay, Mini-Nutritional Assessment-Short Form (MNA-SF) score, target daily calorie intake, total calorie intake adherence rate, and three-major-nutrient intakes were assessed during hospitalization and three and six months after discharge. Both groups received regular follow-up through phone calls. Furthermore, the rate of readmission resulting from pneumonia was recorded after discharge. During hospital stay, the NI group showed significant increases in daily calorie intake, total calorie intake adherence rate, and protein intake compared with the SC group (p < 0.05); however, no significant difference was found in anthropometry, blood biochemical values, MNA-SF scores, and hospital stay. At three and six months after discharge, the NI group showed significantly higher daily calorie intake and MNA-SF scores (8.2 vs. 6.5 scores at three months; 9.3 vs. 7.6 scores at six months) than did the SC group (p < 0.05). After adjusting for sex, the readmission rate for pneumonia significantly decreased by 77% in the NI group compared with that in the SC group (p = 0.03, OR: 0.228, 95% CI: 0.06–0.87). A six-month iNIP under dietitian and patient family nutritional support for malnourished older adults with pneumonia can significantly improve their nutritional status and reduce the readmission rate.

1 October 2013 in Osteoarthritis and Cartilage
Verified
Journal Article
Closed access
Nai-Jen ChangNai-Jen Chang
Nai-Jen Chang
CLC.-F. Lam
C.-F. Lam
CLC.-C. Lin
C.-C. Lin
WCW.-L. Chen
W.-L. Chen
CLC.-F. Li
C.-F. Li
MYM.-L. Yeh
M.-L. Yeh