diff --git a/fixtracks/widgets/skeleton.py b/fixtracks/widgets/skeleton.py
index 65d6ba4..37140ce 100644
--- a/fixtracks/widgets/skeleton.py
+++ b/fixtracks/widgets/skeleton.py
@@ -50,6 +50,10 @@ class SkeletonWidget(QWidget):
         super().__init__(parent)
         self._skeletons = []
         self._current_skeleton = None
+        self._maxx = 0.
+        self._minx = 0.
+        self._maxy = 0.
+        self._miny = 0.
         self._slider = QSlider(Qt.Orientation.Horizontal)
         self._slider.sliderMoved.connect(self.on_sliderMoved)
         self._scene = QGraphicsScene()
@@ -65,7 +69,8 @@ class SkeletonWidget(QWidget):
         self.setLayout(lyt)
 
         self._view.fitInView(self._scene.sceneRect(), Qt.AspectRatioMode.KeepAspectRatio)
-        self._scene.changed.connect(lambda: self._view.fitInView(self._scene.sceneRect(), Qt.AspectRatioMode.KeepAspectRatio))
+        self._scene.changed.connect(lambda: self._view.fitInView(self._scene.sceneRect(),
+                                                                 Qt.AspectRatioMode.KeepAspectRatio))
 
     def clear(self):
         for i in range(len(self._skeletons)):
@@ -84,28 +89,48 @@ class SkeletonWidget(QWidget):
             self._scene.addItem(self._current_skeleton)
 
     def update(self):
+        logging.debug("SkeletonWidget: update")
         if len(self._skeletons) > 0:
             self._scene.addItem(self._skeletons[-1])
             self._current_skeleton = self._skeletons[-1]
         self._slider.setMaximum(len(self._skeletons))
         self._slider.setMinimum(0)
         self._slider.setValue(len(self._skeletons))
-        if len(self._skeletons) == 0:
-            self._slider.setEnabled(False)
+        self._slider.setEnabled(len(self._skeletons) > 0)
+        self._scene.setSceneRect(self._minx, self._miny, self._maxx - self._minx, self._maxy - self._miny)
+        self._view.fitInView(self._scene.sceneRect(), Qt.AspectRatioMode.KeepAspectRatio)
 
     def addSkeleton(self, coords, detection_id, brush, update=True):
+        def check_extent(x, y, w, h):
+            if len(self._skeletons) == 0:
+                self._minx = x
+                self._maxx = x + w
+                self._miny = y
+                self._maxy = y + h
+            else:
+                if x < self._minx:
+                    self._minx = x
+                if y > self._maxy:
+                    self._maxy = y
+                if x + w > self._maxx:
+                    self._maxx = x + w
+                if y + h > self._maxy:
+                    self._maxy = y + h
+
         boxx = np.min(coords[:,0])
         boxy = np.min(coords[:,1])
         boxw = np.max(coords[:, 0]) - boxx
         boxh = np.max(coords[:, 1]) - boxy
+        check_extent(boxx, boxy, boxw, boxh)
         item = Skeleton(boxx, boxy, boxw, boxh, coords, brush)
         item.setData(0, detection_id)
         self._skeletons.append(item)
         if update:
             self.update()
 
-    def addSkeletons(self, coordinates, detection_ids, brush):
-        num_detections = coordinates.shape[0]
+    def addSkeletons(self, coordinates:np.ndarray, detection_ids:np.ndarray, brush:QBrush):
+        num_detections = 0 if coordinates is None else coordinates.shape[0]
+        logging.debug("SkeletonWidget: add %i Skeletons", num_detections)
         for i in range(num_detections):
             self.addSkeleton(coordinates[i,:,:], detection_ids[i], brush=brush, update=False)
         self.update()