[SalesForce] Ending position out of bounds

I have below trigger which passes string values to below class to do some changes for update. Please find the trigger.
Trigger:

trigger AccountFieldAutoUpdates on Account (before insert, before update) 
{

    String CalcCombinedABS = '';
    for(Account acc:trigger.new)
    {
        // Auto capitalization and translation
        if(acc.Ispersonaccount==true)
        {  
           String TempStr='';
           if(acc.FirstName!=null)
           {
            TempStr=AbbvieUtilitiesclass.translate(acc.FirstName);
            acc.FirstName=AbbvieUtilitiesclass.initCaps(TempStr);            
           }

            // Middle name
            if(acc.Middle_vod__c!=null)
            {
            TempStr=AbbvieUtilitiesclass.translate(acc.Middle_vod__c);
            acc.Middle_vod__c=AbbvieUtilitiesclass.initCaps(TempStr); 
            }
            //  Last Name            
            TempStr=AbbvieUtilitiesclass.translate(acc.LastName);
            acc.LastName=AbbvieUtilitiesclass.initCaps(TempStr); //// Error line
        }            
        else 
        {// Business Accounts            
            String sName = AbbvieUtilitiesclass.translate(acc.Name);
            sName= sName.substring(0,1).toUppercase() + sName.substring(1,sName.length());            
            acc.Name = sName;
        }


        //Auto Update HCI/HCO
        if(acc.IsPersonAccount)
            acc.HCP_HCI_abv__c = 'HCP';
        else
            acc.HCP_HCI_abv__c = 'HCI/HCO';

        // Auto Update ABS Concat
        CalcCombinedABS  = '';
        if(acc.Abbott_Best_Specialty_ABT__c != null && acc.Abbott_Best_Specialty_ABT__c != '')
        {
            CalcCombinedABS = acc.Abbott_Best_Specialty_ABT__c;
        } 
        if(acc.Abbott_Best_Specialty_Description_ABT__c != null && acc.Abbott_Best_Specialty_Description_ABT__c!= '')
        {
            if(CalcCombinedABS  == '')
            {
                CalcCombinedABS =acc.Abbott_Best_Specialty_Description_ABT__c;
            } 
            else
            {
                CalcCombinedABS  = CalcCombinedABS + '-' + acc.Abbott_Best_Specialty_Description_ABT__c;
            }         
        }
        if(acc.Combined_ABS_abv__c != CalcCombinedABS)
            acc.Combined_ABS_abv__c = CalcCombinedABS;

        // Added for 71 for Approved Email Consent Update upon Record Type Change

        String newAccRecordType = acc.Account_Record_Type_Name_ABT__c;         

        if(trigger.IsInsert && newAccRecordType != 'Prescriber' && newAccRecordType != 'Non-Prescriber with ABS')
            acc.Approved_Email_Opt_Type_vod__c = 'Never_vod';

        if(trigger.IsUpdate)
        {
            Account oldAcc = trigger.oldMap.get(acc.Id); 
            String oldAccRecordType = oldAcc.Account_Record_Type_Name_ABT__c;

            Boolean isPersonAcc = acc.IsPersonAccount;

            if(oldAccRecordType  != newAccRecordType && isPersonAcc) 
            {
                if(newAccRecordType == 'Prescriber' || newAccRecordType == 'Non-Prescriber with ABS')
                    acc.Approved_Email_Opt_Type_vod__c = '';
                else
                    acc.Approved_Email_Opt_Type_vod__c = 'Never_vod';
            }
        }
    }

}

Class:

public class AbbvieUtilitiesclass
{
    public static Map<String,String> M;
    public static String initCaps(String inputString)
    {
        if(inputString!= null)
        {
            system.debug('inputstring@'+inputstring); 

            if(!inputString.contains(' '))
            {
                String CapsName= inputString;
                      CapsName=(Capsname.substring(0,1)).toUppercase()+(CapsName.substring(1,CapsName.length()));
                      system.debug('CapsName@'+CapsName);
                return CapsName;
            }
            else 
            {
                 List<String> CapsName= inputString.split(' ');
                 String RetName='';
                    for(Integer i=0;i<CapsName.size();i++)
                    {
                        CapsName[i] = (CapsName[i].substring(0,1)).toUppercase() +(CapsName[i].substring(1,CapsName[i].length()));   ////  Error line
                        if(i>0)
                        {
                            RetName=RetName+' '+CapsName[i];
                        }
                        else RetName=CapsName[i];    
                    }
                    system.debug('Retname@'+Retname);
                    return Retname;
             }

         }
           //code added
         else
         {
             return null;
         }    
    }

    public static String translate(String str)
    {
        if(str==null)
        return null;    

        String TransMap = Abbvie_Custom_Settings__c.getValues('Main').Translation_Map_abv__c;

        if(TransMap != null && TransMap != '')
        {
            List<String> maps = TransMap.split(',');

            for (String key: maps)
            {
                List<String> keyval = key.split(':');
                str = str.replace(keyval[0],keyval[1]);//Get CORR Value
            }
        }
        return str;//english       
    }         
}

Please find the error I am facing now.

Apex script unhandled trigger exception by user/organization:
005F0000002gRMP/00DM0000001eGhW Source organization: 00DA0000000cASY
(null) AccountFieldAutoUpdates: execution of BeforeUpdate

caused by: System.StringException: Ending position out of bounds: 1

Class.AbbvieUtilitiesclass.initCaps: line 23, column 1
Trigger.AccountFieldAutoUpdates: line 32, column 1