Introduction
Literature review
In 21st century technology plays an important role in human life. Well among all its gadgets Smartphone is a fine revolution to our modern technology [1]. It has become one of the most ubiquitous communication device for past few years. People are not only using smart phones for communication, texting or browsing internet but it has greatly become a mode to play games of one's own choice, listen to music and watch videos. It would be better to say that it has become an essential part of life [2]. Hence, it has become an ideal device for malicious users [3].

Moreover it is a portable and accessible device that makes it possible to use it anywhere at any time. A research shows that the smart phone usage is estimated to be 2.87 billion users worldwide in 2020 [4]. It is said by youngster that they cannot exist without smart phone as it has become a part of their life. And it is no longer common to see youngsters carrying their smart phone in their hands while driving, eating or walking through a street [5].

Therefore its tempting features has persuaded our adolescents to spend a lot of their time on smart phones for socializing and communicating with others which is initially a habit but later on becomes an addiction [6]. Many studies have reported that adolescents spend approximately 10 hours on social media daily [7]

Where on one hand it provides us a lot of amazing features there on the other hand its widespread use has negative outcomes on physical and mental health. It's extensive use can be associated with musculoskeletal complications that is pain in neck and hand after continuous usage of many hours [5]

Frequent smart phone usage requires interaction of thumb and fingers to use mobile screen. Previous reports have shown that while carrying smart phone in your hands with an awkward posture of wrist may lead to wrist joint disorders. Repetitive hand's steady motion may prevent supply of nutrients to muscles and also decrease blood supply of hands thus leading to muscle fatigue [8]

A study by Fiaq and Huseyin et al in 2018 stated that phone use has been increased in recent years and it can causes many diseases of hands. It can lead to carpel tunnel

syndrome by affecting median nerve. It also stated that De Quervain's disease occurs commonly in smart phone users who type more than 50 messages a day. Furthermore there are applications used to send and receive messages on smart phone so researchers diagnosed a disease called bilateral extensor pollicis longus tendinitis also named as Whatsappitis [9].

Another study by Esra Erkol et al concluded after an observational study that overuse of smart phone can cause pain and numbness in thumb. It can also increase the median nerve's cross-sectional area and ultimately decreasing hand function and pinch strength [10]. However many other researches reported the relation of smart phone usage and musculoskeletal disorders which concludes that repeated fingers and thumb movements and repeated grasping activities could lead to dysfunction of upper limb [11].

Moreover a previous study by Nadia et al compared high frequency smart phone users and low frequency smart phone users and stated that function and pinch strength of hand was found to be decreased in high frequency smart phone users [1]. Further Zhiyong ming et all discussed the cause of a case report to aware people which stated that people who are using smart phones since three years can face upper limb impairments [12].

Despite such extensive usage of mobile phone, the effects on hand performance have not elaborated yet. Very few studies have been conducted on children or people of older age but not on young adults. People are experiencing pain and paresthesia in hand after using cell phone. So awareness among young adults who are addictive is required. Therefore this study will highlight the effect of using a smart phone on hand performance

N=112

Table 4: Smart Phone Addiction Score

Mean smart phone addiction score was found 42 out of total 60 with minimum 14 and maximum 57 scores. The score ranges from 10 to 60 with highest score being maximum presence of smart phone addiction. The cut off value for male is 31 and for female is 33.

N=112

Table 5: QUICK Disability of arm, shoulder and hand (Quick DASH)

74.1% have NO DIFFICULTY in Opening a tight or new jar, 50.9% have NO DIFFICULTY in Doing heavy household chores (e.g., wash walls, floors), 58% have MILD DIFFICULTY in Carrying a shopping bag or briefcase, 51.8% have MILD DIFFICULTY in Washing back, 96.4% have NO DIFFICULTY in Using a knife to cut food, 50% have MILD DIFFICULTY in Recreational activities in which take some force or impact through arm, shoulder or hand (e.g., golf, hammering, tennis, etc.).

N=112

Table 6: Disability of arm, shoulder and hand (Quick DASH): During the past week, to what extent has your arm, shoulder or hand problem interfered with your normal social activities with family, friends, neighbors or groups?

In 51.8% participants arm, shoulder or hand problem have interfered with normal social activities with family, friends, neighbors or groups, During the past week. 42.9% have felt no interference at all

N=112

Table 7: Disability of arm, shoulder and hand (Quick DASH): During the past week, were you limited in your work or other regular daily activities as a result of your arm, shoulder or hand problem?

53.6% were slightly limited in work or other regular daily activities as a result of arm, shoulder or hand problem, during the past week. 42% were not limited at all

N=112

Table 8: Disability of arm, shoulder and hand (Quick DASH): Please rate the severity of following symptoms in the last week:

42.9% have mild pain in Arm, shoulder or hand and 42% have no pain. 42% have no Tingling (pins and needles) in arm, shoulder or hand and 9.3% have mild Tingling (pins and needles) in arm, shoulder or hand.

N=112

Table 9: Disability of arm, shoulder and hand (Quick DASH): During the past week, how much difficulty have you had sleeping because of the pain in your arm, shoulder or hand?

42.9% experience mild difficulty in sleeping because of the pain in your arm, shoulder or hand, 33.9% have no difficulty in sleeping

N=112

Table 10: Disability of arm, shoulder and hand (Quick DASH): QUICK Disability of arm, shoulder and hand (Quick DASH)

Each item has 5 score scale which are calculated ranging from 0(no disability) to 100(most severe disability). Mean DASH score was found 31.36 out of 100 with minimum score 20 and maximum score 46. So participants were having mild to moderate level of disability

N=112

Table 11: Hand Dynamometer Reading (KG)

Mean reading from dynamometer was found 34KG with minimum 15KG and maximum 70KG.It is a device used to measure maximum isometric strength of hand and forearm muscles. The instrument is scored using force production in kg (0-90) or in pounds (0- 200).

N=112

Table 12: Independent sample t test: Gender Vs. Smart Phone Addiction Score

P value 0.231

P value shows that there is non-significant difference of Smart Phone Addiction Score between male and female although female were found having slightly higher Smart Phone Addiction Score than male.

The score ranges from 10 to 60 with highest score being maximum presence of smart phone addiction. The cut off value for male is 31 and for female is 33.

N=112