in humans , arm swing during gait is a complex and natural movement of the joints1 .
stephenson et al.2 suggested that movement of the shoulder joint affects the 
 ankle joint , thereby increasing range of motion and trunk stability2 .
arm swing during gait also minimizes the increase in 
 angular momentum and energy consumption , and has been reported to increase gait 
 stability3 .
ford et al.4 suggested that rotation of the trunk and 
 pelvis decreases when arm swing is limited , and that the gait speed increases due to the 
 increase in cooperation between the upper and lower extremities when there is no such 
 limitation .
consequently , a change in the angle of arm swing , due to increased speed , 
 affects the activeness of the latissimus dorsi , which belongs to the posterior oblique sling 
 system during gait5 .
this means that arm 
 swing during gait can affect movement of the legs , which is consistent with the results of 
 the present study , suggesting that muscle activity of the arms can affect that of the legs 
 as arm swing increases .
this study used an alternative approach compared with previous 
 studies by investigating the effect of minimizing arm swing while walking on the trunk and 
 gluteal muscles .
the subjects of this study included 13 adult males who voluntarily consented to participate 
 in the study and had no disease history or any problem with walking .
the study purpose and 
 methods were explained to the subjects , who provided informed consent according to the 
 principles of the declaration of helsinki before participating .
their average age , height , 
 and weight were 28.5  4.4  years , 174.5  6.6  cm , and 73.8  5.1  kg , respectively .
surface 
 electromyography ( emg ) was used to collect raw emg data using a wireless system .
surface 
 electrodes were placed on the following muscles : left side of the latissimus dorsi ( lateral 
 to the t9 spinous process over the muscle belly ) , right side of the gluteus medius ( proximal 
 third of the distance between the iliac crest and the greater trochanter ) , and gluteus 
 maximus ( the midpoint of a line running from the last sacral vertebrae to the greater 
 trochanter ) .
emg data were normalized using the maximum voluntary isometric contraction 
 ( mvic ) of each muscle , which was measured using the manual muscle test .
all participants 
 performed the minimized arm swing and full arm swing while walking on a treadmill for 1  min 
 at a speed of 2.5  km / h .
the minimization of arm swing while walking involved limiting the 
 arm swing within shoulder flexion and extension by 30 degrees using the guide bar . during 
 the full arm swing
while walking , the individual was allowed to swing the arm as much as 
 they wished .
repeated one - way anova was used to analyze the results ( spss ver . 20.0 
 statistical package ) .
the latissimus dorsi muscle activities during walking with a minimized arm swing ( 2.5  
 1.8% mvic ) were significantly decreased compared with those during walking with a full arm 
 swing ( 4.7  2.6% mvic ) .
the gluteus medius muscle activities during walking with a 
 minimized arm swing ( 12.0  5.3% mvic ) were significantly increased compared with those 
 during walking with a full arm swing ( 9.6  4.7% mvic ) .
the gluteus maximus muscle 
 activities did not differ significantly between the two types of walking ( 9.5  5.2% and 9.5 
  6.4% mvic , respectively ) .
based on this study , the latissimus dorsi muscle activities during walking with a minimized 
 arm swing were decreased compared with those during walking with a full arm swing .
the 
 gluteus medius muscle activities during walking with a minimized arm swing were increased 
 compared with those during walking with a full arm swing . walking with a minimized arm swing 
 may increase the load laterally and externally by decreasing latissimus dorsi muscle 
 activity as a result of the limited arm swing .
therefore , the gluteus medius muscle 
 activity was increased to maintain pelvic stability during walking with minimized arm swing . 

the latissimus dorsi and gluteus maximus muscles are linked obliquely to the posterior spine 
 by the thoracolumbar fascia ; this is referred to as the posterior oblique sling system1 . according to this result , which differs 
 from previous research
, the gluteus maximus did not differ significantly between walking 
 with minimized and full arm swing .
the gluteus medius plays an important role in 
 maintaining normal movement patterns of the pelvis and lower limbs , and is considered one of 
 the primary stabilizers in the pelvic area1 . walking with minimized arm swing
therefore , walking with minimized arm 
 swing would be an effective exercise for selective strengthening of the gluteus medius 
 muscle .
 [ purpose ] this study used an alternative approach compared with previous studies by 
 investigating the effect of minimizing arm swing while walking on the trunk and gluteal 
 muscles . 
 [ subjects and methods ] the subjects of this study included 13 adult males . 
 
 [ results ] the latissimus dorsi muscle activities during walking with a minimized arm swing 
 were significantly decreased compared with those during walking with a full arm swing . 
 the 
 gluteus medius muscle activities during walking with a minimized arm swing were 
 significantly increased compared with those during walking with a full arm swing . 
 
 [ conclusion ] therefore , walking with minimized arm swing would be an effective exercise 
 for selective strengthening of the gluteus medius muscle . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION