Checkboxes are used when there is a set of multiple options that may be selected by a user. If you only have a single checkbox use an on/off switch instead.
<fieldset>
<div class="row form-group">
<div class="col-sm-12">
<span class="input-group-checkbox">
<input id="checkbox1" class="checkbox" type="checkbox" disabled="disabled" name="checkbox1">
<label for="checkbox1" class="checkbox-label">Disabled</label>
</span>
</div>
</div>
<div class="row form-group">
<div class="col-sm-12">
<span class="input-group-checkbox">
<input id="checkbox2" class="checkbox" type="checkbox" name="checkbox2">
<label for="checkbox2" class="checkbox-label">Normal</label>
</span>
</div>
</div>
<div class="row form-group">
<div class="col-sm-12">
<span class="input-group-checkbox">
<input id="checkbox3" class="checkbox" type="checkbox" checked="checked" name="checkbox3">
<label for="checkbox3" class="checkbox-label">Checked</label>
</span>
</div>
</div>
</fieldset>
On/Off switches should not be used for multiple selection within a group of choices.