diff --git a/.gitignore b/.gitignore
index c73142d8..8f2e1d03 100644
--- a/.gitignore
+++ b/.gitignore
@@ -140,3 +140,4 @@ cython_debug/
 
 # Pycharm
 .idea/*
+*.urdf
diff --git a/examples/neural_ik.py b/examples/neural_ik.py
index 9400fd98..333b99ce 100644
--- a/examples/neural_ik.py
+++ b/examples/neural_ik.py
@@ -57,7 +57,6 @@
 import adam
 from adam.pytorch import KinDynComputations
 
-
 DEFAULT_DESCRIPTION = "g1_mj_description"
 DEFAULT_DEVICE = torch.device("cuda" if torch.cuda.is_available() else "cpu")
 
diff --git a/src/adam/model/std_factories/std_joint.py b/src/adam/model/std_factories/std_joint.py
index 78892df9..12b335ff 100644
--- a/src/adam/model/std_factories/std_joint.py
+++ b/src/adam/model/std_factories/std_joint.py
@@ -131,7 +131,5 @@ def motion_subspace(self) -> npt.ArrayLike:
             return self.math.vertcat(z, z, z, axis[0], axis[1], axis[2])
         elif self.type in ["prismatic"]:
             axis = self.axis
-            zero = self.math.zeros(
-                3,
-            )
-            return self.math.vertcat(axis[0], axis[1], axis[2], zero, zero, zero)
+            z = self.math.zeros(1)
+            return self.math.vertcat(axis[0], axis[1], axis[2], z, z, z)
diff --git a/src/adam/parametric/model/parametric_factories/parametric_joint.py b/src/adam/parametric/model/parametric_factories/parametric_joint.py
index 1397463d..68ac7312 100644
--- a/src/adam/parametric/model/parametric_factories/parametric_joint.py
+++ b/src/adam/parametric/model/parametric_factories/parametric_joint.py
@@ -157,5 +157,5 @@ def motion_subspace(self) -> npt.ArrayLike:
             return self.math.vertcat(z, z, z, axis[0], axis[1], axis[2])
         elif self.type in ["prismatic"]:
             axis = self.axis
-            zero = self.math.zeros(3)
-            return self.math.vertcat(axis[0], axis[1], axis[2], zero, zero, zero)
+            z = self.math.zeros(1)
+            return self.math.vertcat(axis[0], axis[1], axis[2], z, z, z)
diff --git a/src/adam/parametric/model/parametric_factories/parametric_link.py b/src/adam/parametric/model/parametric_factories/parametric_link.py
index 552c0a99..da5f7b71 100644
--- a/src/adam/parametric/model/parametric_factories/parametric_link.py
+++ b/src/adam/parametric/model/parametric_factories/parametric_link.py
@@ -46,7 +46,7 @@ def __init__(
         original_volume, _ = self.compute_volume(length_multiplier=1.0)
         self.original_density = link.inertial.mass / original_volume
         self.link_offset = self.compute_offset()
-        (self.volume, self.visual_data_new) = self.compute_volume(
+        self.volume, self.visual_data_new = self.compute_volume(
             length_multiplier=self.length_multiplier
         )
         self.mass = self.compute_mass()
diff --git a/tests/test_mujoco.py b/tests/test_mujoco.py
index 64afd512..f90948b5 100644
--- a/tests/test_mujoco.py
+++ b/tests/test_mujoco.py
@@ -7,7 +7,6 @@
 from adam import Representations
 from adam.numpy.computations import KinDynComputations
 
-
 DESCRIPTION_NAMES = ["g1_mj_description", "aliengo_mj_description"]